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.

α-Tocotrienol in rice bran enhances steroidogenesis in mouse Leydig cell via increased gene expression of steroidogenic acute regulatory protein and induction of its mitochondrial translocation.

Rice is a staple food in the Asian region and one of the world's major energy sources. Testosterone is a steroid hormone that maintains physical, sexual, and cognitive ability, and its decline causes health problems like late-onset hypogonadism. Evaluation of various grain extracts showed rice bran to stimulate testosterone secretion from Leydig model cells. α-Tocotrienol was found as a bioactive compound in rice bran, and mechanistic analysis showed the stimulation of steroid hormone synthesis through enhanced gene expression of steroidogenic acute regulatory protein as well as inducing mitochondrial localization of the protein. Preliminary study showed an increasing trend in serum testosterone levels in mice by oral intake of α-tocotrienol. These results suggest that α-tocotrienol intake may be effective in preventing symptoms caused by low testosterone levels.

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.

Anti-skin ageing activities of rice (Oryza sativa) bran soft and hard waxes in cultured skin cells.

OBJECTIVE: Rice (Oryza sativa) bran waxes, the by-products of rice bran oil manufacturing, are widely used as inactive components in several preparations. Nevertheless, the function of rice bran waxes against skin ageing has never been reported. This study aimed to investigate thermal property and fatty acid profile of rice bran waxes, including rice bran soft (RBS) and hard (RBH) waxes, and the activities against skin ageing in cultured skin cells. METHODS: Thermal property and fatty acid profile of rice bran waxes were analysed by differential scanning calorimetry and gas chromatography-mass spectrometry, respectively. The cytotoxicity assay of waxes was performed in B16F10 melanoma cells, human skin fibroblasts and co-culture cells of HaCaT cells and human skin fibroblasts. The non-cytotoxic concentrations of waxes were evaluated for their activities against skin ageing, including melanogenesis assay, antioxidant activity, collagen content analysis, matrix metalloproteinase-1 and matrix metalloproteinase-2 inhibitory assay and anti-inflammatory activity. RESULTS: Thermal property indicated the endotherm peaks with melting temperatures at 40.89 ± 0.27°C and 69.64 ± 0.34°C for RBS and RBH, respectively. The main fatty acids in RBS were oleic (31.68 ± 0.75%) and linoleic acids (27.19 ± 0.40%), whereas those in RBH were palmitic (36.24 ± 1.08%) and stearic acids (35.21 ± 4.51%). The cytotoxicity assay in single cells and co-culture cells showed the non-cytotoxicity of RBS (0.0001-1 mg/mL) and RBH (0.0001-0.1 mg/mL). The anti-skin ageing activities of 1 mg/mL RBS and 0.1 mg/mL RBH included the melanogenesis inhibition by suppression of tyrosinase and tyrosinase-related protein-2 enzymes, the antioxidant activity by cellular protection against cell damage and cell death, the collagen stimulation, the matrix metalloproteinase-1 and matrix metalloproteinase-2 suppression and the anti-inflammation. CONCLUSIONS: The study results suggest that RBS and RBH can potentially be applied as the functional ingredients in formulations against skin ageing as well as provide the superior benefit on skin moisturization.

