Abstract: This study reports an electrochemical sensor for detecting aspartame using square wave voltammetry (SWV) on ZnONP/BDDNP electrode. ZnONP/BDDNP was able to oxidize aspartame at a potential of 0.34 V in a phosphate buffer solution pH 2.0 with a current of 80.1 μA. The limit of detection (LOD) was found to be 0.07 μM, the limit of quantitation (LOQ) was 0.25 μM and sensitivity was 1.23 μA μM-1. The relative standard deviation (RSD) was 1.6%, less than 5% indicating that ZnONP/BDDNP has good precision. ZnONP/BDDNP showed better results compared with the BDDNP electrode. The developed method showed good linearity in the concentration range of 30-100 μM. This method was successfully applied to determine aspartame in beverage samples with a recovery range of 85-110%. This shows that ZnONP/BDDNP with the suggested method is potentially applied in practical used.

Abstract: Fish oil has been reported to have positive health effects because it is rich in n-3 essential fatty acids. This study aimed to determine the optimal conditions for achieving a high oil yield and omega-3 content from milkfish by-products using ultrasound-assisted extraction (UAE) combined with a d-limonene solvent. The Box-Behnken design (BBD) combined with response surface methodology was successfully used to determine the optimum extraction conditions for omega-3 fatty acids based on several factors: Temperature (30, 60 and 90 °C), solvent-to-sample ratio (2:1, 4:1 and 6:1 mL/g) and time (6, 38 and 70 min). The ANOVA results showed that sonication time (p < 0.05) and temperature (p < 0.05) had a significant influence on omega-3 fatty acids and the yield of extracted oil. The optimal extraction conditions for UAE were 68 min, 84 °C, and a solvent-to-sample ratio of 3:1 mL/g resulting in high oil recovery (21.95 %) containing omega-3 compounds (12.50 %). Additionally, the resulting oil was also further characterized by quality parameters (acid, peroxide, anisidine-total oxidation and iodine values) as well as the fatty acid composition. The developed milkfish oil met the IFOS™ (International Fish Oil Standards) criteria hence applicable for industrial oil production.

Abstract: The application of Kappaphycus alvarezii in the food system has attracted researchers due to its bioactive compounds, including tryptophan. The present study was conducted to extract tryptophan from K. alvarezii with the aid of sonication. A reduced multilevel factorial design was conducted to evaluate the effect of solvent, ultrasound power, duty-pulse cycle, time and temperature on the recovery of tryptophan. Analysis of variance suggested that the type of solvent and combination setting of power and duty-pulse cycle significantly influenced the extraction (p < 0.05). In contrast, extraction time and temperature did not alter the extraction (p > 0.05). The optimum was using ethanol, ultrasound power 80 %, pulse duty-cycle 0.8 s–1, extraction time 10 min, and temperature 25 °C and tryptophan concentration was 56.41 ± 2.42 mg L–1. Subsequently, a COnducto-like Screening MOdel for Real Solvent (COSMO-RS) was performed to clarify the impact of solvent affinity and polarity on the tryptophan extraction from K. alvarezii.

Abstract: This study aims to identify the quality of dry seaweed Gracilaria sp. cultivated in Brebes, West Java, Indonesia, and determine strategies to improve its quality through applying good aquaculture practices (GAP). The research methods used include field surveys, data collection, laboratory analysis, and application of good cultivation practices. The results showed that most of the required parameters met the specifications, except for moisture content, impurities, heavy metal Pb, microbial contamination (TPN), and mold/yeast contamination. Parameters that do not meet this requirement are related to aspects of GAP implementation that still need to be appropriate and need some improvement, especially in determining production locations, water management, product recording, and storage. Applying GAP also helps reduce negative impacts on the aquatic environment and increases the sustainability of seaweed farming. This research provides recommendations for seaweed farmers in Brebes Regency to implement GAP in cultivating Gracilaria sp. seaweed. This is expected to increase the quality of seaweed production, increase farmers’ income, and maintain the sustainability of seaweed cultivation. Further research can be conducted to deepen the understanding of applying GAP in seaweed farming and its long-term effects on the environment and the sustainability of seaweed farming.

Abstract: Roselle flower is an edible flower with health-beneficial bioactive compounds. In this study, red and purple roselle calyces were dried by foam-mat drying with different hydrophilic-lipophilic balance (HLB) of commercial emulsifiers as the foaming agents, including TBM, SP, and SSL. For a comparison is the roselle calyces powder from conventional drying. The mixture of emulsifiers of TBM and SP produces better foam and powder characteristics than a single emulsifier of SSL. HLB value and emulsifier mixture composition affect the foaming properties that influence the powder characteristics. The roselle variety also affected the foaming properties in which purple roselle calyces are better. The antioxidant activity seems to be affected by the foaming stability. The lack of conventional dried roselle calyces powder is the very low solubility indicated by undefined dissolution time. The formation of foam and the use of maltodextrin as a filler contribute to the foam mat-dried powder color.

Abstract: Background: Etlingera elatior inflorescence, a potential source for herbal tea, undergoes a drying process that could enhance the active ingredients and health benefits. This study introduces the use of ultrasound-assisted extraction (UAE) to improve conventional extraction and increase the yield of phytochemicals, thereby presenting a novel approach to functional foods and nutrition. Objective: This study aims to optimize the UAE method using the Box-Behnken Design (BBD), a statistical experimental design widely used in the field of functional foods and nutrition. The determination of phytochemicals was validated using the optimized UAE. Chlorogenic acid from the extract was analyzed using HPLC-DAD and compared with that from Indonesia. According to the development of herbal tea, the phytochemical contents and inhibition of DPPH scavenging antioxidant activity were examined for the three drying treatments compared to freeze-drying. Methods: Box-Behnken Design (BBD) was used to optimize the condition of UAE with three variables: solvent concentrations (70%, 85%, 100%), solid-to-solvent ratios (1:20, 1:15, 1:10), and temperatures (30°C, 50°C, 70°C). The TPCs and TFCs of the ethanol extract were analyzed as observed responses. Repeatability precision (%CV) and recovery were validated for the optimized UAE. HPLC-DAD analyzed the chlorogenic acid of the extract and compared it to the Thai E. elatior extract and Indonesia. In applying E. elatior tea, phytochemical contents, and DPPH∙, scavenging antioxidant activity was examined for three drying treatments and compared to the freeze-drying treatment. Results: The suggested condition of optimized UAE extraction was 70% ethanol, 50°C, and a 1:20 solid-to-solvent ratio. %Repeatability precision of TPCs and TFCs for the extract was significantly <5>90%. Freeze-drying and cabinet-drying treatments had significantly higher TPCs than others. Especially in freeze-drying treatment, the TFCs of the extract from Indonesia were significantly greater than those in Thailand (p<0.05). For DPPH∙ antioxidant activity, all treatments except freeze-drying of the extracts from Indonesia had higher inhibition of DPPH∙ antioxidant activity than those from Thailand. Conclusion: The optimized UAE extraction method was validated with high precision and accuracy. All drying treatments influenced the phytochemical contents and Inhibition of DPPH antioxidant activity in the inflorescences of both Thailand and Indonesia. © 2024 Functional Food Institute. All rights reserved.

Abstract: Citrus hystrix is a fruit native to tropical Southeast Asia and Southern China. The fruits and leaves are well-known spice ingredients in Asian dishes, but the peels are usually discarded, producing a large amount of waste despite the presence of phenolic compounds. Phenolic compounds are essential for scavenging reactive oxygen species (ROS) generated naturally during metabolism. This study aimed to investigate the profile of phenolic compounds (total phenolic content, total flavonoid content, and individual phenolic compounds) and antioxidant activities (2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, ferric reducing antioxidant power, and oxygen radical absorbance capacity) of Citrus hystrix peel ethanolic extract (CHPPE). Their functional properties in a biological model (cell viability and intracellular ROS) were also evaluated using Caco-2 cells under H2O2-induced oxidative stress. We identified 37 compounds, including flavonoids (26), phenolic acids (3), stilbenes (2), lignans (1), and other phenolic compounds (5). CHPPE contained (mg/g CHPPE) hesperidin (16.10±0.05), diosmin (1.95±0.08), neohesperidin (23.83±0.06), and naringin (2.39±0.03). CHPPE exhibited remarkable antioxidant activity, which significantly improving cell viability and reducing the presence of intracellular ROS. The cytoprotective effect of CHPPE was higher than that of ascorbic acid, indicating a strong natural antioxidative capacity. Our research reveals the potential of CHPPE as a functional ingredient in the food and pharmaceutical industries.

Abstract: Kappaphycus alvarezii is one of the most essential edible seaweeds in the global trade of marine products. The product quality will directly infuence the favor, odor, and impact on the human health of this edible seaweed. These functions are associated with volatile organic compound (VOCs) content and are controlled by seaweed cultivation sites. This study investigated VOCs using HS-SPME combined with GC–MS and multivariate analysis to determine the VOCs to be used as key markers for the quality of seaweeds from diferent cultivation sites. The HS-SPME factors, such as the amount of sample, extraction temperature, and extraction time, were optimized based on Box–Behnken design (BBD) and response surface methodology (RSM) for multi-response optimization (MRO). The precision of the approach varied from 1.17% (alkanes) to 6.30% (carboxylic acids) for repeatability and 3.93% (furans) to 16.64% (sesquiterpenoids) for intermediate precision. This method was applied to samples collected from nine diferent geographical regions in Indonesia. Principal Component Analysis (PCA) was used to determine data distribution from 48 compounds in K. alvarezii from those diferent cultivation sites. Based on PCA, four key marker VOCs, including heptadecane, 3-methylbutanoic acid, 2-pentyl furan, and 2-heptanone, were successfully established.

