Nutrients in rice bran oil and their nutritional functions: a review.

Rice is an important food crop throughout the world. Rice bran, the outer layer of rice grain, is a by-product generated during the rice milling process. Rice bran oil (RBO) is extracted from rice bran and has also become increasingly popular. RBO is considered to be one of the healthiest cooking oils due to its balanced proportion of fatty acids, as well as high content of γ-oryzanol together with phytosterols, vitamin E, wax ester, trace and macro elements, carotenoids, and phenolics. The existence of these compounds provides RBO with various functions, including hypotensive and hypolipidemic functions, antioxidant, anticancer, and immunomodulatory functions, antidiabetic function, anti-inflammatory and anti-allergenic functions, hepatoprotective activity function, and in preventing neurological diseases. Recently, research on the nutrients in RBO focused on the detection of nutrients, functions, and processing methods. However, the processing and utilization of rice bran remain sufficiently ineffective, and the processing steps will also affect the nutrients in RBO to different degrees. Therefore, this review focuses on the contents and nutritional functions of different nutrients in RBO and the possible effects of processing methods on nutrients.

Co-bioaugmentation with microalgae and probiotic bacteria: Sustainable solutions for upcycling of aquaculture wastewater and agricultural residues into microbial-rice bran complexes.

Aquaculture farming generates a significant amount of wastewater, which has prompted the development of creative bioprocesses to improve wastewater treatment and bioresource recovery. One promising method of achieving these aims is to directly recycle pollutants into microbe-rice bran complexes, which is an economical and efficient technique for wastewater treatment that uses synergetic interactions between algae and bacteria. This study explores novel bioaugmentation as a promising strategy for efficiently forming microbial-rice bran complexes in unsterilized aquaculture wastewater enriched with agricultural residues (molasses and rice bran). Results found that rice bran serves a dual role, acting as both an alternative nutrient source and a biomass support for microalgae and bacteria. Co-bioaugmentation, involving the addition of probiotic bacteria (Bacillus syntrophic consortia) and microalgae consortiums (Tetradesmus dimorphus and Chlorella sp.) to an existing microbial community, led to a remarkable 5-fold increase in microbial-rice bran complex yields compared to the non-bioaugmentation approach. This method provided the most compact biofloc structure (0.50 g/L) and a large particle diameter (404 µm). Co-bioaugmentation significantly boosts the synthesis of extracellular polymeric substances, comprising proteins at 6.5 g/L and polysaccharides at 0.28 g/L. Chlorophyta, comprising 80% of the total algal phylum, and Proteobacteria, comprising 51% of the total bacterial phylum, are emerging as dominant species. These microorganisms play a crucial role in waste and wastewater treatment, as well as in the formation of microbial-rice bran complexes that could serve as an alternative aquaculture feed. This approach prompted changes in both microbial community structure and nutrient cycling processes, as well as water quality. These findings provide valuable insights into the transformative effects of bioaugmentation on the development of microbial-rice bran complexes, offering potential applications in bioprocesses for waste and wastewater management.

Development of rice bran-derived nanoparticles with excellent anti-cancer activity and their application for peritoneal dissemination.

BACKGROUND: Rice bran a by-product of the rice milling process is currently underutilized. Recent studies have shown that plant-derived nanoparticles (pdNPs) can be mass-produced at a low cost and exhibit biological and therapeutic activities. Rice bran contains various anti-cancer compounds, including γ-oryzanol and γ-tocotrienol, and rice bran-derived nanoparticles (rbNPs) can be employed as novel therapeutic agents for cancer treatment. RESULTS: Koshihikari rice bran was suspended in water, and the suspension was centrifuged and filtered through a 0.45-µm-pore size syringe filter. The filtrate was ultracentrifuged, and the precipitates were suspended to obtain rbNPs. The rbNPs were negatively charged exosome-like nanoparticles with an average diameter of approximately 130 nm. The rbNPs exhibited cytotoxic activities against cancer cells but not against normal cells. The cytotoxic activity of rbNPs to murine colon adenocarcinoma colon26 cells was significantly greater than DOXIL® or other pdNPs. The rbNPs induced cell cycle arrest and apoptosis, and reduced the expression of proliferative proteins, including ß-catenin and cyclin D1. Intraperitoneal injections of rbNPs into mice bearing peritoneal dissemination of colon26 cells significantly suppressed tumor growth with no significant adverse effects. CONCLUSION: These results indicated that rbNPs are promising nanoparticles, hold significant potential for anti-cancer applications, and are expected to play a vital role in cancer treatment.

