Bran Hydrolysate Research Articles

Charge mediated nano-filtration for recovering sinapic acid from a mustard bran hydrolysate

The recovery of valuable chemicals, such as sinapic acid, from enzymatic hydrolysates is essential to enabling a sustainable biorefinery. In this study, we designed a system to recover sinapic acid produced chemo-enzymatically from waste mustard bran. The process involves sequential separation, beginning with size partitioning using ultrafiltration for enzyme removal and recovery, followed by charge-mediated size partitioning via nanofiltration to isolate sinapic acid from other extracts. Four polyethersulfone (PES) ultrafiltration membranes with molecular weight cut-offs (MWCOs) of 5000 and 10 000 Da and maximum allowable working pressures (MAWPs) of 3 and 10 bar were screened for their effectiveness in removing Bovine Serum Albumin (BSA) as a model compound. Subsequently, these membranes were applied to recover the feruloyl esterase enzyme. The membrane with an MWCO of 5000 Da and an MAWP of 10 bar achieved 97.93 % enzyme recovery with a permeate flow rate of 31.4 L/h/m2 at 6 bar. Next, we evaluated the effects of zeta potential interactions on the preferential rejection of sinapic acid using various nanofiltration membranes with potentially charged surfaces, including polyimide, silicon-based thin film composite, and polypiperazine amide membranes with MWCOs ranging from 150 to 600 Da. The polypiperazine amide membrane demonstrated the highest recovery of sinapic acid, achieving 86 % recovery from a model solution and 64 % recovery from mustard bran hydrolysate. Compositional analysis of the permeate confirmed that the rejection rate (R) is influenced primarily by the pKa rather than molecular size, following the trend: sinapic acid (pKa = 4.58; 224.2 Da; R = 64.0 %), acetic acid (pKa = 4.76; 60.1 Da; R = 23.8 %), xylose (pKa = 12.15; 150.1 Da; R = 13.7 %), glucose (pKa = 12.28; 180.2 Da; R = 8.7 %), and arabinose (pKa = 12.34; 150.1 Da; R = 8.5 %). The zeta potential interactions across nanofiltration membranes enhanced sinapic acid recovery from the mustard bran hydrolysate, hence, charge mediation significantly influenced the membrane separation of these complex mixtures with varying pKa values.

S. cerevisiae ERG5DeltaNTH1DeltaAMS1Delta Construction Enhancing Stress Tolerance for Ethanol Production Increase in the Presence of Inhibitors and Mechanism Analysis based on the Comparative Transcriptomics

Saccharomyces cerevisiae is considered the most promising large-scale production strain with ethanol as the main product. The fermentation of Saccharomyces cerevisiae is generally inhibited under various stress conditions. Various inhibitors in the hydrolysate severely inhibit yeast proliferation and yeast accumulation. In this study, S. cerevisiae ERG5, NTH1, and AMS1 were knocked out to improve the yeast stress tolerance by the Clustered Regularly Interspaced Short Palindromic Repeats Cas9 (CRISPR-Cas9) technology. The result indicated that the stress tolerance of S. cerevisiae ERG5ΔNTH1ΔAMS1Δ mutant (S. cerevisiae SCENA) was remarkably improved compared with the wild-type strain. The contents of fecosterol, trehalose, and mannan in S. cerevisiae SCENA were 1.67, 1.53, and 1.47 folds compared with those in the control. The ethanol concentration in S. cerevisiae SCENA reached 16.5 g/L, which was 1.23 folds compared with the control using rice bran hydrolysate. Further, the transcriptome analysis indicated down-regulated differential expression genes (DEGs) in S. cerevisiae SCENA were mainly from cellular response to glucose, cell periphery, and plasma membrane. Up-regulated DEGs were mainly from spore wall assembly, fungal-type cell wall assembly, and ascospore wall assembly. Thus, S. cerevisiae SCENA could effectively produce ethanol using the fermentation of lignocellulosic hydrolysate in the presence of inhibitors by regulating fecosterol, trehalose, and mannan metabolisms.

