Physicochemical stability and in vitro bioaccessibility of phenolic compounds and anthocyanins from Thai rice bran extracts

The Impact of Thermal Treatment and In Vitro Digestion on Antioxidant Activity and Anti-Glycation Properties of Antioxidant Crude Extract From Hot and Cold Brew Spent Coffee Ground

The ethanoic extract of hot-brew spent-coffee ground (HSCG) and cold-brew spent-coffee ground (CSCG) were prepared with ultrasound-assisted extraction and subjected to thermal processes and in vitro digestion prior to analyze the inhibition ability of advanced glycation end products (AGEs) formation, a potential risk factor for Alzheimer's disease. The obtained HSCG and CSCG extracts contained mainly chlorogenic acid derivatives, according to liquid chromatography-mass spectrometer chromatogram. The glycation process was performed by using bovine serum albumin (BSA)/ glucose system with 3 weeks incubation. In the presence of HSCG and CSCG extracts at 250 μg/mL, after thermal treatment (pasteurization and sterilization) and in vitro digestion, the glycation process through the fructosamine, AGEs, and amyloid cross β structure formation was monitored, and these extracts exhibited an anti-glycation property at early and advanced stages after pasteurization and in vitro digestion compared to no thermal treatment. However, at high temperature of sterilization, the suppress of anti-glycation property had resulted and were related with the amount of antioxidant and the ability of antioxidant scavenging as presented in a dose manner. The calculated % caffeine bio-accessibility of HSGC extracts was 65.8%, 64.8%, and 52.4% in non-thermal, pasteurized, and sterilized samples while the higher bio-accessibility was found in CSCG sample as of 67.4, 66.6, and 63.1, respectively. A high correlation of TPC values, thermal treatments and in vitro digestions with the AGEs was detected. Polyphenols and caffeine content in these extracts were found to be responsible for the AGEs and amyloid cross β structure inhibition which might potentially reduce the risk of Alzheimer's disease.

Rice bran as a potent ingredient: unveiling its potential for value-added applications

Rice bran production significantly contributes to global environmental deterioration, yet its potential remains underutilized. This review discusses the nutritional composition, bioactive compounds, health benefits, limitations, and potential application of rice bran in both food and non-food sectors. While minor variations exist between pigmented and non-pigmented rice bran, the former is abundant in phytochemicals, which offer therapeutic benefits. The primary limitations hindering rice bran's food application include rancidity, toxic heavy metals, and antinutrients. Effective stabilization is crucial to extend rice bran's shelf life. Despite these challenges, rice bran holds significant potential for value-added products. Hence, its rich composition and diverse applications underscore its importance as a valuable resource for sustainable production practices.

Physical properties and oxidative stability of mayonnaises fortified with natural deep eutectic solvent, either alone or enriched with pigmented rice bran

This article explores the novel use of natural deep eutectic solvents (NaDES) in real food by incorporating them into mayonnaise, either alone or with pigmented rice bran (RB). Results showed that NaDES-fortified mayonnaises could prevent lipid oxidation. Notably, mayonnaises with NaDES2 (betaine:sucrose:water) significantly reduced the production of lipid hydroperoxides, which was maintained to an average of 2.6 mmol LOOH/kg oil, which is 2.9 times lower than the control (7.5 mmol LOOH/kg oil), or 7.4 times lower than mayonnaise with citric acid (19.1 mmol LOOH/kg oil). NaDES2-fortified mayonnaises maintained high tocopherols levels (0.97 g/Kg oil) and reduced volatile compounds from secondary lipid oxidation. This effect may result from NaDES altering the aqueous phase properties of mayonnaise, notably by reducing water activity by ∼0.1. Finally, pre-enrichment of the NaDES phase with bioactive molecules (e.g. from pigmented RB) represents an innovative perspective to promote the health benefits of formulated foods.

Purple maize arabinoxylan could protect antioxidant compounds during digestion

Purple maize is a pigmented variety rich in antioxidants. Arabinoxylans (AX) are prebiotic compounds also found in the grain wall that can form gels. Recently, antioxidants have extensively been studied for their beneficial effects. However, these bioactive compounds do not easily reach the intestine in a stable form. These gels can protect certain compounds during in vitro digestion. This work aimed to extract the AX and simultaneously obtain the antioxidant compounds present in the external walls of the purple maize grain to produce gels with 2% and 4% AX to apply an in vitro digestion method. Popcorn maize (unpigmented) was used as a control. The amount of ferulic acid, polyphenols, and anthocyanins, and their antioxidative activity, were measured at in vitro digestion of the gels. This work highlights the ability of AX gels to enhance the potential bioavailability of antioxidant compounds including anthocyanins from purple maize after digestion.