Hypolipidemic Effect of Rice Bran Oil Extract Tocotrienol in High-Fat Diet-Induced Hyperlipidemia Zebrafish (Danio Rerio) Induced by High-Fat Diet.

In recent years, the potent influence of tocotrienol (T3) on diminishing blood glucose and lipid concentrations in both Mus musculus (rats) and Homo sapiens (humans) has been established. However, the comprehensive exploration of tocotrienol's hypolipidemic impact and the corresponding mechanisms in aquatic species remains inadequate. In this study, we established a zebrafish model of a type 2 diabetes mellitus (T2DM) model through high-fat diet administration to zebrafish. In the T2DM zebrafish, the thickness of ocular vascular walls significantly increased compared to the control group, which was mitigated after treatment with T3. Additionally, our findings demonstrate the regulatory effect of T3 on lipid metabolism, leading to the reduced synthesis and storage of adipose tissue in zebrafish. We validated the expression patterns of genes relevant to these processes using RT-qPCR. In the T2DM model, there was an almost two-fold upregulation in pparγ and cyp7a1 mRNA levels, coupled with a significant downregulation in cpt1a mRNA (p < 0.01) compared to the control group. The ELISA revealed that the protein expression levels of Pparγ and Rxrα exhibited a two-fold elevation in the T2DM group relative to the control. In the T3-treated group, Pparγ and Rxrα protein expression levels consistently exhibited a two-fold decrease compared to the model group. Lipid metabolomics showed that T3 could affect the metabolic pathways of zebrafish lipid regulation, including lipid synthesis and decomposition. We provided experimental evidence that T3 could mitigate lipid accumulation in our zebrafish T2DM model. Elucidating the lipid-lowering effects of T3 could help to minimize the detrimental impacts of overfeeding in aquaculture.

Preparation and characterization of microcrystalline cellulose from rice bran.

BACKGROUND: Rice bran, a by-product of rice processing, has not been fully utilized except for the small amount used for raising animals. The raw material source requirements of microcrystalline cellulose are becoming increasingly extensive. However, the characteristics of preparing microcrystalline cellulose from rice bran have not been reported, which limits the application of rice bran. RESULTS: Microcrystalline cellulose was obtained from rice bran by alkali treatment, delignification, bleaching and acid hydrolysis. The morphology, particle size distribution, degree of polymerization, crystallinity, and thermal stability of rice bran microcrystalline cellulose were analyzed. The chemical compositions, scanning electron microscopy and Fourier-transform infrared analysis for rice bran microcrystalline cellulose showed that the lignin and hemicellulose were successfully removed from the rice bran fiber matrix. The morphology of rice bran microcrystalline cellulose was shown to be of a short rod-shaped porous structure with an average diameter of 65.3 µm. The polymerization degree of rice bran microcrystalline cellulose was 150. The X-ray diffraction pattern of rice bran microcrystalline cellulose showed the characteristic peak of natural cellulose (type I), and its crystallization index was 71%. The rice bran microcrystalline cellulose may be used in biological composites with temperatures between 150 °C and 250 °C. CONCLUSION: These results suggest the feasibility of using rice bran as a low-price source of microcrystalline cellulose. © 2024 Society of Chemical Industry.

Combination of fermentation and enzymolysis enhances bioactive components and function of de-oiled rice bran.