Sustainable production of nutritional iron-enriched yeast from low-cost bran sources: A valuable feedstock for circular economy

Enhancing iron bioavailability through iron-enriched yeast offers a promising nutritional solution. This study explores the sustainable production of iron-enriched yeast using soybean, corn, and wheat bran hydrolysates as low-cost culture media in submerged fermentation. Culture mediums were supplemented with 15 mg L−1 of Fe+2. Iron-yeast production was successful using starchy hydrolysates due to their rich composition. Soybean bran hydrolysate achieved the highest biomass production (7.9 g L−1 dry cell), corn bran hydrolysate accomplished the largest iron incorporation (3.18 mg of iron/gram of dry cell); while supplemented wheat hydrolysate attained the greatest yield (2.58 ± 0.68 g/g). This research showed high potential on the production of iron-enriched yeast biomass from starchy hydrolysates, and the potential production of health and food products through sustainable production methods.

Antioxidant activity of fractionated pigmented Thai Hawm Gra Dang Ngah 59 rice bran hydrolysates: Pretreatment-assisted enzymatic extraction

Antioxidant activity of fractionated pigmented Thai Hawm Gra Dang Ngah 59 rice bran hydrolysates: Pretreatment-assisted enzymatic extraction

Boosting Synergistic Antioxidant and Anti-Inflammatory Properties Blending Cereal-Based Nutraceuticals Produced Using Sprouting and Hydrolysis Tools.

Nutraceuticals obtained from sprouted wheat and oat grains and processing by-products (bran and hull, respectively) naturally containing antioxidant and anti-inflammatory compounds were evaluated. The objective of this study was the development of a cereal-based nutraceutical formula combining extracts from sprouts and by-products and the exploration for potential synergetic effects in their bioactive properties. The antioxidant and anti-inflammatory capacities, glycemic index, phytic acid, and β-glucan of individual wheat bran hydrolysate (EH-WB), sprouted wheat (SW), oat hull hydrolysate (EH-OH), sprouted oat (SO), and combined ingredients (CI 1, CI 2, and CI3) were used to tailor an optimal nutraceutical formula. The three blend ingredients (CI 1, CI2, and CI3) were formulated at different ratios (EH-WB:SW:EH-OH:SO; 1:1:1:1, 2:1:2:1, and 1:2:1:2, w:w:w:w, respectively). The resulting mixtures showed total phenol (TPs) content ranging from 412.93 to 2556.66 µmol GAE 100 g-1 and antioxidant capacity values from 808.14 to 22,152.54 µmol TE 100 g-1 (ORAC) and 1914.05 to 7261.32 µmol TE 100 g-1 (ABTS•+), with Fe3+ reducing ability from 734. 02 to 8674.51 mmol reduced Fe 100 g-1 (FRAP) for the individual ingredients produced from EH-WB and EH-OH, where high antioxidant activity was observed. However, the anti-inflammatory results exhibited an interesting behavior, with a potentially synergistic effect of the individual ingredients. This effect was observed in CI2 and CI3, resulting in a higher ability to inhibit IL-6 and TNF-α than expected based on the anti-inflammatory values of their individual ingredients. Similar to the antioxidant properties, oat-based ingredients significantly contributed more to the anti-inflammatory properties of the overall mixture. This contribution is likely associated with the β-glucans and avenanthramides present in oats. To ensure the bioaccessibility of these ingredients, further studies including simulated digestion protocols would be necessary. The ingredient formulated with a 2:1 hydrolysate-to-sprout ratio was the most effective combination, reaching higher biological characteristics.