Study of starch molecular structure-property relations provides new insight into slowly digested rice development

White rice consumption has been regarded as a potential risk factor for non-communicable diseases including obesity and type 2 diabetes. Thus, increasing attention has been paid to develop slowly digested rices with acceptable palatability. As the most abundant component of rice kernels, the fine molecular structure of starch controls not only the texture & aroma, but also the digestion properties of cooked rice. A large number of studies have been conducted to see what molecular structural features control the digestibility and palatability of cooked rice, which further could be connected to starch biosynthesis to enable rices with targeted functionalities to be chosen in non-empirical ways. Nonetheless, little progress has been made because of improper experimental designs. For example, the effects of starch fine molecular structure on cooked rice digestibility and palatability has been rarely studied within one study, resulting to various digestion results. Even for the same sample, it is hard to obtain consistent conclusions and sometimes, the results/coclusions are even controversy. In this review paper, starch fine molecular structural effects on the texture, aroma and starch digestion properties of cooked white rice were summarized followed by a detailed discussion of the relations between the fine molecular structures of amylopectin and amylose to deduce a more general conclusion of starch molecular structure-cooked rice property relations. It is expected that this review paper could provide useful information in terms of how to develop slowly digested rices with acceptable palatability.

Alginate beads loaded with rambutan extract: characterization and stability during in vitro gastrointestinal digestion

BACKGROUND

Fallen young rambutan fruit is an underrated agricultural waste which may contain several bioactive compounds. In this study, fallen young rambutan fruit was assessed regarding its phenolic contents and antioxidant activities. In order to expand its utilization, rambutan extract-loaded hydrogel beads were developed by a basic spherification technique using sodium alginate. The effect of ratios of polymer and extract and different calcium sources were evaluated. The recovery of bioactive compounds from the hydrogel beads was determined using in vitro gastrointestinal digestion models.

RESULTS

Use of 50% (v/v) ethanol yielded rambutan extract with good chemical properties. The production of hydrogel beads using a ratio of 1:3 with calcium lactate provided the highest production yield of 122.94%. The hydrogel beads developed using the ratio of 1:3 with a combination of calcium lactate and calcium chloride showed high recovery of phenolic compounds and antioxidant activity after simulated intestinal digestion, which were greater compared to unencapsulated extract.

CONCLUSION

The findings demonstrate that the ratio of wall material to rambutan extract and the calcium source influence the physical properties, chemical properties and in vitro gastrointestinal digestion stability of alginate beads. The obtained hydrogel beads may have potential for application in the food or pharmaceutical industries. © 2024 Society of Chemical Industry.

Differential Effects of In Vitro Simulated Digestion on Antioxidant Activity and Bioaccessibility of Phenolic Compounds in Purple Rice Bran Extracts

Pigmented rice varieties are abundant in phenolic compounds. Antioxidant activity and bioaccessibility of phenolic compounds are modified in the gastrointestinal tract. After in vitro simulated digestion, changes in antioxidant activity and bioaccessibility of phenolic compounds (phenolic acids, flavonoids, and anthocyanins) in purple rice brans (Hom Nil and Riceberry) were compared with undigested crude extracts. The digestion method was conducted following the INFOGEST protocol. Antioxidant activity was determined using the ferric-reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity assays. The bioaccessibility index (BI) was calculated from the ratio of digested to undigested soluble phenolic content. Overall results showed that the in vitro simulated digested rice brans had lower antioxidant activity and lower total phenolic, flavonoid, and anthocyanin contents. However, the concentration of sinapic acid was stable, while other phenolic acids (gallic, protocatechuic, vanillic, ρ-coumaric, and ferulic acids) degraded after the oral, gastric, and intestinal phases. The BI of sinapic, gallic, vanillic, and ferulic acids remained stable, and the BI of quercetin was resistant to digestion. Conversely, anthocyanins degraded during the intestinal phase. In conclusion, selective phenolic compounds are lost along the gastrointestinal tract, suggesting that controlled food delivery is of further interest.