Abstract:

Abstract: Chamomile has been widely used as a functional tea due to its effects on several neurohormones, some of which are related to tryptophan. An analytical ultrasound-assisted extraction (UAE) technique was successfully optimized and validated to determine tryptophan levels in chamomile flowers. A Box-Behnken design,in conjunction with response surface methodology,was conducted based on 3factors and 3levels: Temperature (x1; 30, 50, and 70 °C), solvent composition (x2; 0, 40, and 80% methanol in water), and ultrasonic power (x3; 20, 60, and 100%). The main (x2) and quadratic effect of solvent (x2x2); quadratic of temperature (x1x1) and ultrasonic power (x3x3); also, the interaction of solvent-ultrasonic power (x2x3) and temperature-ultrasonic power (x1x3), significantly affected (p<0.05) the level of L-tryptophan in the extracts. Optimum extraction conditions were achieved by applying a temperature of 54 °C for 15 min using 17% methanol in water and 69% ultrasonic power. A high recovery (94.26%) was achieved with2extraction cycles. The coefficient of variation (CV) demonstrated that the developed method had a satisfactory level of precision (CV<5%) for repeatability and intermediate precision. To check the applicability of the method, the parts of 2types of chamomile flowers (German and Roman) were evaluated. This method was successfully applied to characterize chamomile flowers based on L-tryptophan levels.

Abstract: Young coconut mesocarp (YCM) contains considerable phenolic compounds that provide high antioxidant activity. However, the YCM is identified as an underutilized by-product in food industries. A novel functional food derived from YCM, viz., cookies, was proposed through this study to take advantage of the containing antioxidants. The cookies were prepared using regular flour (CR) or substituted with YCM powder at 8 (C8) or 16 % (C16). The macro components (carbohydrate, protein, fat and ash), in vitroantioxidant activities, and the level of individual phenolic compounds in the cookies were measured. The addition of YCM powder increased the crude fiber by up to 5 % and moisture content by about 2 – 3 %. Conversely, the fat level was lowered by 1 %. The in vitro antioxidant activities of cookies C8 and C16 were noticeably increased compared to the CR. The increase was attributable to the presence of phenolic compounds such as catechin and 3 caffeic acid derivatives, which were retained after the baking process. The addition of YCM changed the visual appearance by darkening the color of cookies which was indicated by lightness at 45.33 and 23.87; a* value was 17.30 and 18.97; b* value was 29.47 and 19.83; and chroma at 34.15 and 27.49, for C8 and C16, respectively. The addition of YCM also reduced the hardness due to the presence of moisture content in the incorporated cookies. Additionally, the addition of YCM was effective in prolonging shelf-life by increasing the oxidative stability of YCM-based cookies, indicated by the lower peroxide value (0.1 mEq O2·kg–1) after 4 months of storage compared to the regular cookies. YCM powder can be an alternative source of antioxidants, and it may be possible to include YCM powder in cookies and other pastries to increase their nutritional value and antioxidant activity to produce functional food

Abstract: Black glutinous rice (BGR) naturally contains phenolic compounds in free and conjugated form or bound to the structural matrix, which may affect its bioactivity. The degradation of the matrix cell wall by microbial activity during fermentation may endorse the release of bound phenolic compounds and enhance the availability of the compounds. This study aimed to assess the impact of tape fermentation on the profile of individual phenolic compounds and the antioxidant activity of BGR. Fermentation up to 72 h at 30 °C was performed by adding the cooked BGR with a tape starter (0.3% w/w). The fermentation for over 48 h increased free phenolic compounds while altering the composition of free, free-conjugated, and bound phenolic compounds. In comparison to the initial material, significant enhancement in the level of protocatechuic aldehyde (13 × ), caffeic acid (2 × ), vanillic acid (1 × ), vanillin (1 × ), p-coumaric acid (1 × ), ferulic acid (1 × ), and isoferulic acid (1 × ) was acknowledged in the final fermented product while sinapic and 2,4,6-trihydroxybenzoic acid was merely detected after 24 h of fermentation. As a result, antioxidant activity was also increased notably (p < 0.05) starting from 48 h of fermentation, while principal component analysis revealed that the activity was strongly contributed by 2,4,6-trihydroxybenzoic acid. Henceforth, the resulting tape fermentation of BGR can be considered a source of phenolic compounds that provide high antioxidant activity.

Abstract: Coriander (Coriandrum sativum L.) is among the most widely used medicinal and aromatic plants. It is well known for its multiple health benefits, most of which are correlated with its phenolic composition. Four phenolic compounds were identified in the extracts of aerial parts of coriander extracts, including caffeic acid, isoquercitrin, quercetin-3-O-glucuronide, and rutin. Caffeic acid was the major compound in the extracts. A Box–Behnken Design (BBD) was employed in conjunction with the response surface methodology (RSM) to develop an ultrasound-assisted extraction method for the determination of phenolic compounds in the aerial parts of coriander using the level of caffeic acid as the target response. The following working variables were evaluated: methanol level in the extraction solvent, temperature, sonication time, and liquid-to-solvent ratio. It was found that the methanol concentration is the most significant factor that influences the recovery of caffeic acid. The optimal extraction conditions were: 10 min as the extraction time, 70 °C as the temperature, 50% for methanol in water as the solvent, and 6.51 mL of solvent per gram of sample. The repeatability and reproducibility were calculated and RSD values below 6% were obtained in both cases. The new method was employed for the extraction of real coriander samples and it is suggested that this method could potentially be applied for quality control analyses.

Abstract: Patin (Pangasius micronemus) fish oil is rich in omega-3 fatty acids such as α-linolenic acid and eicosapentaenoic. To obtain the benefits of omega-3, it is necessary to develop an efficient extraction method for patin oil (PO). This study aimed to develop the microwave-assisted extraction (MAE) method for fish oil from patin. Three independent variables with three levels were priorly evaluated using Box–Behnken design, including temperature (30, 60, 90°C), solvent composition (30, 60, 90% of ethyl acetate in methanol), and solvent to sample ratio (10:1, 15:1, 20:1). The significant variables were then optimized by response surface methodology (RSM). A second order quadratic model of RSM suggested an extraction at 60°C with 56% ethyl acetate in methanol as an extraction solvent and a solvent-to-sample ratio of 20:1. A kinetics study under the optimum MAE conditions approved the complete recovery (38.84%) starting at 15 min of extraction time. The high precision of the MAE process was confirmed by the coefficient of variation less than 3%. Additionally, the microwave-produced fish oil was characterized by gas chromatography-mass spectrometry (GC-MS) to contain α-linolenic acid and eicosapentaenoic as omega-3. Henceforth, it has been demonstrated that microwave-assisted fish oil extraction developed in this study is efficient for high-quality PO production.

Abstract: Psidium laruotteanum is a subshrub Myrtaceae, native to the Brazilian savanna, and distributed in Central and South America. Here, the health beneficial compound piceid (reservatrol-3-mono-D-glucoside) is described for the first time in the genus Psidium. The ultrasound-assisted extraction from P. laruotteanum roots was optimized by a response surface methodology. A central composite design was used to assess six extraction variables. Optimal extractions were obtained with 62.5% MeOH in water at 69.1 C, amplitude of 70%, cycle of 0.5 s􀀀1, pH 5.7 and solvent–solid ratio of 40:1, for 10 min. The method showed excellent recovery (90%–95%) and precision (CV: 0.69% for repeatability and 0.43% for intermediate precision). This species appears as the most concentrated plant source of piceid reported to date (29.15 mgg􀀀1 in dry roots). Additionally, a very fast extraction (5 min) can afford 96% recovery of piceid from Psidium laruotteanum roots. It could be used as a natural and cheap source of piceid for several applications.

Abstract: This study aimed to determine the optimal UAE conditions for extracting anthocyanins from pigmented corn using the Box–Behnken design (BBD). Six anthocyanins were identified in the samples and were used as response variables to evaluate the effects of the following working variables: extraction solvent pH (2–7), temperature (10–70 ◦C), solvent composition (0–50% methanol in water), and ultrasound power (20–80%). The extraction time (5–25 min) was evaluated for complete recovery. Response surface methodology suggested optimal conditions, specifically 36% methanol in water with pH 7 at 70 ◦C using 73% ultrasound power for 10 min. The method was validated with a high level of accuracy (>90% of recovery) and high precision (CV < 5% for both repeatability and intermediate precision). Finally, the proposed analytical extraction method was successfully applied to determine anthocyanins that covered a wide concentration range (36.47–551.92 mg kg−1) in several pigmented corn samples revealing potential varieties providing more health benefits.

Civet coffee is the world’s most expensive and rarest coffee bean. Indonesia was the first country to be identified as the origin of civet coffee. First, it is produced spontaneously by collecting civet feces from coffee plantations near the forest. Due to limited stock, farmers began cultivating civets to obtain safe supplies of civet coffee. Based on this, civet coffee can be divided into two types: wild and fed. A combination of spectroscopy and chemometrics can be used to evaluate authenticity with high speed and precision. In this study, seven samples from different regions were analyzed using NIR Spectroscopy with various preparations: unroasted, roasted, unground, and ground. The spectroscopic data were combined with unsupervised exploratory methods (hierarchical cluster analysis (HCA) and principal component analysis (PCA)) and supervised classification methods (support vector machine (SVM) and random forest (RF)). The HCA results showed a trend between roasted and unroasted beans; meanwhile, the PCA showed a trend based on coffee bean regions. Combining the SVM with leave-one-out-cross-validation (LOOCV) successfully differentiated 57.14% in all sample groups (unground, ground, unroasted, unroasted–unground, and roasted–unground), 78.57% in roasted, 92.86% in roasted–ground, and 100% in unroasted–ground. However, using the Boruta filter, the accuracy increased to 89.29% for all samples, to 85.71% for unground and unroasted– unground, and 100% for roasted, unroasted–ground, and roasted–ground. Ultimately, RF successfully differentiated 100% of all grouped samples. In general, roasting and grinding the samples before analysis improved the accuracy of differentiating between wild and feeding civet coffee using NIR Spectroscopy

Edible flowers, including roselle, contain a varied composition of phenolic compounds that may inhibit the oxidative stress mechanism. Roselle-based tisane with appealing sensory properties is commonly consumed worldwide. However, the conventional hot-brew method may ruin the stability of thermolabile phenolic compounds during the tisane preparation. Hence, this study aimed to develop a new alternative brewing method linked with the new cold-brew method, which involves a lower temperature and applying ultrasound to maximize the extraction of phenolic compounds and to avoid degradation during the tisane preparation. The brewing factors, including particle size (10, 20, 30 mesh), temperature (4, 15, 26 °C), time (10, 20, 30 min), and ultrasound amplitude (20, 60, 100% of the maximum amplitude) have been optimized simultaneously using Box–Behnken design in conjunction with response surface methodology. Seven major phenolic compounds were identified by HPLC-DAD and classified into hydroxycinnamic acid derivatives (HCA) and flavonoids. The optimum extraction condition to reach the highest level of the studied phenolic compounds was set to brew roselle with particle size of 30 ± 3.25 mesh at 26 ± 1.32 °C for 18 ± 2.00 min applying 78 ± 5.64% ultrasound amplitude. This method successfully extracted almost all HCA and flavonoid during the first cycle with less than 10% CV and provided higher antioxidant activity in terms of DPPH (IC50 9.77 ± 0.01 µg mL−1), ABTS (IC50 8.05 ± 0.02 µg mL−1), and FRAP (IC50 10.34 ± 0.03 µg mL−1) than the roselle tisane prepared using the conventional method. Additionally, the resulting cold-brew product was stable for up to five days of storage.