Enzymatic Activity of Fungi for Hydrolysis of Wheat Bran and Cultivation of Oleaginous Yeasts

Sustainable alternatives to petrochemical raw materials in oleochemical, laundry detergent and personal care industry need to be implemented. Presently, palm oil is the predominant cost-efficient option. While it is a renewable source, it has negative environmental and socioeconomic implications. Therefore, the request for ecologically certified and palm oil-free cleaning agents and household care products is rapidly growing, supported by concepts of waste-free biorefinery. Oleaginous yeasts are currently the most promising source for microbial lipid production. Additionally, wheat bran is a cereal milling by-product, which is available in high quantities and provides an excellent feedstock. Enzymatically generated wheat bran hydrolysate provides an excellent microbial cultivation medium for the sustainable production of high value biological additives. Indeed, wheat bran consists predominantly of lignocellulose, and therefore of cellulose, hemicellulose and lignin, which can be hydrolyzed by established enzyme systems. Currently, such enzymatic systems are mainly obtained for the market from genetically modified organisms (GMO). This represents a problem because GMO products or process components cannot be included in eco-certified household care formulations. Therefore, innovative GMO-free biotechnological processes need to be implemented, as well as the isolation of novel GMO-free hydrolase enzyme systems. Fungal strains are an interesting source for the efficient screening and isolation GMO-free hydrolases (see figure).This contribution is part of a project, which aims to use a holistic biotechnological approach to convert mill residues into customized specialty ingredients of eco-certified detergents. The project focuses on three main tasks:investigation of a microbial group of eight Ascomycete fungi,production of enzymes for hydrolysis of wheat bran, anduse of the resulting biomass hydrolysate to cultivate oleaginous yeasts.Hydrolase producing fungal strains were cultivated on different substrates to investigate their ability to generate specific enzyme systems capable of hydrolyzing wheat bran. The activity of the enzymes was qualitatively and quantitatively characterized to determine the optimal strains for the degradation of wheat bran and suited to implement a large-scale process. Supernatants of different fungal strains cultivations were tested in the hydrolysis step to compare the hydrolysis performances of differently active enzyme mixes. The biomass hydrolysate was used to cultivate lipid generating yeasts to investigate their ability to grow on the microbial cultivation medium.

Effect of addition of wheat bran hydrolysate on bread properties.

Although the addition of bran to bread makes it healthier and more functional, it brings with it some technological problems. One way to eliminate these problems is hydrothermal pretreatment of wheat bran. In this study, five different ratios (10%, 20%, 30%, 50%, and 100%) of hydrolysates from hydrothermal pretreatment of wheat bran (150°C, 30min) were substituted with dough-kneading water during dough kneading for bread making. The physical, chemical, functional, textural and important starch fractions of the bread produced were determined. The addition of hydrolysate in different amounts to the dough-kneading water resulted in similar physical properties (height, specific volume, and crust color) as the control bread. While the addition of hydrolysate decreased the hardness of the breads, it positively improved important starch fractions (increasing the amount of slowly digestible starch and decreasing the amount of rapidly digestible starch). It also increased antioxidant capacity (iron (III) reducing antioxidant power, ABTS, and DPPH (2,2-diphenyl-1-picrylhydrazyl) and reduced the starch hydrolysis index of the bread. It was shown that the hydrolysate obtained after the hydrothermal treatment of bran could be used in bread making to satisfy the demand for products preferred by consumers from both health and sensory points of view.

Impact of Time and Enzyme Concentration on Sangyod Rice Bran Hydrolysate: Phytochemicals, Antioxidants, Amino Acids, and Cytotoxicity

This study investigated the production of Sangyod rice bran hydrolysate (SYRB) from Sangyod rice, focusing on incubation times (1, 3, and 5 h) and alcalase enzyme concentrations (0, 0.7, and 1% v/v). The results demonstrated a concentration-dependent relationship: higher alcalase concentrations increased hydrolysate yield. Prolonged incubation, especially with alcalase, enhanced substrate breakdown, further increasing hydrolysate production. The degree of hydrolysis, reflecting peptide bond cleavage, depended on both incubation time and enzyme concentration, emphasizing the role of enzyme activity in efficiency. Moreover, color analysis (L*, a*, b*) and color difference (∆E) revealed intricate changes from enzymatic hydrolysis. Proximate composition analysis showed higher protein and lipid content with increased enzyme concentration and longer incubation times, whereas ash content varied with both factors. Hydrolysate powders exhibited higher moisture content than raw rice bran, indicating the impact of the hydrolysis process. The study also explored SYRB's antioxidant properties and cytotoxicity, which were sensitive to incubation time and alcalase concentration. Longer incubation increased DPPH scavenging activity, with the highest efficacy at 3 h. Meanwhile, ABTS scavenging displayed a delicate balance with alcalase concentration. The cytotoxicity study of SYRB revealed that all concentrations of SYRB were non-toxic to C2C12 cells, with cell viability values exceeding 70%.