Insights into the effect mechanism of acidic pH condition on the in vitro starch digestion of black highland barley semi-dried noodles

In this study, black highland barley semi-dried noodles (BHBSNs) were adjusted to acidic pH (5.0, 4.5, 4.0) with an acidity regulator (monosodium fumarate) for obtaining low glycemic index (GI) BHBSNs, and the changes in the in vitro starch digestion, free phenolic content, and α-amylase activity in BHBSNs were investigated. The estimated glycemic index (eGI) of BHBSNs decreased from 59.23 to 52.59, 53.89 and 53.61, respectively, as the pH was adjusted from 6.0 to 5.0, 4.5, 4.0. As the pH of BHBSNs decreased, the equilibrium hydrolysis (C∞) decreased, and kinetic coefficient (k) decreased and then increased. Compared to the control, the pH of the digestive fluid decreased during digestion with decreasing pH, and the α-amylase inhibition of BHBSNs with pH 5.0, 4.5, and 4.0 increased by 56.54 %, 75.18 %, and 107.98 %, respectively. In addition, as the pH of BHBSNs decreased, the free phenolic content and the content of released phenolics during digestion increased. Pearson correlations analysis showed that the increase in α-amylase inhibition and phenolic release during digestion induced by acidic pH was negatively correlated with the eGI and C∞ of BHBSNs. This study indicated that acidic pH condition could modulate starch digestion for preparing low GI BHBSNs.

The Effects of Encapsulation on the In Vitro Anti-Clostridial Activity of Olive Mill Wastewater Polyphenolic Extracts: A Promising Strategy to Limit Microbial Growth in Food Systems

Despite the technologies applied to food production, microbial contamination and chemical deterioration are still matters of great concern. In order to limit these phenomena, new natural approaches should be applied. In this context, the present study aimed to assess the antioxidant and anti-Clostridial effects of two different polyphenolic extracts derived from olive mill vegetation water, one liquid (LE) and one encapsulated (EE). The extracts have been preliminary characterized using Liquid Chromatography Quadrupole Time-Of Flight spectrometry. The Oxygen Radical Absorbance Capacity method was used to determine the antioxidant capacity, registering a higher value for EE compared to that for LE (3256 ± 85 and 2446 ± 13 µgTE/g, respectively). The antibacterial activity against C. perfringens, C. botulinum and C. difficile was studied by the agar well diffusion method, MIC and MBC determination and a time-kill test. The results confirm that EE and LE are able to limit microbial growth, albeit with minor effects when the phenolic compounds are encapsulated. Further studies are needed to evaluate the possible application of these extracts in food systems.

Encapsulation of Black Rice Bran Extract in a Stable Nanoemulsion: Effects of Thermal Treatment, Storage Conditions, and In Vitro Digestion

This study aimed to improve the dispersibility of phenolic compounds from black rice bran through the encapsulation process within nanoemulsion. The study focused on assessing the stability of the nanoemulsions, which were prepared using a combination of surfactants with distinct hydrophilic-lipophilic balance (HLB) values and sunflower oil under different thermal treatments and storage conditions. The study revealed a significant correlation between the mixed surfactant HLB value and the nanoemulsions properties, including average particle size, polydispersity index (PDI), and ζ-potential. Specifically, an increase in the HLB value was associated with a decrease in the initial average particle size. The encapsulated polyphenols exhibited remarkable stability over a storage period of up to 30 days at different temperatures with no significant changes observed in particle size or PDI. The study also investigated the impact of different ionic strengths (0.2, 0.5, and 1.00 mol L-1 NaCl) on the physical stability and antioxidant black rice bran extract nanoemulsion, and the results revealed that adding NaCl influenced the particle size and surface charge of the nanoemulsions. Total phenolic content and DPPH results demonstrated a significant impact of salt concentration on antioxidant properties, with varying trends observed among the HLB formulations. Furthermore, the behavior of the encapsulated extracts during digestion was examined, and their antioxidant activity was evaluated.