A novel analytical method based on microwave-assisted extraction has been successfully optimized and validated to determine resveratrol from functional marmalade and cookies. The optimization was performed using a Box–Behnken design with three factors: solvent composition (60−100% and 10−70% methanol in water for marmalade and cookies, respectively), microwave power (250−750 W), and solvent-to-solid ratio (20:5−60:5). The main and quadratic effects of solvent composition significantly contributed to the recovery values (p < 0.005) for both kinds of samples. Additionally, the solvent-to-solid ratio and the quadratic effect of microwave power also influenced the resveratrol recovery from functional marmalade. Hence, the optimum condition for resveratrol extraction from marmalade (80% methanol, 500 W, solvent-to-solid ratio 40:5) and cookies (80% methanol, 250 W, solvent-to-solid ratio 20:5) was proposed. The extraction kinetics (5−30 min) was then studied to clarify the complete recovery of resveratrol from the food matrices resulting in 15 min as the optimum extraction time. The developed method showed a satisfactory precision indicated by the coefficient of variation (CV) lower than 5.70% for both repeatability and intermediate precision. To check the matrix effects, the developed MAE procedures were applied to a number of commercial marmalade and cookies. The high-fat and fiber cookies resulted in overestimated values due to the interfering ingredients. As a final point, the methods successfully measured the stability of naturally present resveratrol in grape-derived products while preparing functional marmalade and cookies.

Nowadays, dried edible flowers have become one of the eating habits of a healthy lifestyle. The most common way to consume dried flowers is via infused water (tisane). A number of studies on dried edible flowers have reported antioxidant activities mainly due to their phenolic compounds. This work has developed a new extraction method using ultrasound technology to determine phenolic compounds in 15 widely consumed edible flowers. Several extraction factors including pulse duty cycle (0.2, 0.6, 1.0 s⁻¹), temperature (10, 40, 70 °C), solvent-to-sample ratio (10:1, 20:1, 30:1 mL of solvent g ⁻¹ of sample), and solvent composition (0, 25, 50% methanol in water) have been optimized based on a Box–Behnken design coupled with response surface methodology. UPLC-PDA has been employed to quantify 12 major phenolic compounds (2,4,6-trihydroxy benzoic acid, protocatechuic acid, protocatechuic aldehyde, p-hydroxybenzoic acid, caffeic acid, vanillic acid, epicatechin, p-coumaric acid, ferulic acid, quercetin-3-rutinose, iso-ferulic acid, and quercetin-3-glucoside) in the extracts. The optimum extraction conditions for a 1 g sample were 30 mL of solvent (28% methanol in water) at 42 °C with 1.0 s⁻¹ of pulse duty cycle. Based on the kinetic study, the optimal extraction time was 10 min. The method was validated with high precision (CVs of repeatability and intermediate precision were lower than 7%) and high accuracy (recovery higher than 90%). Additionally, the proposed ultrasound-assisted extraction was successfully applied in the determination of phenolic compounds in 15 dried edible flowers.

Macroalgae are an essential basic ingredient for many industries from which numerous derived products with great economic value are manufactured. Each macroalga has a unique composition that might provide specific physical and chemical information that can be used as markers for authentication. Their compositions may differ depending on different factors, including geographical regions. Unsupervised exploratory techniques, namely principal component analysis (PCA) and hierarchical cluster analysis (HCA), and nonparametric supervised methods including support vector machines (SVMs) and random forests (RFs), were applied to the Vis-NIR spectroscopic data to standardize the quality of macroalgae based on three regional zones in Indonesia (Western, Central, Eastern). A total of 35 macroalgae samples from six islands in Indonesia were analyzed. The PCA and HCA results present a tendency for the samples to be distributed and clustered according to the type of their species. Meanwhile, the SVM successfully classified samples based on their regional zones, and when combined with five-fold cross-validation, acquired an accuracy of 82%. The RF model algorithm obtained an accuracy of 100%, 80%, and 82% for the training, test, and five-fold cross-validation, respectively.

D-psicose is a rare sugar, used as an alternative to the natural sweetener that provides 70% of sucrose’s sweetness, with low-calorie absorption in the human body. Considering the health-beneficial effect and high availability of D-psicose in raisins (the world’s most consumed dried fruit), it is of interest to establish a reliable analytical method to determine D-psicose content in these matrices. Herein, a new method for determining D-psicose content in raisins, using ultrasound-assisted extraction in conjunction with anion exchange chromatography with pulsed amperometric detection (UAE-HPAEC-PAD) systems, has been developed and validated. The stability of D-psicose and its precursor was priorly assessed by applying a specific ultrasound power (100 W) and pulse duty cycle (0.5 s⁻¹), with varying extraction temperatures (10, 25, 40, 55, 70, and 85 °C) and times (5, 10, 15, 20, and 25 min). The method was validated with high linearity (R² > 0.999), accuracy (89.78–101.06%), and precision (4.8% intra-day and 4.34% inter-day). A number of raisin products were checked during the method applicability assessment. A concentration of 520 mg kg⁻¹ was found in a specimen of commercial raisin matrix.

Abstract: Coconut (Cocos nucifera) fruit has attracted consumer interest due to its health benefits,
especially the consumption of coconut water produced from 6–7-month-old coconut fruit. Consequently,
by-products from young coconut fruit are also being expanded, including coconut mesocarp
containing phenolic compounds. Therefore, this study aimed to provide new applications for young
coconut mesocarp wastes. Specifically, optimizing the ultrasound-assisted extraction (UAE) of phenolic
compounds from coconut mesocarp using a Box–Behnken design in conjunction with response
surface methodology (RSM). The effects of three extraction variables, such as temperature (10–70 C),
solvent-to-sample ratio (20:1–10:1 mL/g), and pulse duty cycle (0.4–1.0/s) were examined on
the level of total phenolic content (TPC) and antioxidant activity of the extract. Subsequently, the
optimum UAE condition was predicted using RSM models with coefficients of determination (R2)
higher than 0.94, low prediction errors (less than 2.34), and non-significant lack-of-fit values (p < 0.05)
for the two responses. Extraction time was evaluated through kinetic (5 to 25 min) studies applying
the optimum extraction temperature (70 C), solvent-to-sample ratio (20:1 mL/g), and pulse duty
cycle (0.55/s). An efficient extraction was achieved within 5 min, resulting in an extract with
47.78 1.24 mg GAE 100/g DW for the total phenolic compounds and high antioxidant activity
(87.28 1.01% DPPH). Extraction by ultrasound was then concluded to facilitate a fast extraction
rate with high reproducibility (coefficients of variation were less than 3% in the levels of antioxidant
activity and phenolic compounds).

A rapid method based on Fourier transform infrared (FTIR) spectroscopy with multivariate data analysis was developed to identify and quantify aflatoxin contamination in peanuts. This technique was proposed over the chromatographic method due to faster, practical, and less reagent consumption as it is considered a non-destructive method. The spectra of samples were scanned using an FTIR spectrophotometer with attenuated total reflectance in the mid-infrared region (4,000−475 cm−1). Chemometric techniques for classification purposes using principal component analysis (PCA) and multivariate calibrations of partial least square (PLS) regression were used to establish the quantitative model and predict the levels of aflatoxin contamination in peanuts. PCA was successfully applied to classify the whole peanuts, those without shells, and those without shells and testa, based on PC1 and PC2 score plots. The determination of aflatoxin contamination levels using high-performance liquid chromatography coupled with a fluorescence detector (HPLC-FD) showed that 4 out of 20 samples (20%) resulted in 1.272–9.585 µg kg−1 for AFB1 and 0.448–2.943 µg kg−1 for AFB2. The method performance of aflatoxin analysis by HPLC-FD was validated by high coefficients of determination (R2 > 0.999) and low coefficients of variation (CV = 1.68−2.94%). Furthermore, PLS regression based on FTIR spectra at a selected wavenumber region (1,800−800 cm−1) provided a satisfactory prediction of aflatoxin contamination in peanut samples, including aflatoxin B1 [R2= 0.9995; root mean square error of calibration (RMSEC)= 0.1180; root mean square error of prediction (RMSEP) = 0.3000)] and aflatoxin B2 (R2 = 0.9999; RMSEC = 0.0119; RMSEP = 0.0595). Therefore, the developed method can be an analytical tool to identify the occurrence of aflatoxins in peanuts in the market.

Abstract: Red fruit oil (RFO) is a high-value oil that contains functional compounds, mainly phenolic compounds, providing antioxidant activity. Therefore, an optimal extraction method is essential to recover the RFO and phenolic compounds simultaneously. This research aimed to optimize the ultrasound-assisted extraction (UAE) for oil from red fruit using the Box-Behnken design combined with response surface methodology. The studied UAE factors, including sample-to-solvent ratio (1:3,1:2, and 1:1 g mL^-1), extraction temperature (60, 75, and 90 C), and pulse duty-cycle (0.20, 0.50, and 0.80 s????1). Analysis of variance revealed that the three studied factors significantly influenced the recovered RFO, while the level of total phenolic compounds in the extracts was defined merely by extraction temperature (p < 0.05). These significant factors were then included in the optimization models (R2 > 0.99, lack-of-fit p > 0.05). The proposed UAE setting by the multiresponse optimization was an extraction temperature of 67 C, a pulse duty-cycle of 0.50 s^-1, and a sample-to-solvent ratio of 1:2.5 g mL^-1. Subsequently, the extraction kinetic was evaluated, confirming full recovery at 60 min of extraction time. The developed method was then applied to extract six red fruit clones. Mbarugum clones provided high RFO recovery (9.60%), with an uppermost total phenolic compound of (42.63 mg GAE g^-1) among the six red fruit clones. Additionally, the resulting RFO showed eminent antioxidant activities, indicated by excellent values of IC50 DPPH (37.69 mg L^-1), IC50 FIC (30.43 mg L^-1), FRAP reducing power (63.55 mg AAEA g^-1), and IC50 ABTS (93.88 mg L^-1). In contrast with a wet rendering method, UAE enhanced the RFO recovery by 53.02%, resulting in a higher level of total phenolic compounds. Henceforth, the proposed UAE method is a promising technique to substitute conventional oil production in the food and pharmaceutical industries.