Gamma radiation vs high pressure pretreatment on physicochemical characteristics of rice bran hydrolysate

This study investigated the effect of using gamma radiation and high-pressure processing as pretreatment, to consider the structural and amino acid composition changes in rice bran hydrolysate (RBH). The extraction yield and degree of hydrolysis of the irradiated sample were greater than those of the pressurized and control samples, which radiation at 10 kGy gave 31 % yield. Protein content of the control was the highest at 36.1 %, with 32.4 % in pressurized sample at 500 MPa. Control had the highest concentration of total and branched-chain amino acids, with a value of 25,834 mg/100g. Before and after extraction, the microstructure changed visibly and protein agglomeration can be significantly induced by applying a high-pressure. Therefore, this study showed the potential of using both pretreatment methods prior to enzymolysis extraction, with radiation producing more extract. High-pressure produced more protein content, but neither method produced any difference in amino acid content.

In-vitro-digestion of a controlled release material: composite aerated gel containing egg white protein

This study aimed to produce a healthy jelly-like product containing protein and bioactive ingredient. Egg white protein (EWP: 0, 3, 6% w/w) and sucrose (0 and 7.5% w/w) were mixed at fixed levels of konjac glucomannan, κ-carrageenan, and sodium bicarbonate in an aerated gel preparation. An interaction between EWP and sucrose significantly yielded lower gas hold-up capacity exhibiting less and small pores confirmed by SEM images. The 3% EWP with 7.5% sucrose gel was selected to further study in vitro digestion by incorporating rice bran hydrolysate (RBH) and determining phenolic compound bioaccessibility. Syneresis and gas hold-up capacity of the gel was improved due to aeration and RBH (P<0.05). Aeration also enhanced the bioaccessibility of phenolic compounds and antioxidants after digestion. Therefore, this study introduces a new food matrix which is an aerated gel containing egg white protein that exhibits high bioaccessibility following pancreatic digestion.

A remarkable enhancement in hydrogen production from Clostridium beijerinckii G117 by the co-fermentation of crude glycerol and rice bran hydrolysates

Clostridium beijerinckii G117 produces hydrogen (∼4400 mL/L) from 15 g/L of native crude glycerol (CG). While increasing the native-CG to 20–80 g/L, strain G117 rejects 34–90% of CG and fails to support a relative enhancement in hydrogen production. Subsequently, to enhance the native-CG assimilation, and hydrogen production from strain G117, various agro-residual hydrolysates (ARH), and several metal-ions have individually tested as media-supplements. Among tested, rice bran hydrolysate (RBH) and ferrous chloride (Fe2+) are selected as media-supplements. By employing RSM-based central composite design, the medium composed of 37.63 g/L CG, 3.65 g/L RBH and 1.11 mM Fe2+ is optimized which results a favorable initial redox potential (−191.0 ± 1.5 mV), higher cellular growth (6.73 ± 0.12 OD600), and 17350 ± 170 mL/L of hydrogen production from strain G117. The analysis of total-mass and electron balances suggest that this bioprocess is remarkably efficient (82–99%), and records the highest yield of hydrogen (2.27 ± 0.02 mol/mol glycerol) ever reported in literature.