In vitro digestibility and hepato-protective potential of Lophatherum gracile Brongn. leave extract

Lophatherum gracile Brongn. (L. gracile) is a traditional herb for both medicine and food use, but its digestibility and hepato-protective activity is unknown. Herein we investigated the digestibility and hepato-protective potential of L. gracile leave extract (LGE) using in vitro digestion and alcohol-induced oxidative damage models. Compared to the undigested group, the content of phenolics/flavonoids and the antioxidant activity in LGE generally decreased by 9.30-19.97% in the oral and small intestine phase after digestion, while that increased by 9.96-10.17% in the gastric phase. The main phenolics/flavonoids showed promising stability during digestion and their bio-accessiblity ranged from 67.64% to 84.47%. By reducing cellular reactive oxidative species and malonaldehyde levels, LGE (0.23-0.45 mg/mL) pretreatment significantly ameliorated alcohol-induced oxidative damage in HepG2 cells (P < 0.05), and their survival rate increased from 59.23% to 67.76%. These findings suggested that L. gracile could be used for the development of hepato-protective foods.

Integration of comparative transcriptomics and WGCNA characterizes the regulation of anthocyanin biosynthesis in mung bean (Vigna radiata L.)

Mung bean is a dual-use crop widely cultivated in Southeast Asia as a food and medicine resource. The development of new functional mung bean varieties demands identifying new genes regulating anthocyanidin synthesis and investigating their molecular mechanism. In this study, we used high-throughput sequencing technology to generate transcriptome sequence of leaves, petioles, and hypocotyls for investigating the anthocyanins accumulation in common mung bean variety as well as anthocyanidin rich mung bean variety, and to elucidate their molecular mechanisms. 29 kinds of anthocyanin compounds were identified. Most of the anthocyanin components contents were significantly higher in ZL23 compare with AL12. Transcriptome analysis suggested that a total of 93 structural genes encoding the anthocyanin biosynthetic pathway and 273 regulatory genes encoding the ternary complex of MYB-bHLH-WD40 were identified, of which 26 and 78 were differentially expressed in the two varieties. Weighted gene co-expression network analysis revealed that VrMYB3 and VrMYB90 might have enhanced mung bean anthocyanin content by inducing the expression of structural genes such as PAL, 4CL, F3'5'H, LDOX, and F3'H, which was consistent with qRT-PCR results. These findings are envisaged to provide a reference for studying the molecular mechanism of anthocyanin accumulation in mung beans.

In vitro and in vivo bioaccessibility, antioxidant activity, and color of red radish anthocyanins as influenced by different drying methods

This study aims to examine the effects of various drying methods, namely vacuum freeze drying (VFD), vacuum drying (VD), hot air drying (HAD), sun drying (SD), and air-impingement jet drying (AIJD), on in vitro and in vivo bioaccessibility of red radish anthocyanins. By color parameters, VFD- and AIJD-dried red radish showed redder color to HAD-, SD-, and VD-dried red radish. SEM images of dried red radish showed multiple holes and loose interior structure. Forty-six anthocyanins were identified in red radish. Original, in vitro and in vivo digestive samples from VFD-dried red radish contained more anthocyanins and were more bioaccessibility than fresh and other dried red radishes. In vitro and in vivo research revealed that dried red radish showed weaker and stronger FRAP and ABTS·+ scavenging activities than fresh red radish. Colon content of mice had significantly higher FRAP and ABTS·+ scavenging activities than the stomach, small intestine, and cecum contents.

Influence of Storage Conditions on Stability of Phenolic Compounds and Antioxidant Activity Values in Nutraceutical Mixtures with Edible Flowers as New Dietary Supplements

This paper investigates the effects of storage conditions on the stability of phenolics and their antioxidant activities in unique nutraceutical supplements containing non-traditional cereal flakes, edible flowers, fruits, nuts, and seeds. Significant total phenolic content (TPC) of 1170-2430 mg GAE/kg and total anthocyanin content (TAC) with the values of 322-663 mg C3G/kg were determined with the highest TPC content established in free phenolic fractions. The most notable declines in TPC (by 53%), TAC (by 62%), phenolics (e.g., glycosylated anthocyanins by 35-67%), and antioxidant activity (by 25% using DPPH) were established in the presence of sunlight at 23 °C followed by the storage at 40 °C. Quercetin, rutin, peonidin, pelargonidin, p-coumaric, ellagic, and p-hydroxybenzoic acids were identified as the least stable phenolics when exposed to sunlight. Furthermore, glycosylated forms of anthocyanins demonstrated a greater stability when compared with anthocyanidins. The mixtures considerably eliminated ABTS and DPPH radicals. In all samples, water-soluble substances showed a higher antioxidant activity than lipid-soluble substances with the main contributors in the following order: delphinidin-3-glucoside (r = +0.9839) > p-coumaric > gallic > sinapic > p-hydroxybenzoic acids > delphinidin > peonidin and malvidin (r = +0.6538). Gluten-free nutraceutical mixtures M3 (containing red rice and black quinoa flakes, red and blue cornflowers, blueberries, and barberries) and M4 (containing red and black rice flakes, rose, blue cornflower, blueberries, raspberries, and barberries) were evaluated as the least stable under all storage conditions although they showed considerable phenolic concentrations. Phenolic contents and antioxidant activity of the nutraceutical mixtures were the highest at 23 °C without the presence of sunlight with the most stable M1 nutraceutical mixture (containing oat and red wheat flakes, hibiscus, lavender, blueberries, raspberries, and barberries).