BACKGROUND: De-oiled rice bran (DORB), a substantial yet underutilized byproduct of rice processing, boasts a rich composition of active ingredients but suffers from limited application. Previous studies have indicated that enzymatic or fermentation treatments enhanced these active components. In this study, lactobacilli and complex enzymes were employed to co-treat DORB, involving the determination of the changes in active components and functionalities of DORB extract (DORBE) before and after this treatment. RESULTS: Following fermentation-enzymolysis, the total phenol and total flavonoid contents in DORBE were significantly increased by 43.59% and 55.10%, reaching 19.66 and 34.34 g kg-1, respectively. Antioxidant tests in vitro demonstrated that the co-treatment enhanced the scavenging activities of DPPH, hydroxyl and ABTS radicals. Porcine intestinal epithelial cell experiments revealed that, compared to DORBE, the fermentation and enzymolysis DORBE (FDORBE) exhibited significantly improved cell viability and catalase activity as well as scavenging capacity for reactive oxygen species and malondialdehyde after induction by H2O2. Furthermore, FDORBE restored the decreased mRNA expression levels of Nrf2, HO-1 and NQO1 in the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway stimulated by H2O2. CONCLUSION: Fermentation-enzymolysis co-treatment increases the contents of bioactive components of DORBE and enhances its antioxidant capacity, leading to a better protection against intestinal disorders induced by oxidative stress, suggesting that this co-treatment is a rational and effective strategy to increase the value of grains and promotes the use of DORB as a functional feed in animal production. © 2024 Society of Chemical Industry.

Preparation and functional properties of rice bran globulin-chitooligosaccharide-quercetin-resveratrol covalent complex.

BACKGROUND: As the major protein (approximately 36%) in rice bran, globulin exhibits excellent foaming and emulsifying properties, endowing its useful application as a foaming and emulsifying agent in the food industry. However, the low water solubility restricts its commercial potential in industrial applications. The present study aimed to improve this protein's processing and functional properties. RESULTS: A novel covalent complex was fabricated by a combination of the Maillard reaction and alkaline oxidation using rice bran globulin (RBG), chitooligosaccharide (C), quercetin (Que) and resveratrol (Res). The Maillard reaction improved the solubility, emulsifying and foaming properties of RBG. The resultant glycosylated protein was covalently bonded with quercetin and resveratrol to form a (RBG-C)-Que-Res complex. (RBG-C)-Que-Res exhibited higher thermal stability and antioxidant ability than the native protein, binary globulin-chitooligosaccharide or ternary globulin-chitooligosaccharide-polyphenol (only containing quercetin or resveratrol) conjugates. (RBG-C)-Que-Res exerted better cytoprotection against the generation of malondialdehyde and reactive oxygen species in HepG2 cells, which was associated with increased activities of antioxidative enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) through upregulated genes SOD1, CAT, GPX1 (i.e. gene for glutathione peroxidase-1), GCLM (i.e. gene for glutamate cysteine ligase modifier subunit), SLC1A11 (i.e. gene for solute carrier family 7, member 11) and SRXN1 (i.e. gene for sulfiredoxin-1). The anti-apoptotic effect of (RBG-C)-Que-Res was confirmed by the downregulation of caspase-3 and p53 and the upregulation of B-cell lymphoma-2 gene expression. CONCLUSION: The present study highlights the potential of (RBG-C)-Que-Res conjugates as functional ingredients in healthy foods. © 2024 Society of Chemical Industry.

Unlocking the potential of rice bran oil body as fat replacement in cookies: single and double crosslinked binary emulsion-filled gels based on lutein-loaded rice bran oil body emulsion.

BACKGROUND: Rice bran oil body is rich in nutritional value, which is a byproduct of rice processing. The aim of this study is to develop a novel emulsion-filled gel with lutein-loaded rice bran oil body and investigate its functionality as a fat replacer in cookies. The effects of incorporating structured oil body in the form of emulsion-filled gel instead of butter in cookies with a ratio of 0, 10, 20 and 50 wt% formulation were determined by measuring appearance, texture, thermodynamic properties, moisture distribution and microstructure. RESULTS: The results demonstrated the relationship between geometry, moisture and structure. The 20 wt% emulsion-filled gel substitution ratio yielded mobility and distribution abilities of melted fat and sugar in the cookies that were closest to those of butter. The addition of emulsion-filled gel increased the L* value and decreased the a* value, while the b* value of the cookie increased due to the advanced delivery of lutein by oil body. By controlling the addition ratio, the texture of the cookies can be adjusted. Starch granules were separated due to colloidal particles, reducing saturated fat content and decreasing cookie gelatinization enthalpy. The fat coating on starch particles enhanced the binding capacity of free water, improving air entrapment and forming a constrained gluten network structure. CONCLUSION: These findings provide a theoretical basis for rice bran oil body as a novel substitute for butter in the development of healthy, high-quality cookies. © 2024 Society of Chemical Industry.