Grain bran hydrolysates in the production of fruit distillates

Currently, there is an urgent need for domestic fermentation activators based on low-cost secondary raw materials. We aimed to study the effect of microbial enzyme preparations with different action on the hydrolysis of proteins and phytin of grain bran to obtain fermentation activators that could become an alternative to imported ones.
 We studied wheat and rye brans; microbial enzyme preparations with cytolytic, proteolytic, and phytase action; multi-enzyme compositions; and grain bran hydrolysates. Firstly, we determined the kinetic characteristics of enzyme preparations. Secondly, we evaluated their effectiveness in the hydrolysis of the brans. Thirdly, we developed multi-enzyme compositions. Finally, we determined the concentration of soluble forms of phosphorus and free amino acids in the hydrolysates.
 We determined optimal temperature and pH values for the enzyme preparations. The multi-enzyme compositions contributed to a high accumulation of reducing substances, water-soluble protein, and phosphorus. The concentration of free amino acids in the hydrolysates obtained under the action of the bran’s own enzymes was about 20% higher in the wheat samples, compared to the rye samples. However, when using multi-enzyme compositions in addition to the bran’s own enzymes, the concentration of free amino acids was 1.5 times higher in the rye hydrolysates, compared to the wheat hydrolysates.
 The use of multi-enzyme compositions under optimal conditions can double the content of phosphorus and free amino acids available for yeast, compared to the control. Our results can be used for further research into using grain bran hydrolysates as an alternative source of nitrogen and phosphorus nutrition for yeast at the fermentation stage of fruit distillate production.

Impact of gamma irradiation pre-treatment before subcritical water extraction on recovery yields and antioxidant properties of rice bran extract

Gamma irradiation pre-treatment of defatted rice bran was carried out before protein extraction. The extracted content included rice bran protein (RBP), rice bran protein hydrolysate (RBPH) and rice bran hydrolysate (RBH). The extraction yields and protein recovery increased with irradiation for all extracts, especially RBH, of which the yield and protein recovery increased by 21.2% and 13.8%, respectively. The total phenolic content of RBP and RBH was found to be increased in the irradiation-processed extracts. Gamma irradiation could change the structure of rice bran, increasing the release of bioactive compounds. Antioxidant activities (ABTS, DPPH, FRAP and MIC assays) increased significantly in irradiation-processed extracts. FTIR spectra confirmed that the extracts consisted of protein. The FTIR spectra of the chemical functional groups differed between RBP and RBH. In summary, gamma irradiation pre-treatment increased the extraction yield and total phenolic content and enhanced the antioxidant activity.

Supplementation with rice bran hydrolysates reduces oxidative stress and improves lipid profiles in adult dogs.

Oxidative stress is defined as an imbalance between reactive oxygen species (ROS) production and antioxidant defense mechanisms of the body. An overproduction of ROS leads to lipid and protein oxidation, injuring the cells both in normal and pathological conditions. Rice bran protein hydrolysates (RBH) has potent antioxidant, anti-inflammatory, anti-angiotensin converting enzyme (ACE) and hypolipidemic effects. Little is known, however, about the effects of RBH in dogs. The present study evaluated the antioxidative, anti-ACE and metabolic effects of RBH in adult dogs. Eighteen adult dogs were divided into 2 groups: control (n=7) and RBH supplemented groups (n=11), received a diet with the same nutritional compositions. The RBH supplemented group was fed with RBH 500 mg/kg body weight (BW) mixed with food for 30 days. BW, blood glucose, lipid profiles, liver enzymes, electrocardiography (ECG), plasma ACE activity, oxidative stress and antioxidant biomarkers were determined on day 0 and day 30 of supplementation periods. Results showed that RBH decreased oxidative stress and increased antioxidant biomarkers by significantly reducing plasma malondialdehyde (MDA) and protein carbonyl, enhanced blood glutathione (GSH) and improved the GSH redox ratio. Moreover, decreased LDL-C and increased HDL-C levels were found after RBH supplementation whereas BW, blood glucose, liver enzymes, plasma ACE activity, plasma catalase (CAT) and superoxide dismutase (SOD) activity and cardiac function were not significantly changed. These results suggest that RBH may help to lower the risk of oxidative stress and dyslipidemia in adult dogs.