Abstract: Sidaguri (Sida rhombifolia) is one of the herbal components used in traditional medicine. The application of chemometrics in the standardization of herbal medicine is common. The objective of this study was to classify Sidaguri from different regions based on FTIR spectra with chemometrics of principal component analysis (PCA) and to correlate the antioxidant activities with FTIR spectra using the multivariate calibration of partial least square regression (PLSR). The extraction of Sidaguri powder was performed using ultrasound-assisted extraction (UAE) at optimum conditions. The obtained extracts were subjected to antiradical scavenging activities using DPPH (2,2’-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid) radicals. The PCA result shows that Sidaguri from different regions could be separated using 14 wavenumbers of FTIR spectra based on the PCA’s loading plot. PLSR regression using the second derivative FTIR spectra at wavenumbers of 3662–659 cm–1 could predict radical scavenging activities (RSA) of Sidaguri with R2 values of 0.9636 and 0.9024 for calibration and validation models, with RMSEC and RMSEP values of 1.45% and 2.65%, respectively. It can be concluded that FTIR spectra treated by PCA were reliable for classifying Sidaguri from different regions. At the same time, PLSR was accurate and precise enough to predict the RSA of Sidaguri.

Abstract The brewing properties of coffee products are defined by the chemical composition in the bean, including sugars and polyols. Some factors, such as coffee species and roasting, may affect the level of these compounds in the bean. A new analytical microwave-assisted extraction (MAE) method has been developed to extract sugars and polyols from the coffee bean. The studied extraction conditions for the MAE were temperature (30–80 C), solvent composition (0–50% ethanol in water), and solvent-to-sample ratio (10:1–30:1 mL solvent per g sample). A Box-Behnken design was applied to study the effect of extraction variables, and subsequently, the influential variables were optimized by response surface methodology (RSM). In addition to the main effect of the solvent-to-sample ratio, all quadratic effects significantly influenced (p < 0.05) the recovery of sugars and polyols from the coffee beans. RSM suggested the optimized MAE conditions: temperature 52 C, ethanol concentration in water 18.5%, and solvent-to-sample ratio 17:1. Under the optimum condition, a kinetics study confirmed that 15 min showed high precision and accuracy of the developed method. Ultimately, a real sample application of the developed MAE revealed that the new method successfully described the composition of sugars and polyols in regular and peaberry coffee beans. Additionally, the method also effectively characterized the green and roasted Arabica and Robusta coffee beans.

Abstract: Porang (Amorphophallus oncophyllus) is an indigenous tuber of Indonesia that rich in glucomannan. An alternative approach to produce porang oligo-glucomannan (POG) as prebiotic from porang glucomannan (PGM) was made by enzymatic hydrolysis using β-mannanase. This study aimed to produce POG under optimal conditions by controlled enzymatic hydrolysis process. The PGM flour contained 96.12% of indigestible carbohydrates. The optimum condition of enzymatic hydrolysis producing the highest reducing sugar was as follows: temperature 37 °C, pH 5.5, a ratio of enzyme to the substrate (E/S) 1:1000, and reaction time 4 h. HPLC analysis confirmed that 99.45% of the resulting POG consisted of oligosaccharides with a degree of polymerization (DP) 3. Hence, the PGM utilized in this study has been proven as a potential substrate for POG production. Additionally, the resulting POG was considered as a functional ingredient due to has prebiotic potential.

Abstract: Kulit koro pedang putih dapat digunakan sebagai sumber selulosa. Salah satu alternatif untuk meningkatkan aplikasi selulosa adalah dengan memodifikasi selulosa menjadi produk turunan selulosa yaitu Hydroxypropyl Methyl Cellulose (HPMC). Tujuan dari penelitian ini adalah melakukan optimasi terhadap sintesis dan karkaterisasi HPMC dari selulosa kulit koro pedang putih. Proses optimasi didahului dengan kajian literatur untuk menentukan kisaran titik percobaan dengan variabel terikat berupa molar subtitusi (MS) dan Derajat Subtitusi (DS). Diperoleh titik percobaan dengan variasi konsentrasi NaOH (5, 22,5, dan 40%), variasi Dimetil Sulfat (DMS) (40, 80, dan 120%), dan variasi Proilen Oksida (PO) (80, 120, dan 160%). Kemudian optimasi sintesis HPMC dilakukan dengan mengunakan Box-Behnken design (BBD) lalu dianalisis menggunakan Response Surface Methodology (RSM) Berikutnya HPMC dikarakterisasi meliputi molar subtitusi (MS), Derajat Subtitusi (DS), water holding capacity (WHC), oil holding capacity (OHC), lightness, rendemen, kristalinitas dan spektra FT-IR untuk mengetahui gugus fungsi HPMC. Hasil optimasi sintesis HPMC dari selulosa kulit koro pedang putih berdasakan RSM diperoleh titik optimum pada konsentrasi NaOH 23,11%, DMS 43,4% dan PO 81,8%. dengan karakterisasi kadar air 9,04% (wb); MS 0,15; DS 1,18; WHC 2,20 g/g; OHC 2,09 g/g; lightness 90,93; rendemen 114,78% dan kristalinitas 64%. Spektra FT-IR HPMC koro pedang putih terbaca pada bilangan gelombang 2924 cm^-1 (CH dan CH₂Streching), 1373 cm^-1 (CH₃Bonding), 1118 cm^-1 (C-O-C), 1319 cm^-1 (O-H Plane Bonding) dan 848, 68 cm^-1 (C-O-C pada 1,4 β glikosidic linkage) yang merupakan ciri khas dari gugus fungsional HPMC.

Abstract: Phenolic compounds are bioactive compounds that are also naturally found in red algae. To determine the level of these compounds in the red algae, spectroscopic or chromatographic determination was applied over the liquid extracts. Therefore, a prior extraction method is needed. The presented study aimed to develop the analytical ultrasound-assisted extraction (UAE) method to extract phenolic compounds from red algae. A Box–Behnken design (BBD) based on five factors included solvent composition (50–90% ethanol in water), extraction temperature (10–60 C), ultrasonic power (20–100%), pulse duty-cycle (0.2–1.0 s1), and solvent-to-sample ratio (10:1 to 30:1) was used to evaluate the effects of the studied factors. Subsequently, response surface methodology (RSM) was performed to define the optimum extraction condition to recover phenolic compounds from the alga matrices. The UAE condition suggested by RSM was: ultrasonic power 100%, pulse duty-cycle 1 s1, temperature 52.5 C, extraction solvent 50% ethanol in water, and solvent-to sample ratio 30:1. Kinetic studies confirmed 10 min to provide comparable recovery (p>0.05) than any longer extraction time. The acceptable values validated the developed method for repeatability (CV, 4.8%) and intermediate precision (CV, 5.7%). In addition, the accuracy of the method suggested a complete recovery for two extraction cycles. Furthermore, the method has successfully.

The pandemic situation experienced by the world is currently threatening food security in various regions including Indonesia. As a strategic step to reduce the impact on the agricultural sector, it is necessary to accelerate information to support the stability of production and also to distribute production results. Digital media in agriculture are needed to provide education with a variety of contents, such as technical production, marketing, and agricultural finance information. The Faculty of Agriculture of Universitas Gadjah Mada (UGM) has supported digital information dissemination through the Desa Apps application. Desa Apps aims to be an application platform that provides agricultural extension and develops digital farmer communities. The information that has been carried out by Desa Apps so far includes agrocomplex sector (agriculture, animal husbandry, and fisheries) problems related to cultivation methods and obstacles faced in the land such as attack by plant pest and disease. As a digital media, the Desa Apps has educated farmers and aquaculturists. This study evaluates whether farmers and aquaculturists under the auspices of the Faculty of Agriculture are interested in being able to get an education and at the same time be able to market their product directly to consumers with one application, the Desa Apps. The findings of the study showed that the pandemic period greatly affected the incomes of the assisted target community, and they required media that can help market their product. The decline in turnover due to pandemic conditions reached 70% with an average decrease of 39.2%. The method of selling products has changed from conventional to online sales by 20% of the total respondents. Changes in sales methods occurred due to distribution limitations due to regional and activity restrictions during the pandemic. Therefore, it is necessary to optimize the Desa Apps application as a digital media to support food security.

The algae Kappaphycus alvarezii is considered an important raw material for industrial practices, producing high economic value of various derived products. However, the quality of this commodity, which can be indicated by the level of phenolic compounds, may vary due to growth factors, including cultivation sites. An analytical UV‐Vis spectrophotometry method coupled with chemometrics was proposed to standardize the red alga based on the content of phenolic com pounds. The correlation between the UV‐Vis spectra and UPLC–PDA results, combined with a multivariate calibration of the K. alvarezii extracts, was analyzed. The extracts were prepared using an ultrasound‐based technique and subsequently subjected to UV‐Vis spectral measurements at 200–800 nm and UPLC–PDA at 260 and 330 nm. Chemometric techniques and partial least squares (PLS) were applied to the acquired data to build a reliable analysis of the phenolics in the K. alvarezii extracts. The result showed that the wavelength combination of 200 450 and 600–690 nm provided a valid method for quantitative analysis of the studied phenolics that belong to hydroxybenzoic acid, hydroxycinnamic acid, and flavonoid with a coefficient of regression (R2) > 0.96 in the calibra‐ tion and validation models, along with an RMSEC and RMSEP value < 8%. The method was then employed to characterize the K. alvarezii samples from 13 different cultivation areas. Principal com‐ ponent analysis (PCA) generated principal components that produced a clear distribution among the samples of K. alvarezii based on phenolic compounds corresponding to the geographical origin.