OBJECTIF: Les cires de son de riz (Oryza sativa) et les sous­produits de la fabrication de l'huile de son de riz sont largement utilisées comme composants inactifs dans plusieurs préparations. Néanmoins, l'effet des cires de son de riz contre le vieillissement de la peau n'a jamais été rapporté. Cette étude visait à étudier les propriétés thermiques et le profil d'acides gras des cires de son de riz, y compris les cires dures et douces de son de riz, et les activités contre le vieillissement de la peau dans les cellules cutanées en culture. MÉTHODES: La propriété thermique et le profil d'acides gras des cires de son de riz ont été analysés par calorimétrie différentielle à balayage et chromatographie en phase gazeuse couplée spectrométrie de masse, respectivement. Le dosage de la cytotoxicité des cires a été réalisé sur des cellules de mélanome B16F10, des fibroblastes de peau humaine, et des cellules de co­culture de cellules HaCaT et des fibroblastes de peau humaine. Les concentrations non cytotoxiques des cires ont été évaluées pour leurs activités contre le vieillissement de la peau, y compris l'analyse de la mélanogenèse, l'activité antioxydante, l'analyse de la teneur en collagène, le test de l'inhibiteur de la métalloprotéinase matricielle­1 et de la métalloprotéinase matricielle­2 et l'activité anti­inflammatoire. RÉSULTATS: La propriété thermique indiquait des pics endothermes avec des températures de fusion à 40,89 ± 0,27 °C et 69,64 ± 0,34 °C pour les cires dures et douces de son de riz, respectivement. Les principaux acides gras des cires douces de son de riz étaient des acides oléiques (31,68 ± 0,75 %) et des acides linoléiques (27,19 ± 0,40 %), tandis que ceux des cires dures de son de riz étaient des acides palmitiques (36,24 ± 1,08 %) et des acides stéariques (35,21 ± 4,51 %). Le dosage de la cytotoxicité dans les cellules individuelles et les cellules de co­culture a montré la non­cytotoxicité des cires douces de son de riz (0,0001 à 1 mg/ml) et des cires dures de son de riz (0,0001 à 0,1 mg/ml). Les activités antivieillissement de la peau de 1 mg/ml de cire douce de son de riz et de 0,1 mg/ml de cire dure de son de riz comprenaient l'inhibition de la mélanogenèse par suppression des enzymes de la tyrosinase et de la protéine liée à la tyrosinase 2, l'activité antioxydante par protection cellulaire contre les dommages et la mort cellulaires, la stimulation du collagène, la suppression de la métalloprotéinase matricielle­1 et la métalloprotéinase matricielle­2 et l'activité anti­inflammatoire. CONCLUSIONS: Les résultats de l'étude indiquent que les cires dures et douces de son de riz peuvent potentiellement être appliquées comme ingrédients fonctionnels dans des formulations contre le vieillissement de la peau et fournir un bénéfice supérieur en termes d'hydratation de la peau.

Lipid concomitant γ-oryzanol decreased oil absorbency of French fries by changing the microstructure of French fries and physical properties of frying oil.

BACKGROUND: The aim of this research was to evaluate the possibility of lipid concomitant γ-oryzanol reducing oil absorbency of fried foods and the underlying mechanism. Therefore, the influence of γ-oryzanol on moisture and oil content, and distribution and micromorphology of French fries and the viscosity, fatty acid composition and total polar compounds content of rice bran oil (RBO) after frying were studied. RESULTS: Our results showed that the incorporation of low concentration of γ-oryzanol [low addition group (LAG)] (5.754 g/kg) decreased the oil absorbency and porous structure of French fries during frying. Additionally, LAG incorporation inhibited the degradation of linoleic acid, decreased the growth rate of saturated fatty acids, total polar compounds and viscosity of frying oil. CONCLUSIONS: Consequently, it was recommended to incorporate a small amount of γ-oryzanol in frying oil because it could inhibit oil absorption behavior of French fries. © 2023 Society of Chemical Industry.

Development and characterization of hydrogel-in-oleogel (bigel) systems and their application as a butter replacer for bread making.

BACKGROUND: Butter has been widely used in bakery products and it contains high level of saturated fats. However, excessive consumption of saturated fats would increase the risk of chronic disease. This study was to fabricate water-in-oil (W/O) type bigels as butter replacers to improve the quality attributes of breads. RESULTS: A stable water-in-oil (W/O) type bigel system was fabricated based on mixed oleogelators (rice bran wax and glycerol monostearate) and sodium alginate hydrogel. The ratios of oleogel to hydrogel could significantly affect the stability, microstructure and rheological properties of bigels. All of the bigels exhibited solid-like properties, with increased oleogel fractions, and the network structure of bigel became more compact and orderly with smaller sodium alginate gel particles. Meanwhile, the viscoelastic modulus and firmness of bigel increased, contributing to a higher stability. The bigel dough exhibited lower gel strength and relatively higher extensibility compared to the butter dough. Regardless of oleogel fractions, all the bigel produced bread with a higher specific volume and softer texture than the butter bread. When the oleogel fractions was less than 80%, increasing the oleogel fractions was more beneficial for improving the specific volume, softness and fluffy structure of bread. CONCLUSION: W/O type bigel as butter replacers showed great potential in improving the appearance, structure and textural properties of bread. © 2023 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 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.

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.

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.

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.

Genome-wide association study reveals useful QTL and genes controlling the fatty acid composition in rice bran oil using Vietnamese rice landraces.