Optimisation of dilute acid hydrolysis for bioethanol production from selected agricultural wastes

Firstly, yeasts were isolated from rotting orange and subjected to ethanol tolerance screening. Next, the substrates were subjected to dilute acid hydrolysis using different concentrations of HNO3 (3 %, 4 % and 5 %) at 20 % solid loading and then autoclaved at 121 oC for 30 minutes. Dilute acid optimisation yielded varying amounts of reducing sugars. The 3 %, 4 % and 5 % HNO3 solutions produced hydrolysates with the highest amounts of reducing sugars of 19.28 g/L, 16.36 g/L and 7.59 g/L from cassava peels, corn bran, and millet bran, respectively. Hydrolysate fermentation resulted in bioethanol concentrations of 7.73 g/L from cassava peels hydrolysate, 8.98 g/L from corn bran hydrolysate and 1.69 g/L from millet bran hydrolysate.

Rheological properties of dough by addition of wheat bran hydrolysates obtained at different temperatures

The functional and nutritional properties of bread could be improved by incorporating wheat bran. However, there are several disadvantages including technological, sensory and rheological associated with the use of wheat bran directly in bread processing. To eliminate these problems, wheat bran can be subjected to different pretreatments. The aim of this study was to apply hydrothermal treatment to the wheat bran at different temperatures and investigate the effect of the hydrolysates of the pretreated wheat bran on the rheological properties of dough. The hydrothermal treatment process was applied at 130–160 °C for 30 min. The amounts of reducing sugar, furfural, acetic acid and phenolic substances in the hydrolysate increased with the increase of the hydrolysis temperatures. It was determined that the addition of the hydrolysate obtained at 150 °C to dough had a positive effect on its rheological properties. It reduced the dough development time and increased the water holding capacity. However, some drawbacks started to occur in the dough's rheological properties with the use of the hydrolysates obtained at higher than 150 °C. The results of this study showed that hydrothermal treatment had the advantage of eliminating the technological and rheological problems caused by the direct addition of wheat bran.

Valorization of the Wheat Bran C5 Fraction Using Ru/ZrO2-MCM48 Catalysts

Monometallic Ru/MCM48 and Zr/MCM48 and bimetallic Ru/Zr-MCM48 and Zr/Ru-MCM48 catalysts have been synthesized and tested in the hydrogenation of wheat bran hydrolysates. Catalysts have been characterized by XRD, SAXS, TPR, TPD-NH3, TEM, and N2 adsorption/desorption at 77 K. The hemicellulose fraction has been extracted, hydrolyzed, and purified before the hydrogenation reaction. The purification step mainly consists of the extraction of the sugars in an organic phase and a back-extraction in an acid-aqueous solution. Ru/Zr-MCM48 catalyst exhibited the highest conversions of sugars in the hydrogenation of the purified wheat bran hydrolysate (PWBH), practically unchanged after 5 reaction cycles. Sugar alcohol yields were 73.2% in pentitols and 65.9% in sorbitol. The incorporation of the tetragonal ZrO2 to the MCM48 support has led to a more active and stable catalyst for the hydrogenation of PWBH. Results have shown that this incorporation must be done before the deposition of the Ru(0) phase.

Physicochemical Properties of Rice Bran Hydrolysate Prepared in a Pilot Scale Process and Its Application in Milk Tablets