Sidaguri (Sida rhombifolia) is widely distributed in tropical and subtropical regions and has been reported to
possess many bioactive compounds that are beneficial for human health, including polyphenolics having antioxidant
activities. The objective of this study was (1) to optimize ultrasound-assisted extraction (UAE) of Sidaguri and (2)
to evaluate antioxidant activities of extracts resulting from the optimized condition using radical scavenging assay of
2,2′-diphenil-1-picrylhydrazyl (DPPH) and 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid. The optimum UAE
conditions obtained were solvent to solid ratio of 26:1, temperature of extraction of 45.45°C, methanol concentration
of 42%, power of sonication of 86%, and time of extraction of 5 minutes. Sidaguri obtained from locations of Kretek
and Ngemplak had the highest radical scavenging activity accounting for 83.69% ± 0.30% and 82.95% ± 0.49%,
respectively.

Having high protein content, jack bean is a promising resource for making tempe, a traditional fermented food commonly consumed in Indonesia. The current research aimed to investigate the effect of different cooking methods (boiling, steaming, frying, and baking) on a chemical, nutritional, and sensory aspects of jack bean tempe. The results showed that the highest protein content and antioxidant activity of the processed tempe were obtained by steaming method with a value of 380.3 g/kg and 57.8%, respectively. The steaming process could maintain protein and mineral contents as well as the antioxidant activity. The boiled tempe had six time lower of phytic acid compared to that of control. The baking and frying process increased five to six-fold of the fat content, while reduced the protein content by 30%. For the sensory evaluation, the baked tempe obtained the highest score. In conclusion, from a nutritional point of view, steaming is the best method for cooking jack bean tempe, while in term of sensory, baking is recommended.

Betacyanins have been reported to provide prominent health-promoting effects, in addition to contributing to the exotic color and pleasant palate of red dragon fruit that has been attracting universal interest for over a decade. An accurate determination of betacyanins in dragon fruit is important if we are to benefit from the nutraceutical features of these compounds. Seven betacyanin pigments have been identified and extracted by means of ultrasound-assisted techniques from red dragon fruit. Chemometric tools such as Box–Behnken Design (BBD) in conjunction with response surface methodology (RSM) have been successfully used to evaluate and optimize the relevant extraction variables i.e., temperature (A: 10, 35, 60 ◦C), solvent composition (B: 20, 50, 80% methanol in water), sample to solvent ratio (C: 0.1:10, 0.2:10, 0.3:10 g/mL), power (D: 20, 45, 70%), and cycle (E: 0.3, 0.5, 0.7 s–1). The results obtained from the analysis of variance (ANOVA) suggest that the solvent composition (p 0.0063), sample to solvent ratio (p 0.0126), and cycle (p 0.0302) are the most influential variables in betacyanin extraction. The optimal variable settings for ultrasound-assisted extraction (UAE) were a 54.6 ◦C extraction temperature, 0.3 s–1 cycle, 20% ultrasound power, 21.4% methanol in water solvent composition, 0.2:10 sample to solvent ratio, and a 5 min extraction time. The validation of the method for repeatability and intermediate precision provided excellent results at 1.56% and 2.94% respectively. Furthermore, the novel UAE method was successfully used for the determination of betacyanins content in red dragon fruit from different geographic origins.

Sweeteners have been used in food for centuries to increase both taste and appearance. However, the consumption of sweeteners, mainly sugars, has an adverse effect on human health when consumed in excessive doses for a certain period, including alteration in gut microbiota, obesity, and diabetes. Therefore, the application of non-nutritive sweeteners in foodstuffs has risen dramatically in the last decade to substitute sugars. These sweeteners are commonly recognized as high-intensity sweeteners because, in a lower amount, they could achieve the same sweetness of sugar. Regulatory authorities and supervisory agencies around the globe have established the maximum amount of these high-intensity sweeteners used in food products. While the regulation is getting tighter on the market to ensure food safety, reliable analytical methods are required to assist the surveillance in monitoring the use of high-intensity sweeteners. Hence, it is also necessary to comprehend the most appropriate method for rapid and effective analyses applied for quality control in food industries, surveillance and monitoring on the market, etc. Apart from various analytical methods discussed here, extraction techniques, as an essential step of sample preparation, are also highlighted. The proper procedure, efficiency, and the use of solvents are discussed in this review to assist in selecting a suitable extraction method for a food matrix. Single- and multianalyte analyses of sweeteners are also described, employing various regular techniques, such as HPLC, and advanced techniques. Furthermore, to support on-site surveillance of sweeteners’ usage in food products on the market, non-destructive analytical methods that provide practical, fast, and relatively low-cost analysis are widely implemented.

Edible flowers have been widely consumed for ages until now. The attractive colors and shapes, exotic aroma, and delightful taste make edible flowers very easy to attain. Moreover, they also provide health benefits for consumers due to the unique composition and concentration of antioxidant compounds in the matrices. Knowing the bioactive compounds and their functional properties from edible flowers is necessary to diversify the usage and reach broader consumers. Therefore, this reported review could be useful for functional product development, engaging the discussed edible flowers. We present a comprehensive review of edible flower composition and the functional properties of their antioxidant compounds, mainly phenolics.

An new method for the extraction of phenolic compounds from olive oil has been proposed before the chromatographic analysis by UPLC-PDA (Ultra-Performance Liquid Chromatography-PhotoDiode Array). Recoveries for 20 individual phenolic compounds were compared using three cartridges of solid-phase extraction including C-18, Diol, and DVB (DiVinylBenzene) based cartridges. Diol based cartridge produced the best retention efficiency. The optimized method uses a reduced amount of solvents and allows for the determination of most phenolics in oil samples in less than 10 min. A full discrimination among the most common olive oil varieties was achieved using the relative levels for specific phenolics in the sample. Therefore, based in this study, a fingerprint based on the relative levels for quercetin, luteolin, oleuropein and vanillic acid can be proposed to characterized varietal olive oils. In that way, a detailed composition about phenolic compounds of varietal olive oils would not be needed for discrimination purposes.

The growing demand for Spirulina (Arthrospira platensis) as a dietary supplement suggests that a rapid and reliable method to determine its saccharides and polyols content would be of great interest. Additionally, the impact of these microalga growing conditions may have on such content would be really useful for Spirulina producers. This manuscript presents the development and validation of a new analytical microwave-assisted extraction (MAE) method as the first step in determining saccharides and polyols in spirulina samples. A Box Behnken design has been employed to evaluate three extraction variables, viz., temperature (x1: 30, 55 and 80 C), solvent composition (x2: 0, 25, and 50% ethanol in water), and solvent to sample ratio (x3: 10:1, 20:1, and 30:1 mL of solvent per g of sample). These extraction variables have been optimized by Response Surface Methodology (RSM). Under the optimal conditions that have been thereby established (i.e., 30 C, 50% ethanol in water, and 30:1 solvent to sample ratio), a kinetic study has been performed with full recovery in 15 min. Subsequently, the developed MAE method was validated by determining the number of parameters, including linearity, LODs, LOQs, accuracy, and precision. Finally, the resulting MAE method was successfully applied to determine saccharides and polyols contents in a number of Spirulina samples that had been cultivated in varying salinity media. Five saccharides and polyols were identified in Spirulina, i.e., inositol, glycerol, sorbitol, glucose, and maltose. The total amount of the compounds of interest in the Spirulina that had been cultivated in a higher salinity media (17 and 25 g L1 of sodium chloride in water) was six-folds higher than the one cultivated in low saline water (0 and 3 g L1 of sodium chloride in water). This substantial content difference was mainly explained by the considerable increment in glycerol and glucose contents when grown in a more saline medium. Therefore, it has been demonstrated that the new method is suitable to determine saccharides and polyols contents in different Spirulina samples.

Roselle (Hibiscus sabdariffa L.), as an edible flower, has long provided an array of positive effects on human health. This benefit is a result of phenolic compounds that are naturally present mainly in the calyx. Plentiful medicinal remedies and functional foods based on this flower are available worldwide, as supported by the studies of phenolic compounds in recent decades. This paper aims to provide a comprehensive review of the composition, biological activity, and beneficial effects on human health of phenolic compounds in roselle. This review was performed in accordance  with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. A structured search in the published literature for phenolics compositions in roselle was required prior to the evaluation on the validity of the reported analytical methods. Reliable identification and quantification of phenolic compounds in roselle can be achieved by employing the proper extraction and separation methods. With ample alternative analytical methods discussed here, this review provided an aid for comprehending and selecting the most appropriate method for a particular study. The applications of the analytical methods highlighted indicated that phenolic acids, flavonoids, and their derivatives have been identified and quantified in roselle with a range of biological activities and beneficial effects on human health. It was also disclosed that the composition and concentration of phenolic compounds in roselle vary due to the growth factors, cultivars, and environmental influence. Finally, apart from the research progress carried out with roselle during the last ten years, this review also proposed relevant future works.

Porang (Amorphophallus oncophyllus) is an indigenous tuber of Indonesia that rich in glucomannan. An alternative approach to produce porang oligo-glucomannan (POG) as prebiotic from porang glucomannan (PGM) was made by enzymatic hydrolysis using β-mannanase. This study aimed to produce POG under optimal conditions by controlled enzymatic hydrolysis process. The PGM flour contained 96.12% of indigestible carbohydrates. The optimum condition of enzymatic hydrolysis producing the highest reducing sugar was as follows: temperature 37 °C, pH 5.5, a ratio of enzyme to the substrate (E/S) 1:1000, and reaction time 4 h. HPLC analysis confirmed that 99.45% of the resulting POG consisted of oligosaccharides with a degree of polymerization (DP) 3. Hence, the PGM utilized in this study has been proven as a potential substrate for POG production. Additionally, the resulting POG was considered as a functional ingredient due to has prebiotic potential.