Evaluation of the Potential Anti-Inflammatory Activity of Black Rice in the Framework of Celiac Disease

Inflammation and oxidative stress are two mechanisms involved in the pathogenesis of celiac disease (CD). Since the direct effect of gliadin on the intestinal epithelia is less studied, the aims of this study were the development of a specific cellular model based on the use of gliadin as a pro-inflammatory stimulus and the evaluation of the potential antioxidant and anti-inflammatory properties of extracts from different black rice in the framework of CD. The rice extracts were in vitro digested, characterized in terms of phenolic compounds and antioxidant capacity, and tested on Caco-2 cells to investigate their inhibitory effect on Reactive Oxygen Species, the NF-κB transcription and the CXC chemokines (sICAM-1, IL-8, and CXCL-10). In addition, the role of the extracts in modulating the activation of epithelial cells in CD was confirmed by applying the K562(S) agglutination test. The black rice extracts showed inhibitory effects on the production of the oxidative and the inflammatory mediators considered, with particular reference to lymphocyte-attracting CXCL-10 both before and after digestion. The presence of anthocyanins and their digestion metabolites may account for the observed anti-inflammatory activity after in vitro digestion. This work provided preliminary data supporting the use of black rice as a healthy food or ingredient of food supplements for celiacs.

Bioaccessibility and Antioxidant Activity of Polyphenols from Pigmented Barley and Wheat

Polyphenols in pigmented cereals are believed to enhance health outcomes through their antioxidant properties. This study aimed to characterise polyphenols from Hordeum vulgare (purple barley), Triticum turgidum (purple wheat) and Triticum aestivum (blue wheat) in order to evaluate their bioaccessibility and antioxidant activity. An ultra-high performance liquid chromatography mass spectrometry coupled with an online 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) system was used to identify the polyphenols and quantify their relative antioxidant levels. Simulated gastrointestinal digestion of the cereals allowed for the assessment of polyphenol bioaccessibility using benchtop assays. Between cereals, the bioaccessible phenolic content was similar following digestion, but the antioxidant activity was significantly different (purple barley > purple wheat > blue wheat; p < 0.01). Among the polyphenols identified, flavan-3-ols and anthocyanins were the least bioaccessible whereas flavones were the most bioaccessible after digestion. This study demonstrated that these pigmented cereal varieties are sources of bioaccessible polyphenols with antioxidant activity. These findings may aid in utilising these pigmented grains for the future design and development of novel functional food products with enhanced health properties.

Investigation of the Effect of Rice Bran Content on the Antioxidant Capacity and Related Molecular Conformations of Plant-Based Simulated Meat Based on Raman Spectroscopy

At present, plant-based simulated meat is attracting more and more attention as a meat substitute. This study discusses the possibility of partial substitution of rice bran (RB) for soybean protein isolate (SPI) in preparing plant-based simulated meat. RB was added to SPI at 0%, 5%, 10%, 15%, and 20% to prepare RB-SPI plant-based simulated meat by the high moisture extrusion technique. RB-SPI plant-based simulated meat revealed greater polyphenol content and preferable antioxidant capacity (DPPH radical scavenging capacity, ABTS scavenging ability, and FRAP antioxidant capacity) compared to SPI plant-based simulated meat. The aromatic amino acids (tryptophan and tyrosine) of RB-SPI plant-based simulated meats tend to be masked first, and then the hydrophobic groups are exposed as RB content increases and the polarity of the surrounding environment increases due to the change in the disulfide conformation of RB-SPI plant-based simulated meats from a stable gauche-gauche-gauche conformation to a trans-gauche-trans conformation.