The objectives of this study were to produce rice bran hydrolysate (RBH) in a pilot-scale process and determine its physicochemical properties including chemical compositions, α-amino contents, molecular weight (MW) distribution and antioxidant activities. The results found that RBH contained a crude protein of 16.14 %, α-amino contents of 51.56 mg Leucine Eq./g RBH, ABTS radical scavenging activity of 20.17 mg Trolox Eq./g RBH, and FRAP value of 5.77 mg Trolox Eq./g RBH. The major peak of MW peptides of RBH was 753 - 6,088 Da (50.81 %). RBH in various levels (0 - 2.0 %) was supplemented in milk tablets. Physicochemical properties, and sensory evaluation (9-point hedonic scale) of all milk tablets were then determined. The result indicated that the milk tablets with 2.0 % RBH (MT_2%RBH) contained higher antioxidant activities than the others, however, the overall acceptability score of all milk tablets was not significantly different (p ≥ 0.05). MT_2 %RBH was selected for further development by adding 2.0 % cocoa (MT_2%RBHC) and 2.0 % vanilla powder (MT_2%RBHV). The MT_2%RBHC containing higher antioxidant activities and sensory attributes score than the others was further selected for microbiological qualities, consumer and purchase tests (n = 300). It was found that MT_2%RBHC was accepted by 300 people, with an overall acceptability score of 7.16 (Like moderately), and its microbiological qualities, including total bacteria, total yeast and mold and Escherichia coli did not exceed the standard limits. These results suggested that RBH produced in the pilot-scale process has a potential as nutritive and antioxidative supplementation in milk tablets. HIGHLIGHTS Rice bran hydrolysate (RBH) has a potential for production in a pilot-scale process The major peak of molecular weight (MW) peptides of RBH was 753 - 6,088 Da (50.81 %) RBH has a potential as antioxidative supplementation in milk tablets Cocoa milk tablets supplemented with RBH were accepted by 300 panelists Microbiological qualities of milk tablet did not exceed the standard limits GRAPHICAL ABSTRACT

Physicochemical and antioxidative characteristics of rice bran protein extracted using subcritical water as a pretreatment and stability in a functional drink model during storage

Industrial hexane-defatted rice bran, a waste byproduct from the rice bran oil industry, was treated with subcritical water conditions followed by alkaline extraction and enzymatic hydrolysis. The extracted content included rice bran protein (RBP), rice bran protein hydrolysate (RBPH), and rice bran hydrolysate (RBH). The highest protein content, protein recovery, total phenolic content, and antioxidant activity, determined by ABTS, DPPH, FRAP, and MIC were seen in RBH. The essential amino acids index of RBH was 48%. FTIR spectra confirmed RBH consisted of protein and phenolic hydroxyl group. RBH was selected for application in the development of a functional drink, and quality was determined during storage. A functional drink supplemented with RBH contained quality protein, with high antioxidant activity and stability during storage. These results show that RBH extract has potential as a novel protein and antioxidant source that could be used in the development of functional food and drinks.

Nil-Surin Rice Bran Hydrolysates Improve Lipid Metabolism and Hepatic Steatosis by Regulating Secretion of Adipokines and Expression of Lipid-Metabolism Genes

Overconsumption of a high caloric diet is associated with metabolic disorders and a heightened risk of diabetes mellitus (DM), hepatic steatosis, and cardiovascular complications. The use of functional food has received much attention as a strategy in the prevention and treatment of metabolic disorders. This present study investigated whether Nil-Surin rice bran hydrolysates (NRH) could prevent or ameliorate the progression of metabolic disorders in rats in which insulin resistance (IR) was induced by a high fat-high fructose diet (HFFD). After 10 weeks of the HFFD, the rats showed elevated fasting blood glucose (FBG), impaired glucose tolerance, dysregulation of adipokine secretion, distorted lipid metabolism such as dyslipidemia, and increased intrahepatic fat accumulation. The IR was significantly attenuated by a daily dose of NRH (100 or 300 mg/kg/day). Doses of NRH rectified adipokine dysregulation by increasing serum adiponectin and improving hyperleptinemia. Interestingly, NRH decreased intrahepatic fat accumulation and improved dyslipidemia as shown by decreased levels of hepatic triglyceride (TG) and serum TG, total cholesterol and low-density lipoprotein cholesterol, and increased high-density lipoprotein cholesterol. In addition, a modulation of expression of lipid metabolism genes was observed: NRH prevented upregulation of the lipogenesis genes Srebf1 and Fasn. In addition, NRH enhanced the expression of fatty-acid oxidation genes, as evidenced by an increase of Ppara and Cpt1a when compared with the HFFD control group. The activities of NRH in the modulation of lipid metabolism and rectifying the dysregulation of adipokines may result in a decreased risk of DM and hepatic steatosis. Therefore, NRH may be beneficial in ameliorating metabolic disorders in the HFFD model.