The acid dissociation constant (pKa) is the fundamental physicochemical properties required to understand the structure and reactivity of boronic acid-based material as a sensor that identifies carbohydrates. However, there is a lack of comprehensive study on the impact of the substituent on the pKa of monosubstituted phenylboronic acid in aqueous and non-aqueous solutions. In this work, extensive experimental data on the pKa of monosubstituted phenylboronic acid in an aqueous solution was reviewed and compared in terms of accuracy. In addition, computational, were used to predict and investigate the impact of the substituent on the pKa for a series of monosubstituted phenylboronic acid in an aqueous solution at the molecular level. Good agreement was observed between predicted and literature pKa values of monosubstituted phenylboronic acid in the aqueous solution. While some deviations exist, predominantly with fluorine-containing phenylboronic acid, the COSMO-RS model is proficient at predicting the pKa of boronic acid in an aqueous solution with the accuracy of ±1.5 pKa. Subsequently, the model was used to predict the pKa of boronic acid in the non-aqueous solution, which data is not available in the literature. Furthermore, an excellent relationship is observed between the acidity of para-substituted, and to some extent, meta-substituted phenylboronic acid with the atomic charge of acidic hydrogen calculated using Natural Bond Orbital (NBO) Population Analysis. In contrast, the steric hindrance and the existence of other molecular forces might influence the acidity of ortho-substituted phenylboronic acid. The gathered information in this work could be of benefit for the understanding of the acidity of the boronic acid-based materials not only as a sensor but also in many diverse areas.

Ultrasound-assisted extraction (UAE) has been optimized to improve the current cassava starch production by conventional maceration for the extraction method. Evaluation of several extraction parameters disclosed significant effects (p < 0.05) by three studied factors (ultrasound power, x1; pulse duty-cycle, x2; and solvent to sample ratio, x3). Subsequently, a Box-Behnken design (BBD) in conjunction with response surface methodology (RSM) was employed to optimise the three factors at three levels: x1 (30, 60, 90%), x2 (0.3, 0.6, 0.9 s–1), and x3 (10:1, 20:1, 30:1). The model built for the RSM was validated through the coefficient of determination (R2 > 0.95), prediction error (2.12%), and lack-of-fit (0.71) values. The model validation suggested that the RSM was adequate for the observed data at the 95.0% confidence level. The optimum yield of cassava starch extraction was achieved by applying 90% for ultrasound power, pulse duty-cycle of 1.0 s–1, and solvent to sample ratio of 30:1 with 10 min extraction time. Finally, the UAE produced starch with a purity of 88.36% and a lower viscosity than the commercial sample due to the granules’ size alteration. Hence, apart from speeding up the extraction process, UAE was worthwhile for the starch modification that could maintain the viscosity at a lower value (1920 cP) than the commercial starch (1996 cP) at the highest studied temperature treatment of 70 ◦C.

Patin fish oils (PFOs) from fifteen different origins was evaluated the antioxidant activity using 2,2’-diphenyl-1-picrylhydrazil (DPPH) radical scavenging. All PFO samples were analyzed using Fourier Transform Infrared (FTIR) spectroscopy. The spectra were recorded in absorbance mode and processed statistically using multivariate chemometric techniques, including Principal Component Analysis (PCA), Principal Component Regression (PCR) and Partial Least Squares (PLS). PCA was used to classify PFOs from different origins, while PLS and PCR was used to predict the antiradical activity of PFOs based on FTIR spectra. The result showed that radical scavenging activity (%RSA) of PFO from Demak and Boyolali (Central Java) had high value than others, 40.88 ± 0.18% and 40.71 ± 0.07%, respectively. PCA could successfully classify PFOs from fifteen different origins based on the absorbance of FTIR spectra. PCR using the first derivative spectra at 3005-650 cm-1 could predict %RSA of PFOs with R2 value of 0.9987 and 0.9982 in calibration and validation models, with RMSEC and RMSEP were 0.609 and 0.734, respectively.

The use of herbal medicine to treat several diseases has increased in the past few years. One of the plants that can be used for herbal medicine is Sida rhombifoila Linn either using whole part or leaves part. S. rhombifolia, known with Indonesian name as Sidaguri, belongs to the family of Malvaceae. The objective of this review was to highlight the chemical composition and biological activities of S. rhombifolia. During performing this review, several abstracts,  reports, and original articles were reviewed from several databases such as Scopus, Science direct, Springer, PubMed and Google Scholar. The keywords used were Sida rhombifolia or “Sidaguri”, phytochemical, pharmacological activities such as antioxidant, antidiabetic, anti-inflammatory, wound healing, analgesic, cytotoxic, antiproliferative, and anticholinesterase activity. S. rhombifolia Linn is very potential to be used as herbal medicine due to some active compounds contained in this plant including phenolic, flavonoid, saponin, and alkaloid. These compounds were responsible for its several pharmacological activities such as antidiabetic and hepatoprotective.

Electrochemical biosensors have attracted a tremendous attention for many researchers recently due to its facile synthesis process, tunability easiness by tailoring the material properties or composition, and wide range of biological analyte types detection. To obtain an excellent electrochemical biosensor performance, a material that facilitates fast electron transfer, large surface area, excellent electrocatalytic activity, and abundant available sites for bioconjugation is immensely needed. Metal-organic frameworks in the two-dimensional form (2D MOFs) provide all of the criteria needed as the sensing material for electrochemical biosensors application. However, the design and preparation of 2D MOFs, which have high stability and sensitivity as well as good selectivity for biological analyte detection, is still quite challenging. This review provides the recent studies and development of 2D MOFs as electrochemical biosensor. A detailed discussion about 2D MOFs structures, their synthesis strategy and control, 2D MOFs materials in electrochemical biosensor application, and the future challenges is thoroughly explained in this review. Hopefully, this review will also provide a new inspiration to advance future studies of 2D MOFs materials development as electrochemical biosensor.

The present research intends to develop a new method based on headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) for the detection and determination of patin fish oil adulterated with different percentages of palm oil, because it is a cheaper vegetable oil. Five variables that affect headspace generation (incubation time and temperature, amount of sample, injection volume, and pre-heating time) have been optimized by means of a Box Behnken design in combination with Response Surface Methodology. Then, repeatability and intermediate precision have been studied where coefficients of variation lower than 10% were obtained. This new method has been applied to several samples of patin fish oil adulterated with palm oil at 20 different levels (5–50% palm oil content). The results have confirmed the suitability of the HS-GC-IMS for a rapid, easy, and reliable detection and discrimination of adulterated oil samples since a characteristic fingerprint that allows 100% successful discrimination between adulterated and unadulterated patin oil samples was achieved. Finally, a regression model has been developed to determine each sample’s adulteration level with an error lower than 10% and a coefficient of determination greater than 0.95.

P

The usage of food additives must respect the general legislation in force in the country and requires a reliable analytical method for surveillance. This research aimed to develop a high-performance liquid chromatography with diode array detection (HPLC-DAD) method for the
simultaneous determination of seven food additives and caffeine in powdered drinks. Three factors likely to affect the chromatographic separation, namely, mobile phase composition at the beginning (x1, 0–10% of the amount of methanol in the phosphate buffer) and the end (x2, 60–100% of the amount of methanol in the phosphate buffer) of the gradient program and pH (x3, 3–7), were evaluated with the aid of a Box–Behnken Design (BBD). Subsequently, multi-response optimizations for chromatographic resolutions (Rs) and analysis time were performed using the response surface methodology (RSM) in conjunction with the desirability function (DF). Complete separation (Rs > 1.5) of seven food additives and caffeine was achieved in less than 16 min by applying 8.5% methanol in the phosphate buffer at the beginning and 90% at the end of the gradient program, in pH 6.7. The developed method was validated with low limits of detection (ranging from 1.16 mg kg–1 (sodium saccharin) to 3.00 mg kg–1 (acesulfame potassium)), low limits of quantification (ranging from 3.86 mg kg–1 (sodium saccharin) to 10.02 mg kg–1 (acesulfame potassium)), high precision (CV < 4%), and high accuracy (recoveries from 95 to 101% at 80, 100, and 120% of the target concentration). The method was successfully used to assess the seven food additives and caffeine in commercially available powdered drinks.

Mangosteen, or Garcinia mangostana L., has merged as an emerging fruit to be investigated
due to its active compounds, especially xanthone derivatives such as α -mangostin (AM), γ-mangostin (GM), and gartanin (GT). These compounds had been reported to exert some pharmacological activities, such as antioxidant and anti-inflammatory, therefore, the development of an analytical method capable of quantifying these compounds should be investigated. The aim of this study was to determine the correlation between FTIR spectra and HPLC chromatogram, combined with chemometrics for quantitative analysis of ethanolic extract of mangosteen. The ethanolic extract of mangosteen pericarp was prepared using the maceration technique, and the obtained extract was subjected to measurement using instruments of FTIR spectrophotometer at wavenumbers of 4000–650 cm–1 and HPLC, using a PDA detector at 281 nm. The data acquired were subjected to chemometrics analysis of partial least square (PLS) and principal component regression (PCR). The result showed that the wavenumber regions of 3700–2700 cm–1 offered a reliable method for quantitative analysis of GM with coefficient of determination (R2) 0.9573 in calibration and 0.8134 in validation models, along with RMSEC value of 0.0487% and RMSEP value 0.120%. FTIR spectra using the second derivatives at wavenumber 3700–663 cm–1 with coefficient of determination (R2) >0.99 in calibration and validation models, along with the lowest RMSEC value and RMSEP value, were used for quantitative analysis of GT and AM, respectively. It can be concluded that FTIR spectra combined with multivariate are accurate and precise for the analysis of xanthones.

Objective: This study aimed to evaluate the antidiabetic and antidepressant effects of banana peel flakes in streptozotocin-induced diabetic rats.
Methods: Twenty-five male Wistar rats were classified into five groups with different treatments. Groups I to IV were diabetic rats model groupsthat consumed only standard diet, standard diet containing 5%, 10%, and 20% of banana peel flakes, respectively. While group V was a healthy
control group fed a standard diet. Immunohistochemistry staining was measured to examine serotonin expression in the colon and pancreas.
Results: The diabetic rats treated with 20% banana peel flakes had a lower blood glucose concentration (p<0.05) compared with diabetic control and showed a shorter duration of immobility time (p<0.05) than the healthy control. Additionally, compared with diabetic control, the diabetic rats treated with 5% banana peel flakes showed higher serotonin expression (p<0.05) in the colon. In contrast, serotonin expression in the pancreas did not show any significant difference (p>0.05).
Conclusion: The present study disclosed that the banana peel flakes provided an antidepressant effect in the diabetic rats model, which might occur through the mechanism of controlling blood glucose concentration.