Oxidised rice bran oil induced oxidative stress and apoptosis in IPEC-J2 cells via the Nrf2 signalling pathway.

Rice bran oil is a type of rice oil made by leaching or pressing during rice processing and has a high absorption rate after consumption. When oxidative rancidity occurs, it may cause oxidative stress (OS) and affect intestinal function. Meanwhile, the toxic effects of oxidised rice bran oil have been less well studied in pigs. Therefore, the IPEC-J2 cells model was chosen to explore the regulatory mechanisms of oxidised rice bran oil on OS and apoptosis. Oxidised rice bran oil extract treatment (OR) significantly decreased the viability of IPEC-J2 cells. The results showed that OR significantly elevated apoptosis and reactive oxygen species levels and promoted the expression of pro-apoptotic gene Caspase-3 messenger RNA levels. The activation of Nrf2 signalling pathway by OR decreased the cellular antioxidant capacity. This was further evidenced by the expression of kelch-like ECH-associated protein 1, heme oxygenase 1, NADH: quinone oxidoreductase 1, superoxide dismutase 2 and heat shock 70 kDa protein genes and proteins were all downregulated. In conclusion, our results suggested that oxidised rice bran oil induced damage in IPEC-J2 cells through the Nrf2 signalling pathway.

Low temperature desolventization: effect on physico-chemical, functional and structural properties of rice bran protein.

De-oiled rice bran is a good source of high-quality protein; however, the current practice of desolventization at high temperature (110-120 °C) denatures the protein, making its extraction difficult and uneconomical. The present study aims to investigate the effect of low temperature desolventization of de-oiled rice bran (LTDRB) on extraction, yield, and purity of protein and its comparison with protein obtained from high temperature desolventized de-oiled rice bran (HTDRB). The optimal conditions for preparation of protein from LTDRB were: extraction pH 11.00, extraction duration 52 min, and extraction temperature 58 °C resulting in an extraction efficiency, yield, and purity of 54.0, 7.23, and 78.70%, respectively. The LTDRB showed a positive impact on the color, solubility, foaming capacity and stability of protein whereas the absorption and emulsification properties were better for HTDRB protein. Significant decrease in enthalpy (ΔH) for denaturation was observed for LTDRB protein as compared to HTDRB protein. Scanning electron microscopy analysis revealed that HTDRB protein was more compact than LTDRB protein. LTDRB protein had smaller particle size distribution than HTDRB. Study suggested that low temperature desolventization can result in higher protein extraction with better physico-chemical, structural, and functional properties of protein obtained from DRB.

Extraction of Heat-Stabilised Defatted Rice Bran Protein by Solid-State Fermentation Using Heterofermentative Microbes from Traditional Asian Starters.

Research background: Heat-stabilised defatted rice bran (HSDRB) is a primary by-product of rice bran oil extraction industry and a nutritious source of protein. However, despite the unique nutritional profile of rice bran protein, the protein-rich by-product, HSDRB is underutilised as a low-value animal feed. Research on protein extraction from HSDRB by enzymatic hydrolysis has attracted the attention of numerous scientists. However, a cost-effective extraction method is required to mitigate the high costs associated with the use of enzymes. Therefore, we have presented an alternative economical and natural approach for protein extraction from HSDRB by solid-state fermentation (SSF) with heterofermentative microbes. Experimental approach: SSF of HSDRB with two types of traditional Asian fermentation starters, namely loog-pang and koji, were evaluated for enzyme production and their efficacy in extracting proteins from HSDRB. For this purpose, HSDRB fermentation was carried out for 0, 12, 24, 48, 72 and 96 h followed by 24-hour hydrolysis to evaluate the extracted rice bran protein. In addition, microbiome diversity in the fermentation starters was also determined by metagenomic sequencing of 16S rRNA and internal transcribed spacer to identify bacteria and fungi, respectively. Results and conclusions: The microbial community in the fermentation starters showed the dominance of lactic acid bacteria (LAB) such as Bacillus subtilis in loog-pang and Streptococcus lutetiensis, Bacillus pumilus, Lactococcus cremoris, Lactococcus garvieae and Pediococcus pentosaceus in koji, while yeast species Saccharomycopsis fibuligera and Saccharomyces cerevisiae dominated the fungal diversity in loog-pang and koji starters, respectively. The results suggest that loog-pang and koji can produce cellulase, neutral and acid proteases during fermentation. Despite the discrepancy in their microbial diversity and the enzyme activity during SSF, both starters could effectively increase protein extraction from HSDRB. A positive relationship between the SSF duration and extracted protein was observed. During SSF with loog-pang and koji after 72 h followed by 24-hour hydrolysis, 65.66 and 66.67 % protein was extracted from HSDRB, respectively. The amino acid analysis of the protein hydrolysate produced by the non-fermented and fermented methods showed no difference and had an abundance of glutamic and aspartic acids, leucine, arginine, alanine and glycine amino acids, which accounted for approx. 58 % of the total amino acids. Novelty and scientific contribution: Loog-pang and koji (traditional Thai and Japanese fermentation starters, respectively) were found to be effective in extracting proteins from HSDRB by SSF although they are inexpensive microbial enzyme sources. Future research aimed at scaling up HSDRB protein extraction for usage in industrial applications can draw on our results.