In rice (Oryza sativa L.), rice bran contains valuable nutritional constituents, such as high unsaturated fat content, tocotrienols, inositol, γ-oryzanol, and phytosterols, all of which are of nutritional and pharmaceuticals interest. There is now a rising market demand for rice bran oil, which makes research into their content and fatty acid profile an area of interest. As it is evident that lipid content has a substantial impact on the eating, cooking, and storage quality of rice, an understanding of the genetic mechanisms that determine oil content in rice is of great importance, equal to that of rice quality. Therefore, in this study, we performed a genome-wide association study on the composition and oil concentration of 161 Vietnamese rice varieties. Five categories of fatty acids in rice bran were discovered and the bran oil concentration profile in different rice accessions was identified. We also identified 229 important markers related to the fatty acid composition of bran oil, distributed mainly on chromosomes 1 and 7. Seven quantitative trait loci and five potential genes related to unsaturated fatty acid content were detected, including OsKASI, OsFAD, OsARF, OsGAPDH, and OsMADS29. These results provide insights into the genetic basis of rice bran oil composition, which is pivotal to the metabolic engineering of rice plants with desirable bran oil content through candidate genes selection.

Evaluation of quantitative synchrotron radiation micro-X-ray fluorescence in rice grain.

Concentrations of nutrients and contaminants in rice grain affect human health, specifically through the localization and chemical form of elements. Methods to spatially quantify the concentration and speciation of elements are needed to protect human health and characterize elemental homeostasis in plants. Here, an evaluation was carried out using quantitative synchrotron radiation microprobe X-ray fluorescence (SR-µXRF) imaging by comparing average rice grain concentrations of As, Cu, K, Mn, P, S and Zn measured with rice grain concentrations from acid digestion and ICP-MS analysis for 50 grain samples. Better agreement was found between the two methods for high-Z elements. Regression fits between the two methods allowed quantitative concentration maps of the measured elements. These maps revealed that most elements were concentrated in the bran, although S and Zn permeated into the endosperm. Arsenic was highest in the ovular vascular trace (OVT), with concentrations approaching 100 mg kg-1 in the OVT of a grain from a rice plant grown in As-contaminated soil. Quantitative SR-µXRF is a useful approach for comparison across multiple studies but requires careful consideration of sample preparation and beamline characteristics.

Rice bran as an encapsulating material to produce a healthy synbiotic product with improved gastrointestinal tolerance.

To date, the coffee industry has the second highest market value in the world and consumer behavior has transitioned from drinking coffee just for its caffeine content to reduce sleepiness into an overall experience. Instant cold brew coffee in powder form can preserve the taste of coffee well; moreover, it is easy to transport. Several consumers have increasing interests in implementing lactic acid bacteria in healthy food due to their growing awareness of the probiotic's role. Several scholars have presented stress adaptation characteristics of single probiotic strains; however, comparisons of the stress-tolerant capacities of different probiotic strains are incomplete. Five lactic acid strains are tested for adaptation under four sublethal conditions. Lactobacillus casei is the most resilient probiotic in terms of heat and cold adaptation, while Lactobacillus acidophilus is more tolerant to low acid and bile salt; Then, these probiotics are subjected to a stress challenge that stimulates drying temperature, including a heat and cold stress challenge. The results show that acid adaptation can improve Lactobacillus acidophilus TISTR 1338 tolerance to harsh drying temperatures. In addition, encapsulation using prebiotic extracts from rice bran, with pectin and resistant starch combined through crosslinking and treated by freeze-drying, provides the highest encapsulation efficiency. In summary, acid-adapted L. acidophilus TISTR 1388 at the sublethal level can be applied to high and low temperature processing techniques. Additionally, the amount of viable probiotic after in vitro digestion remains at 5 log CFU/g, which is suitable for application in the production of synbiotic cold brew coffee.

Anti-inflammatory and antioxidant properties of rice bran oil extract in copper sulfate-induced inflammation in zebrafish (Danio rerio).