Simple, rapid, and reproducible methods for determining the acid value (AV), peroxide value (PV), and saponification value (SV) of patin fish oil (PFO) were developed using Fourier Transform Infrared (FTIR) spectroscopy combined with chemometrics of Principal Component Regression (PCR) and Partial Least Square (PLS). The relationship between actual values was determined using AOCS method and predicted value was determined with FTIR spectroscopy and chemometrics. From the validation work, the high coefficient of determination (R2) reached up to > 0.99. This study concluded that by means of FTIR spectra that combined with PCR and PLS technique can be used to determine AV, PV, and SV of PFO.

Because of their antioxidant and anti-free radical capacities, the phenolic compounds of olives gained growing interest.The aim of this work is to determine the harvest optimal period of two Algerian olive varieties (Chemlal and Blanquette de Guelma) harvested at four stages of maturity which will allow the best equilibrium between the olives’ composition in phenolic compounds and their antioxidant activities.
Phenolic compounds were determined by colorimetric methods and by UPLC-PDA. The antioxidant activity of olive extracts was assessed by measuring the reducing power, the antiradical activity toward DPPH radical andABTS.
Results confirm that the process of maturation and the variety of olives affect considerably the phenolic compounds and their antioxidant activity. As a consequence, a significant decrease in the antioxidant activity (reducing power and antiradical activities) of the olive fruits is observed. The relative antioxidant capacity index (RACI), which represents the mean scores of the antioxidant activities, showed that the highest indices were obtained by the green stage for Chemlal and spotted green stage for Blanquette de Guelma.
The harvesting can occur when the olives are in the spotted green stage, corresponding to the middle of December. This period allows a good combination between the phenolic content and antioxidant activity.

Rice, especially the pigmented varieties, contains a higher level of melatonin (N-acetyl-5-methoxytryptamine), which is used in treatment for sleeping disorders and for improving mood. It has potent antioxidant properties, anti-obesity, and anti-inflammatory, thus potential as the basis for functional food development. The purpose of the study was to examine how the various rice attributes and demographic characteristics affect the willingness to pay of Indonesian consumers on functional rice. Multi-Factor Categorical Design (MFCD) and Balanced Incomplete Block Design (BIBD) have been used to study multiple non-quantitative factors, including different rice varieties and health benefits information on the label (x1, 3 levels: white rice, brown rice-label, and red rice-label), price (x2, 2 levels: low and high), and rice producers (x3, 3 levels: international brand, established national brand, and new national brand). Data collection was administered through an online questionnaire survey to 204 respondents, living in four major Indonesian islands: Java, Bali, Sumatra, and the Moluccas. The results showed that despite the health benefits of the melatonin contained in the whole brown and red rice, Indonesian consumers still preferred conventional white rice over the aforementioned rice varieties. Price was recognized as the main attribute affecting the selection of functional rice, whilst rice producers gave less impact on willingness to pay. The results indicated that cultural value, consumers’ knowledge of melatonin, consumers’ health status, and consumers’ income were the sources of heterogeneity in consumers’ willingness to pay for functional rice.

Jack bean is one of underutilized legume. In Indonesia jack bean tempeh is one traditional product from Indonesia, using jack bean tempeh as food ingredient. So far, scientific information on jack bean tempeh is scarce and thus this article aims to document the updated knowledge of jack bean tempeh. Tempeh is a sliceable, cake-like product made of dehulled cooked jack bean, penetrated and fermented by a mixed microbiota dominated by filamentous fungi. Jack bean as one type of pulses are a rich source of protein in the human diet and their consumption has been associated with the prevention of chronic diseases. The beneficial effect in human health has been related to their micronutrients, phytochemical bioactive compounds and recently BP (bioactive peptides).

The growing interest in spicy foods leads to the global demand for spices, particularly dried chili. This study aimed to assay both aflatoxin (AFs) and ochratoxin A (OTA) contamination using an integrative method of morphological identification, molecular detection, and chromatography analysis on dried chili provided from traditional and modern markets in Indonesia. The results showed that total fungal infection ranged from 1-408 × 103 CFU/g. Eighty percent of the chili obtained from both the traditional and the modern markets were infected by Aspergillus spp., in which 50% of the infections were identified as A. parasiticus and A. flavus. A complete set of targeted genes involved in AF production and OTA were detected in two isolates of A. flavus and one isolate of A. carbonarius, respectively. The levels of AFs B1, B2, and OTA in the contaminated dried chilies were in the range of 39.3–139.5 µg/kg, 2.6–33.3 µg/kg, and 23.7–84.6 µg/kg, respectively. In contrast, no AFs G1 and G2 were detected. This study showed that the fungal infection of Indonesian dried chili occurs both in the field and during storage; thus, it is suggested to implement good agricultural and handling processes.

Joruk is a traditional fishery product made by spontaneous fermentation process using lactic acid bacteria by salting method, followed by fermentation process. Hydrolysis of proteins with the pepsin and a combination of pepsin and trypsin enzymes by in vitro can produce bioactive peptides. The aims of this study were to investigate the change of soluble protein and lactic acid content in oci fish joruk (Rastrelliger kanagurta) and to determine the influence of the enzyme hydrolysis on the antioxidant activity of joruk. The raw material used in this highest study was the oci fish obtained from Gorontalo, Indonesia. The produced joruk was added with the concentration of palm sugar 10%, 20% and 30% then fermented for 8 days, 10 days and 12 days. Protein hydrolysis using the pepsin enzyme and a combination of pepsin and trypsin enzyme. The results showed that the addition of palm sugar and fermentation time can reduce soluble protein and increase the lactic acid content. The highest antioxidant activity was found in joruk hydrolysate that hydrolyzed by pepsin enzyme with the addition of 30% palm sugar and 12 days fermentation, with a value of 5.28%.

The aroma of rice essentially contributes to the quality of rice grains. For some varieties, their aroma properties really drive consumer preferences. In this paper, using a dynamic headspace solid-phase microextraction (HS-SPME) system coupled to a two-dimensional gas chromatography (GC ×GC) using a time-of-flight mass spectrometric detector (TOFMS) and multivariate analysis, the volatile compounds of aromatic and non-aromatic rice grains were contrasted to define some chemical markers. Fifty-one volatile compounds were selected for principal component analysis resulting in eight key-marker volatile compounds (i.e., pentanal, hexanal, 2-pentyl-furan, 2,4-nonadienal, pyridine, 1-octen-3-ol and (E)-2-octenal) as responsible for the differences between aromatic and non-aromatic rice varieties. The factors that are most likely to affect the HS-SPME efficiency for the aforementioned key-marker compounds were evaluated using a 25III−2 fractional factorial design in conjunction with multi-response optimisation. The method precision values, expressed as % of coefficient of variation (CV), were ranging from 1.91% to 26.90% for repeatability (n = 9) and 7.32% to 37.36% for intermediate precision (n = 3 × 3). Furthermore, the method was successfully applied to evaluate the volatile compounds of rice varieties from some Asian countries.

Fifteen phenolic compounds were determined in rice grains by ultrasound assisted extraction and ultra-performance liquid chromatography with photodiode array detection. Primarily, an UAE method has been developed and validated for the extraction of phenolics from rice grains. For the optimization, a Box–Behnken Design based on six factors including extraction temperature (10–70 °C), solvent composition (0–50% methanol in water), cycle (0.2–0.7 s⁻¹), ultrasound amplitude (30–70%), and solvent to sample ratio (2.5:1 to 5:1) was employed. Multi-response optimization (MRO) was performed to develop a simultaneous extraction method of 15 phenolics. The optimal UAE conditions were: extraction temperature 45 °C, time 25 min, cycle 0.4 s⁻¹, ultrasound amplitude 47%, solvent composition 80% methanol in water at pH 4.25, and sample to solvent ratio 1:5. Linearity, LODs, LOQs, precision and recovery were determined. In addition, the method was successfully applied to analyse a number of rice samples with different varieties.

Hypertension is one of the major global health issues worldwide. One of the methods can be used to treat this disease is by inhibiting the activity of angiotensin converting enzyme, an enzyme that controls the regulation of arterial blood pressure and cardiac output. Bekasam is one of the traditional fermented food made from freshwater fish (oci, Rastreliger kanaguria) with the addition of carbohydrate sources (variation concentration of palm sugar i.e. 10%; 20%; and 30%). The objective of this research was to investigate the effect of palm sugar concentration to the ACE inhibitor activity of bekasam after digestive enzyme degradation by trypsin. Hydrolysis process was evaluated by determination of the concentration of soluble protein and the degree of hydrolysis (DH) after treatmentand the ACE-inhibitory (ACEI) effect was determined by spectrophotometry method. Compared to the control without trypsin treatment (5.00±0.10 mg/ml), theconcentration of soluble protein (mg/ml)of bekasam wasincreased after trypsin hydrolysis to 16.57±0.55 at 10% of added palm sugar and then decreased to 15.38±0.18 and 10.85±0.28, at 20 and 30% of added palm sugar respectively. The degree of hydrolysis was 21.3±0.3%, 19.7±0.5% and 15.3±0.4%, for 10, 20 and 30% of palm sugar, respectively. The ACE-inhibitory activity was 87.39±0.01, 84.52±0.84, and 77.68±0.63%, for 10, 20 and 30% of added palm sugar, respectively. The results showed that the concentration of palm sugar affects the soluble protein content, degree of hydrolysis and ACEI activity after trypsin hydrolysis with the optimum sugar concentration was 10%.

There are several phenolic compounds in rice grains providing benefits for human health. The concentration of phenolic compounds in rice is strongly affected by the polishing steps during rice production. A new sensitive ultra performance liquid chromatography−ultraviolet−visible spectroscopy method with a photodiode array detection protocol has been developed and validated for the quantitation of phenolic compounds in rice grains. Several working variables and two different columns were evaluated. Finally, a less than 3 min analysis time was developed to achieve enough resolution for the simultaneous determination of the 20 most common phenolic compounds in rice. The analytical properties for the separation method produced an adequate sensitivity for all phenolic compounds in the regular range for phenolics in rice, 0.5−100 mg L−1(R2> 0.997), with high precisions for both repeatability and intermediate precisions (coefficients of variation less than 0.4 and2.5% for the retention time and area of the peaks, respectively).