Utilization and Evaluation of Rice Bran and Rice Bran Wax as a Tablet Lubricant.

The rice bran and rice bran wax of the KJ CMU107 rice strain were investigated as potential tablet lubricants in a directly compressed tablet formulation. Stabilized full-fatted rice bran (sFFRB), stabilized defatted rice bran (sDFRB), and rice bran wax (RBW) extracted and purified from crude rice bran oil (cRBO) were tested. Two commercial lubricants, including magnesium stearate (MGS) and hydrogenated cottonseed oil (HVO), were employed as the standards in the formulated mixtures, which contained spray-dried rice starch (SDRS) as a diluent. The tableting was carried out for each formulation, and the obtained tablets were physically and mechanically evaluated. Among the parameters investigated were the general appearance, ejection force, weight variation, hardness, friability, and disintegration time. The powder flow was also determined for each formulation. The results showed that the tablet ejection forces for all the lubricated formulations (58-259 N) were significantly lower than that of the non-lubricated control formulation (349 N). The use of sFFRB as a lubricant at 0.5-2.0% w/w could lower the ejection force up to 78%, but the hardness reduced so drastically that the formulations failed the friability test due to the chipping of the tablets' edges. Moreover, sDFRB performed significantly better as the use at 0.5-1.0% w/w in the formulation helped to lower the ejection forces by up to 80% while maintaining the changes in the tablet hardness within 10%. RBW functioned effectively as a tablet lubricant at a concentration of 0.5% w/w, yielding tablets with good strength comparable to standard HVO lubricant while helping to reduce the ejection force by 82%. In formulations with good lubrication, i.e., friability < 1%, the powder flow was improved, and the tablet disintegration times were within the same range as the control and HVO formulations. In conclusion, sDFRB displayed a lubricant property at concentrations between 0.5 and 1.0% w/w, with slightly negative effects on the tablet hardness. RBW from KJ CMU107 rice was an effective tablet lubricant at 0.5% w/w, with no effect on tablet hardness. Both materials can be further developed for use as commercial lubricants in direct compression.

Lipidomics analysis unveils the dynamic alterations of lipid degradation in rice bran during storage.

Recent explorations into rice bran oil (RBO) have highlighted its potential, owing to an advantageous fatty acid profile in the context of health and nutrition. Despite this, the susceptibility of rice bran lipids to oxidative degradation during storage remains a critical concern. This study focuses on the evolution of lipid degradation in RBO during storage, examining the increase in free fatty acids (FFAs), the formation of oxylipids, and the generation of volatile secondary oxidation products. Our findings reveal a substantial rise in FFA levels, from 109.55 to 354.06 mg/g, after 14 days of storage, highlighting significant lipid deterioration. Notably, key oxylipids, including 9,10-EpOME, 12,13(9,10)-DiHOME, and 13-oxoODE, were identified, with a demonstrated positive correlation between total oxylipids and free polyunsaturated fatty acids (PUFAs), specifically linoleic acid (LA) and α-linolenic acid (ALA). Furthermore, the study provides a detailed analysis of primary volatile secondary oxidation products. The insights gained from this study not only sheds light on the underlying mechanisms of lipid rancidity in rice bran but also offers significant implications for extending the shelf life and preserving the nutritional quality of RBO, aligning with the increasing global interest in this high-quality oil.