Tocotrienols have strong antioxidant properties; however, tocotrienol has not been investigated in detail in aquatic products. In this study, the anti-inflammatory and antioxidant activities of the tocotrienol-rich fraction from rice bran oil and its potential mechanism were verified in a zebrafish CuSO4 inflammation model. The in vitro antioxidant activity was evaluated using the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) stable radical method. The copper chelating activity was determined using the pyrocatechol violet method. Intracellular reactive oxygen species in zebrafish were detected using a fluorescent ROS probe. Transgenic Tg (lyz: DsRed2) zebrafish were used for neutrophil transmigration assays. The mRNA expression levels of antioxidant and pro-inflammatory factor genes were measured using quantitative real-time reverse transcription PCR. In the concentration range tested, 100 µg/mL TRF had the highest copper chelating activity (10%). TRF showed DPPH-free radical scavenging ability, which was 53% at 100 µg/mL TRF. TRF effectively repressed ROS generation and inhibited neutrophil migration to the inflamed site. Moreover, TRF upregulated the expression of antioxidant genes sod and gpx4b, inhibited the expression of pro-inflammatory factors tnfa and il8, and suppressed CuSO4-induced inflammation. In conclusion, TRF has significant anti-inflammatory and antioxidant properties, which supports the use of TRF as an aquatic feed additive to improve the anti-inflammatory and antioxidant capacity of aquatic products.

Complimentary effect of exogenous enzymes, essential amino acids and essential fatty acids supplemented de-oiled rice bran (DORB) based diets on hematology, liver and intestinal histoarchitecture in Labeo rohita.

A 60-day feeding trial was conducted to study the hematology, liver, and intestinal histoarchitecture of Labeo rohita fed with a combination of exogenous enzymes, essential amino acids, and essential fatty acids to DORB (De-oiled rice bran) based diets. Three treatments viz., T1 [DORB + phytase and xylanase (0.01% each)], T2 [DORB + phytase (0.01%) + xylanase (0.01%) + L-lysine(1.4%) + L-methionine (0.4%) + EPA and DHA (0.5%)] and T3 [DORB + phytase (0.01%), xylanase and cellulase (0.075%) + L-lysine (1.4%) +L-methionine (0.4%) + EPA and DHA (0.5%)] were used in the present study. Serum total protein, albumin content and A/G ratio varied significantly (p < 0.05) among groups. Globulin content did not vary significantly among groups (p ≥ 0.05). The Hb content, RBC and MCV count varied significantly (p < 0.05) whereas MCH, MCHC content, WBC and lymphocyte count did not vary significantly among groups (p > 0.05). The liver and intestine examination revealed no visible alteration and showed normal histo-architecture. Based on the finding it is concluded that DORB supplemented with exogenous enzymes, essential amino acids and essential fatty acids with phytase (0.01%), xylanase and cellulase (0.075%), L-lysine (1.4%), DL-methionine (0.4%) and EPA and DHA (0.5%) improves the health of L. rohita.

Effect of Steam Flash-Explosion on Physicochemical Properties and Structure of High-Temperature Denatured Defatted Rice Bran Protein Isolate.

The effects of Steam Flash-Explosion (SFE) on the physicochemical properties and molecular structure of high-temperature denatured defatted rice bran protein isolate (RBPI) were investigated. The mechanism of SFE treatment on high-temperature denatured defatted RBPI was revealed. The analysis of the physical and chemical properties of RBPI showed that the surface hydrophobicity, characteristic viscosity, and thermal stability of rice bran protein isolate were significantly affected by the pressure of saturated steam and pressure holding time. Under the conditions of 2.1 MPa and 210 s, the surface hydrophobicity index decreased significantly from 137.5 to 17.5, and the characteristic viscosity increased significantly. The peak temperature of denaturation decreases from 114.2 to 106.7 °C, and the enthalpy of denaturation decreases from 356.3 to 231.4 J/g. The higher structure (circular dichroic spectrum and endogenous fluorescence spectrum) of rice bran protein isolate was analyzed by volume rejection chromatography (SEC). The results showed that steam flash treatment could depolymerize and aggregate RBPI, and the relative molecular weight distribution changed greatly. The decrease in small molecules with poor solubility was accompanied by the increase in macromolecules (>550 kDa) soluble aggregates, which were the products of a Maillard reaction. The contents of free sulfhydryl and disulfide bonds in high-temperature rice bran meal protein isolate were significantly increased, which resulted in the increase in soluble aggregates containing disulfide bonds. Circular dichroism (CD) analysis showed that the α-helix content of the isolated protein was significantly decreased, the random curl content was increased, and the secondary structure of the isolated protein changed from order to disorder. The results of endogenous fluorescence spectroscopy showed that the high-temperature rice bran meal protein isolate was more extended, tryptophan was in a more hydrophilic microenvironment, the fluorescence intensity was reduced, and the tertiary structure was changed. In addition, the mean particle size and net surface charge of protein isolate increased in the aqueous solution, which was conducive to the development of the functional properties of the protein.