In Vitro Bioaccessibility and Antioxidant Activity of Phenolic Compounds in Coffee-Fortified Yogurt

Yogurt is considered one of the most popular and healthy dairy products, and has been exploited as a delivery matrix for phenolic compounds. In this study, coffee powder was added to yogurt as a functional ingredient to produce coffee-fortified yogurt. Total phenolic compounds, antioxidant activity and individual hydroxycinnamic acids have been identified and quantified through mass spectrometry. The results from coffee-fortified yogurt were compared with fermented coffee and plain yogurt. Coffee-fortified yogurt had higher total phenolic content and antioxidant activity compared to plain yogurt. However, the total phenolic compounds found in coffee-fortified yogurt represented only 38.9% of the original content in coffee. Caffeoylquinic acids were the most abundant phenolic compounds in coffee. Fermented coffee and coffee-fortified yogurt displayed lower amounts of individual phenolic compounds with respect to coffee (69.8% and 52.4% of recovery, respectively). A protective effect of the yogurt matrix on total and individual coffee phenolic compounds has been observed after in vitro digestion, resulting in a higher bioaccessibility in comparison with digested fermented coffee. Moreover, coffee-fortified yogurt showed the highest antioxidant values after digestion. These findings clearly demonstrate that coffee-fortified yogurt can be considered a significant source of bioaccessible hydroxycinnamic acids, besides its health benefits as a fermented dairy product.

Economical and eco-friendly isolation of anthocyanins from grape pomace with higher efficiency

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Ultrasonication temperature and time were optimized with RSM.

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More anthocyanins and their derivatives were identified from grape pomace.

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Optimized method obtained nearly-two folds anthocyanin yield.

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Harmless reagents were used along all the industrial friendly steps.

Isolating anthocyanins from grape pomace, byproduct of red wine, becomes attracting for the multiple health beneficial effects of anthocyanins. Here in the ultrasound assisted anthocyanin isolation, parameters of time, ethanol concentration and pH, as well as temperature were individually optimized first. Then, surface response methodology was employed to further optimize the interactive and synergistic effect of these parameters. Optimal isolation condition was identified as the following: at the material liquid ratio of 1:15, 78.9 % of ethanol of pH 7.0 was utilized to extract at 63.8 °C for ∼48 min. Experimental yield with the optimal isolation conditions was 193.547 mg/100 g anthocyanin from grape pomace, almost twice as much as previously reported. Two more anthocyanins, delphinidin-acetylglucoside and cyanidin-coumaroylglucoside, were identified in the extract. With ethanol as the only organic solvent used, this isolation method is an economical, eco-friendly and more efficient, anthocyanin preparation method with simpler instrument setups.

Extraction, Isolation, and Purification of Value-Added Chemicals from Lignocellulosic Biomass

This review covers the operating conditions for extracting top value-added chemicals, such as levulinic acid, lactic acid, succinic acid, vanillic acid, 3-hydroxypropionic acid, xylitol, 2,5-furandicarboxylic acid, 5-hydroxymethyl furfural, chitosan, 2,3-butanediol, and xylo-oligosaccharides, from common lignocellulosic biomass. Operating principles of novel extraction methods, beyond pretreatments, such as Soxhlet extraction, ultrasound-assisted extraction, and enzymatic extraction, are also presented and reviewed. Post extraction, high-value biochemicals need to be isolated, which is achieved through a combination of one or more isolation and purification steps. The operating principles, as well as a review of isolation methods, such as membrane filtration and liquid–liquid extraction and purification using preparative chromatography, are also discussed.

Nutritional composition and antioxidant properties of the fruit of Berberis heteropoda Schrenk

Objective

This study assessed the major nutrients and antioxidant properties of Berberis heteropoda Schrenk fruits collected from the Nanshan Mountain area of Urumqi City, Xinjiang Uygur Autonomous Region, China.

Methods and materials

We assessed the basic nutrients, including amino acids, minerals, and fatty acids, and determined the total phenol, flavonoid, and anthocyanin contents of the extracts.