The synergistic effects of rice bran rancidity and dephenolization on digestive properties of rice bran protein.

Both rice bran (RB) rancidity and dephenolization could affect the structural characteristics and phenolics composition of rice bran protein (RBP), thereby affecting RBP digestibility. The synergistic effects of RB rancidity and dephenolization on RBP digestibility were investigated. Excessive RB rancidity (RB stored for 10 d) and non-dephenolization reduced RBP digestibility, while moderate RB rancidity (RB stored for 1 d) combined with dephenolization improved RBP digestibility to a maximum of 74.19%. Dephenolization reduced the antioxidant capacities of RBP digestive products. The digestibility of non-dephenolized RBP (NDRBP) was significantly (P < 0.05) related with its carbonyl content, surface hydrophobicity, and ζ-potential. The digestibility of dephenolized RBP (DRBP) was significantly related with its ß-sheet structure content, surface hydrophobicity, ζ-potential, and average particle size. Overall, moderate RB rancidity combined with dephenolization enhanced RBP digestibility by reducing the non-competitive inhibition of endogenous phenolics on protease and regulating the spatial structural characteristics of RBP.

Protein oxidation affected the encapsulation properties of rice bran protein fibril-high internal phase pickering emulsions: Enhanced stability and bioaccessibility of ß-carotene.

Rice bran protein fibril (RBPF)-high internal phase Pickering emulsions (HIPPEs) loaded with ß-carotene (CE) were constructed to enhance stability and bioavailability of CE. Rice bran (RB) protein with varying oxidation degrees was extracted from RB with varying storage period (0-10 days) to prepare RBPF by acid-heating (90 °C, 2-12 h) to stabilize HIPPEs. The influence of protein oxidation on the encapsulation properties of RBPF-HIPPEs was studied. The results showed that CE-HIPPEs could be stably stored for 56 days at 25 °C. When RB storage time was the same, the average particle size, lipid hydroperoxide content, and malondialdehyde content of CE-HIPPEs and the CE degradation rate initially fell, and then grew as the acid-heating time prolonged, while the ζ-potential value, viscosity, viscoelasticity, free fatty acid (FFA) release rate, and bioaccessibility first rose, and subsequently fell. When acid-heating time of RBPF was the same, the average particle size, lipid hydroperoxide content, and malondialdehyde content of CE-HIPPEs initially fell, and subsequently increased with RB storage time extended, while the ζ-potential value, viscosity, viscoelasticity, FFA release rate, and bioaccessibility initially increased, and then decreased. Overall, Moderate oxidation and moderate acid-heating enhanced the stability as well as rheological properties of CE-HIPPEs, thus improving the stability and bioaccessibility of CE. This study offered a new insight into the delivery of bioactive substances by protein fibril aggregates-based HIPPEs.

Effect of rice bran extract on in vitro rumen fermentation and methane production.

This study was done to investigate which components of rice bran (RB) are involved in the inhibition of methanogenesis by fractionating the rice bran and adding it to a rumen in vitro culture system. The RB extract obtained using ethanol and water was screened in an in vitro fermentation system. The experimental treatment conditions were as follows: a control group containing a substrate without supplements; substrates with 0.06 g of RB; 0.6 mL of ethanol; 0.6 mL of distilled water (DW); 0.6 mL of ethanol-soluble fraction (ESF); 0.06 g of ethanol-insoluble rice bran (EIRB); 0.6 mL of water-soluble fraction (WSF); and 0.06 g of water-insoluble rice bran (WIRB). Based on the result of the analysis, the addition of ESF significantly decreased CH4 and CH4 /g dry matter digested, methanogen population (p < 0.05), while gas and dry matter digestibility (DMD) were comparable with the control group. Total short-chain fatty acid (SCFA), and proportion of propionate were reduced, and the proportion of butyrate was increased by the addition of ethanol and ESF (p < 0.05). This result suggests that the supplementation of 10% ESF can substantially reduce methane production in vitro without a negative effect on substrate digestibility.

Evaluation of flavor substances of rice bran kvass based on electronic nose and gas chromatography-mass spectrometry.