The objective of our research was to investigate the properties of jack bean tempeh during fermentation with two different packaging types, banana leaves and LDPE (Low-Density Poly Ethylene) Plastic. After 24 hrs mycelia of Rhizopushasnot been formed, but it fully formed after 36 hrs fermentation for all formulated tempeh with two different packaging. The mycelia started the change to form brownish colour after 36 hrs of fermentation. Solid state fermentation (SSF) for 0, 24, 36, 48 and 60 h showed influence in different parameter e.g. total protein, the colour parameter (L, a, b, C, Hue, and ΔE) and pH during fermentation (p<0.05). Optimum condition of tempeh was chosen after 36 hrs fermentation that showed the influence of different packaging type to the lipid content and antioxidant activity (p<0.05), but no significant different to the water content, ash content, protein content, dietary fiber content and carbohydrate by the different content of tempeh (p>0.05). In the present research work, we demonstrated that different fermentation time and packaging will give influence to several physiochemical characteristics including total soluble protein, colour, and pH.

In order to decisively determine the adsorption selectivity of zirconium MOF (UiO-66) towards anionic versus cationic species, the adsorptive removal of the anionic dyes (Alizarin Red S. (ARS), Eosin (E), Fuchsin Acid (FA) and Methyl Orange (MO)) and the cationic dyes (Neutral Red (NR), Fuchsin Basic (FB), Methylene Blue (MB), and Safranine T (ST)) has been evaluated. The results clearly reveal a significant selectivity towards anionic dyes. Such an observation agrees with a plethora of reports of UiO-66 superior affinity towards other anionic species (Floride, PO₄^3 −, Diclofenac sodium, Methylchlorophenoxy-propionic acid, Phenols, CrO₄^2 −, SeO₃^2 −, and AsO₄⁻). The adsorption process of ARS as an example has been optimized using the central composite design (CCD). The resultant statistical model indicates a crucial effect of both pH and sorbent mass. The optimum conditions were determined to be initial dye concentration 11.82 mg.L^− 1, adsorbent amount 0.0248 g, shaking time of 36 min and pH 2. The adsorption process proceeds via pseudo-second order kinetics (R² = 0.999). The equilibrium data were fit to Langmuir and Tempkin models (R² = 0.999 and 0.997 respectively). The results reveal an exceptional removal for the anionic dye (Alizarin Red S.) with a record adsorption capacity of 400 mg·g^− 1. The significantly high adsorption capacity of UiO-66 towards ARS adds further evidence to the recently reported exceptional performance of MOFs in pollutants removal from water.

ABSTRACT

An analytical ultrasound-assisted extraction (UAE) technique has been optimized and validated for the extraction of tryptophan and its derivatives from rice grains. A Box–Behnken design in conjunction with a response surface methodology based on six factors and three levels was used to evaluate the effects of the studied factors prior to optimizing the UAE conditions. The significant (p < 0.05) response surface models with high coefficients of determination were fitted to the experimental data. The most significant (p < 0.0001) effect is the solvent-to-sample ratio while quadratic effects caused by temperature and solvent-to-sample ratio were of moderate importance (p < 0.05). The optimal UAE conditions were as follows: extraction time of 5 min, ultrasound amplitude of 30%, cycle of 0.7 s⁻¹, extraction temperature of 30 °C, 8% methanol in water as the extraction solvent at pH 3 and a solvent/solid ratio 5:1. The method validation ensured that appropriate values were obtained for the LOD, LOQ, precision and recovery. Furthermore, the method was successfully applied to the analysis of a number of rice samples of different varieties. It was demonstrated that this particular UAE method is an interesting tool for the determination of tryptophan and tryptophan derivatives in rice grain samples.

ABSTRACT

Some cultural practices that are carried out during the grape ripening period are associated with vine stress, including leaf removal, grape bunch removal, and vegetable cover crops. Additionally, several nitrogen and sulfur supplements have also been used directly on leaves during the last stage of the ripening period. In the work described here, five different cultural practices and the reference were applied in three replicates in the same vineyard. The evolution of tryptophan levels was evaluated from just after grape veraison until the harvest date. In some cases, certain specific treatments were also evaluated after the regular harvest date. The cultural techniques that involved the application of nitrogen led to higher levels of tryptophan at the harvest day when compared to other cultural techniques. It was also found that the application of nitrogen without sulfur had a faster effect on the level of tryptophan. It was established that a period of around 20 days is needed for the grapes to show clear differences in tryptophan levels after the application of nitrogen.

Abstract

Abstract

A Box–Behnken design was used in conjunction with multiresponse optimization based on the desirability function to carry out the simultaneous separation of tryptophan and 15 derivatives by Ultra Performance Liquid Chromatography. The gradient composition of the mobile phase and the flow rate were optimized with respect to the resolution of severely overlapping chromatographic peaks and the total run time. Two different stationary phases were evaluated (hybrid silica and a solid-core-based C₁₈ column). The methods were validated and a suitable sensitivity was found for all compounds in the concentration range 1–100 μg L^–1 (R² > 0.999). High levels of repeatability and intermediate precision (CV less than 0.25% and 1.7% on average for the retention time and the signal area, respectively) were obtained. The new method was applied to the determination tryptophan and its derivatives in black pigmented glutinous and non-glutinous rice grain samples.

ABSTRACT:

An analytical ultrasound-assisted extraction (UAE) technique has been optimized and validated for the extraction of melatonin from rice grains. A Box–Behnken design in conjunction with a response surface methodology based on six factors and three levels was used to evaluate the effects of the studied factors prior to optimizing the UAE conditions. The significant (p < 0.05) response surface models with high coefficients of determination were fitted to the experimental data. Solvent composition and extraction temperature were found to have very significant effects on the response value (p < 0.005). The optimal UAE conditions were as follows: extraction time of 10 min, ultrasound amplitude of 30%, cycle of 0.2 s−1, extraction temperature of 40 °C, 50% methanol in water as the extraction solvent at pH 3.5 and a solvent/solid ratio 2.5:1. The method validation ensured right values for linearity, LOD, LOQ, precision and recovery. Furthermore, the method was successfully applied in the analysis of a number of rice samples throughout the rice production process. Hence, it was demonstrated that this particular UAE method is an interesting tool for the determination of melatonin in rice grain samples.

ABSTRACT:

Melatonin provides a number of benefits for human health. The study reported here concerns the optimization, validation, and application of analytical pressurized liquid extraction and high-performance liquid chromatography coupled to a fluorescence detector for the determination of melatonin in rice grains. The factors that are most likely to affect the extraction efficiency were optimized with a 2IV7–2 fractional factorial design. The optimum extraction conditions were achieved by applying 70% EtOAc in MeOH at 200 °C and 200 atm for a static time of 5 min in two cycles with 50% flushing and a 60 s purge to extract a 2.5 g rice sample. The method validation ensured excellent linearity, limit of detection, limit of quantification, precision, and recovery. Furthermore, the method was applied to various rice products composed of polished, whole grain, aromatic, black, black glutinous, red, and parboiled rice. All kinds of pigmented rice grains showed high levels of melatonin (>100 μg kg –1), and the highest levels were found in red rice.

ABSTRACT:

A new microwave-assisted extraction (MAE) method has been investigated for the extraction of phenolic compounds from rice grains. The experimental conditions studied included temperature (125–175 °C), microwave power (500–1000 W), time (5–15 min), solvent (10–90% EtOAc in MeOH) and solvent-to-sample ratio (10:1 to 20:1). The extraction variables were optimised by the response surface methodology. Extraction temperature and solvent were found to have a highly significant effect on the response value (p < 0.0005) and the extraction time also had a significant effect (p < 0.05). The optimised MAE conditions were as follows: extraction temperature 185 °C, microwave power 1000 W, extraction time 20 min, solvent 100% MeOH, and solvent-to-sample ratio 10:1. The developed method had a high precision (in terms of CV: 5.3% for repeatability and 5.5% for intermediate precision). Finally, the new method was applied to real samples in order to investigate the presence of phenolic compounds in a wide variety of rice grains.

ABSTRACT:

Cultivated rice (Oryza sativa) is a global cereal crop in Southeast Asia. It serves as staple food, thus has a major contribution to the calorie intake. Furthermore, a number of antioxidant substances have been identified in rice including phenolic compounds and melatonin. The concentration and composition of these antioxidant compounds were studied on glutinous and nonglutinous grains for both pigmented and non-pigmented rice varieties. Additionally, several medium-amylose rice grains of three Indonesian varieties (IR64, umbul-umbul and pandan wangi) were also evaluated. Finding indicates that the composition of phenolic compounds are noticeably different between glutinous and nonglutinous rice grains. The level of both melatonin and total phenolics in non-glutinous rice was higher than its glutinous variety. Hence, higher amylose content exhibits relatively higher amount of antioxidant compounds.

ABSTRACT:

Rice (Oryza sativa) is the foremost cereal crop in Southeast Asia. It serves as staple food, thus has a major contribution to the calorie intake. In addition, rice contains melatonin which is beneficial for human health. It is, therefore, essential to retain this compound by appropriate rice production processes. Melatonin profile during rice production was monitored for three varieties (IR64, umbul-umbul and pandan wangi) from conventional farming and four varieties (batang lembang, pandan wangi, black and red rice) from organic farming. The effect of polishing degree on melatonin content in rice was also evaluated. Melatonin level decreased throughout rice production and then remained steady at roughly 25-40% in final product. The most influential factor was polishing which led to melatonin losses of up to 50%. The results for organically cultivated varieties were similar. However, melatonin in black rice appeared to be persistent in the matrix during rice production.

ABSTRACT:

A new microwave-assisted extraction (MAE) method has been developed for the extraction of melatonin from rice grains. The stability of melatonin under MAE conditions was studied in order to define the working range. The studied analytical conditions for the MAE were temperature (125−175 °C), microwave power (500−1000 W), time (5−15 min), solvent (10−90% EtOAc in MeOH), and ratio of solvent to sample (10:1–20:1). Extraction variables were optimized by Response Surface Methodology (RSM). Extraction temperature was found to have a highly significant effect on the response value (p < 0.0001) and the solvent and quadratic of time also had significant effects (p < 0.1). The optimized MAE conditions were as follows: extraction temperature 195 °C, microwave power 1000 W, extraction time 20 min, solvent 100% MeOH, and ratio of solvent to sample 10:1. The developed method showed high precision (in terms of CV: 4.97% for repeatability and 4.34% for intermediate precision). Finally, the new method was applied to real samples in order to investigate the presence of melatonin in a wide variety of rice grains.