Results

The analytical results revealed the average water (75.22 g/100 g), total fat (0.506 g/100 g), total protein (2.55 g/100 g), ash (1.31 g/100 g), and carbohydrate (17.72 g/100 g) contents in fresh B. heteropoda fruit, with total phenol, flavonoid, and anthocyanin contents of B. heteropoda fruits at 68.55 mg gallic acid equivalents/g, 108.42 mg quercetin equivalents/g, and 19.83 mg cyanidin-3-glucoside equivalent/g, respectively. Additionally, UPLC-Q-TOF-MS^E analysis of polyphenols in B. heteropoda fruit revealed 32 compounds.

Conclusion

B. heteropoda fruits may have potential nutraceutical value and represent a potential source of nutrition and antioxidant phytochemicals in the human diet.

Effect of Soybean Protein Isolate-7s on Delphinidin-3-O-Glucoside from Purple Corn Stability and Their Interactional Characterization

Anthocyanins are abundant in purple corn and beneficial to human health. Soybean protein isolate-7s (SPI-7s) could enhance the stability of anthocyanins. The stable system of soybean protein isolate-7s and delphinidin-3-O-glucoside complex (SPI-7s-D3G) was optimized using the Box–Behnken design at pH 2.8 and pH 6.8. Under the condition of pH 2.8, SPI-7s effectively improved the sunlight-thermal stabilities of delphinidin-3-O-glucoside (D3G). The thermal degradation of D3G conformed to the first order kinetics within 100 min, the negative enthalpy value and positive entropy value indicated that interaction was caused by electrostatic interaction, and the negative Gibbs free energy value reflected a spontaneous interaction between SPI-7s and D3G. The interaction of SPI-7s-D3G was evaluated by ultraviolet visible spectroscopy, circular dichroism spectroscopy and fluorescence spectroscopy. The results showed that the maximum absorption peak was redshifted with increasing the α-helix content and decreasing the β-sheet contents, and D3G quenched the intrinsic fluorescence of SPI-7s by static quenching. There was one binding site in the SPI-7s and D3G stable system. The secondary structure of SPI-7s had changed and the complex was more stable. The stabilized SPI-7s-D3G will have broad application prospects in functional foods.

Comparative Analysis of Nutritional Components and Phytochemical Attributes of Selected Thai Rice Bran

It is important to raise awareness regarding rice's nutritional quality and health benefits in terms of enhancing rice consumption in people's daily diets. This study evaluated the proximate components and phytochemical profiles of 11 Thai rice bran varieties, 4 non-colored rice brans and 7 colored rice brans, collected from the same agricultural fields. The chemical composition (ash, fat, proteins, fiber, and gross energy) was determined using proximate analysis methods. High-performance liquid chromatography was used to analyze the γ-oryzanol, tocopherols, and anthocyanins, while gas chromatography mass spectrometry determined the free fatty compounds. The phenolic profile was determined using liquid chromatography-mass spectrometry. The results showed great variations in each parameter of the nutritional and bioactive components among different rice bran varieties. Statistical analysis was also performed correlating the results obtained from PCA to categorize the samples by their nutritional characteristics into three main groups: group A with a high content of protein and fiber, group B with a high content of fat and gross energy, and group C with low fat and energy values but high amounts of functional, active components, particularly γ-oryzanol. Anthocyanins were detected in only one sample of colored rice bran. The major free fatty acids found in rice bran samples were oleic, linoleic, and palmitic acids. Systematic assessment of the concentration of these compounds gained from this study would be helpful to the industrial sector for selecting phytochemical-rich varieties as a value-added component in nutritional products.

Starch Molecular Structural Features and Volatile Compounds Affecting the Sensory Properties of Polished Australian Wild Rice

Cooked high-amylose rices, such as Australian wild rice (AWR) varieties, have slower digestion rates, which is nutritionally advantageous, but may have inferior eating qualities. Here, a comparison is made between sensory and starch molecular fine structure properties, and volatile compounds, of polished AWR varieties and some commercial rices (CRs). Starch structural parameters for amylopectin (Ap) and amylose (Am) were obtained using fluorophore-assisted capillary electrophoresis and size-exclusion chromatography. Volatile compounds were putatively using headspace solid-phase microextraction with gas chromatography-mass spectrometry. Sensory properties were evaluated by a trained panel. AWR had a disintegration texture similar to that of Doongara rice, while AWR had a resinous, plastic aroma different from those of commercial rice varieties. Disintegration texture was affected by the amounts of Ap short chains, resinous aroma by 2-heptenal, nonadecane, 2h-pyran, tetrahydro-2-(12-pentadecynyloxy)-, and estra-1,3,5(10)-trien-17β-ol, and plastic aroma by 2-myristynoyl pantetheine, cis-7-hexadecenoic acid, and estra-1,3,5(10)-trien-17β-ol. These findings suggest that sensory properties and starch structures of AWR varieties support their potential for commercialization.