In this paper, the electronic nose (E-nose) and headspace-solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) were used to analyze the volatiles of rice bran kvass (RBK) with the reference of Qiulin kvass (QLK). Meanwhile, the flavor amino acids of RBK before and after fermentation were determined. The results showed that the kinds of kvass remained consistent in terms of the overall category of volatiles while there were differences in content between them (p < 0.05). A total of 35 volatile compounds, mainly including esters, alcohols, phenols, aldehydes, and acids, were identified by GC-MS in the two kinds of kvass. In addition, the total essential amino acid content and the total sweet amino acid content of RBK increased significantly (p < 0.05) after fermentation. RBK contains both the main flavor of kvass and its own unique characteristics, making it a new member of the Kvass family.

Gamma-Aminobutyric Acid in Rice Bran Extract Exerts Antistress Effects in Mouse Models with Depressive-Like Behaviors.

Various neurotransmitters are involved in regulating stress systems. In this study, we investigated the effects of gamma-aminobutyric acid-rich rice bran extract (GRBe) in mice stressed by forced swimming and tail suspension tests. Four weeks of oral administration of GRBe (500-2000 mg/kg) reduced the levels of dopamine and corticosterone in the blood and brain while increasing serotonin levels. GRBe was involved not only in stress but also in regulating sleep and obesity-related genes. Modern society experiences diverse and tense lives because of urbanization and informatization, which cause excessive stress due to complicated interpersonal relationships, heavy work burden, and fatigue from the organized society. High levels of stress cause psychological instability and disrupt the balance in the autonomic nervous system, which maintains the body's equilibrium, resulting in cardiovascular and cerebrovascular diseases, hormonal imbalances, and sleep disorders. Therefore, our results suggest that GRBe is a useful substance that can relieve tension by ultimately influencing a depressive-like state by lowering the levels of neuronal substances, hormones, and cytokines involved in stress and sleep disorders.

Self-assembly embedding of curcumin by alkylated rice bran protein.

Lysine-rich rice bran protein (RBP) can be used as raw material for alkylation modification to improve the self-assembly performance of protein. The results of 1H NMR, degree of alkylation, and DSC analysis showed that the alkyl chain was successfully attached to the RBP. The surface hydrophobicity and absolute ζ-potential increased. The three-dimensional structure of the alkylated RBP (ARBP) become more porous and ARBP-2 was selected as the material for embedding curcumin. The XRD results revealed that curcumin induced self-aggregation of ARBP-2 and the inclusion of curcumin was attained. The maximum encapsulation efficiency of curcumin was 82.67 % and the maximum loading amount was 171.37 g/100 g RBP. The results of atomic force microscopy (AFM), particle size, and polydispersity index (PDI) analyses revealed that the particles in the system were aggregated after curcumin was added. Curcumin was well protected by encapsulation in the self-assembled particles. Thus, this study provides a new strategy for the embedding and delivery of curcumin.

Kinetic parameter for scale-up and γ-oryzanol content of rice bran oil as antioxidant: Comparison of maceration, ultrasonication, pneumatic press extraction.

Rice bran oil is one of oryzanol source oils. Oryzanol is an antioxidant compound that is related to the absorption of cholesterol, and is used in hyperlipidemia treatment and menopause problems. RBO extraction, purification and its γ-oryzanol content have been carefully reviewed. The quality and concentration of γ-oryzanol depend on the extraction process and purification. In selecting the extraction method to obtain the highest oryzanol content, in addition to comparing the concentration of oryzanol obtained and it can also be done by comparing the extraction kinetics parameters. Modeling according to physical or empirical kinetics can contribute in increasing the result of extraction. This study aims to determine the highest oryzanol content in rice bran oil, comparing several extraction methods and studies of rice bran oil extraction kinetic is necessary for scale up purposes. In this study is conducted Rice Bran Oil Extraction with n-Hexane solvent using several different methods, such as maceration, ultrasonication, and pneumatic press extractions. Independent variable that is used is the extraction time and yield as dependent variable. The study shows that the best extraction method to get the highest yield is 10.34 % by ultrasonicator and oryzanol content is 5.09 mg/g by a pneumatic press machine. According to kinetic parameter k2 is 0.001546, Cs is 0.0589, and h is 0.4707, R2 = 0.9715 obtained from extraction using ultrasonicator.