Effect of in vitro digestion on the bioaccessibility and bioactivity of phenolic compounds in fractions of Eugenia pyriformis fruit

Uvaia is a Brazilian fruit species that has great economic and nutritional potential, in addition to being a good source of compounds of biological interest. In this study, we evaluated for the first time the influence of in vitro gastrointestinal digestion on the bioaccessibility and bioactivity of phenolic compounds from two fractions of uvaia (edible and seed). It was observed that the content of total phenolic compounds was about 3 times higher in the seed (undigested extract), but reduced significantly after intestinal digestion (-50.08%). In turn, the total flavonoid content was about 5 times higher in the undigested seed extract. After intestinal digestion, the flavonoid content increased in the edible fraction (+109.49%) and decreased in the uvaia seed (-70.20%). The heatmap analysis showed that after intestinal digestion, there was an increase in the relative intensity of the flavonoids, while phenolic acids reduced their intensity. The antioxidant capacity of the undigested extract was 4-7 times greater for the seed, but decreased after intestinal digestion (-8.04-27.23%), while the antioxidant capacity of the edible fraction increased by 72.12-107.89% in this same stage of digestion. Thus, the content of phenolic compounds and antioxidant capacity were higher in the uvaia seed, and the bioaccessibility of the bioactive compounds in this fruit were dependent on the fraction and digestive phase evaluated. These results can contribute to the establishment of uvaia as a novel ingredient for preparations with functional claims.

Antioxidant Effects of Anthocyanin-Rich Riceberry™ Rice Flour Prepared Using Dielectric Barrier Discharge Plasma Technology on Iron-Induced Oxidative Stress in Mice

Redox-active iron generates reactive oxygen species that can cause oxidative organ dysfunction. Thus, the anti-oxidative systems in the body and certain dietary antioxidants, such as anthocyanins, are needed to control oxidative stress. We aimed to investigate the effects of dielectric barrier discharge (DBD) plasma technology in the preparation of Riceberry™ rice flour (PRBF) on iron-induced oxidative stress in mice. PRBF using plasma technology was rich in anthocyanins, mainly cyanidine-3-glucoside and peonidine-3-glucoside. PRBF (5 mg AE/mg) lowered WBC numbers in iron dextran (FeDex)-loaded mice and served as evidence of the reversal of erythrocyte superoxide dismutase activity, plasma total antioxidant capacity, and plasma and liver thiobarbituric acid-reactive substances in the loading mice. Consequently, the PRBF treatment was observed to be more effective than NAC treatment. PRBF would be a powerful supplementary and therapeutic antioxidant product that is understood to be more potent than NAC in ameliorating the effects of iron-induced oxidative stress.

The Potential of High-Anthocyanin Purple Rice as a Functional Ingredient in Human Health

Purple rice is recognized as a source of natural anthocyanin compounds among health-conscious consumers who employ rice as their staple food. Anthocyanin is one of the major antioxidant compounds that protect against the reactive oxygen species (ROS) that cause cellular damage in plants and animals, including humans. The physiological role of anthocyanin in plants is not fully understood, but the benefits to human health are apparent against both chronic and non-chronic diseases. This review focuses on anthocyanin synthesis and accumulation in the whole plant of purple rice, from cultivation to the processed end products. The anthocyanin content in purple rice varies due to many factors, including genotype, cultivation, and management as well as post-harvest processing. The cultivation method strongly influences anthocyanin content in rice plants; water conditions, light quantity and quality, and available nutrients in the soil are important factors, while the low stability of anthocyanins means that they can be dramatically degraded under high-temperature conditions. The application of purple rice anthocyanins has been developed in both functional food and other purposes. To maximize the benefits of purple rice to human health, understanding the factors influencing anthocyanin synthesis and accumulation during the entire process from cultivation to product development can be a path for success.