Bran Lipids Research Articles

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.

Facile analysis of rice bran oil to compare free unsaturated fatty acid compositions of parental and hybrid rice lines.

Rice bran oil (RBO) has been a popular choice of cooking oil in several Asian countries for decades, and the interest in RBO is fast growing in Western countries due to the high levels of hearty unsaturated fats and other components beneficial to health. Further knowledge of unsaturated fatty acid content and composition in rice lines will assist in improving the quality of rice bran processing by allowing robust extraction of rice bran for oil production. The studies focused on the RBO composition of rice lines with beneficial genotypes are scarce. Accordingly, we investigated the total bran lipid content and composition of three of the most abundant, healthy, unsaturated fatty acids that freely exist in RBO: oleic, linoleic, and α-linolenic acids in nine parental lines (two male sterile lines and seven male lines) and seven hybrid rice lines, by utilizing an efficacious organic extraction to collect RBO and by developing a user-friendly reverse-phase high-performance liquid chromatography (HPLC) methodology. Our results showed that the hybrid lines had the highest oil content (F ratio = 7.2017, p value = 0.0019), while the male lines had the highest levels of two of the three free unsaturated fatty acids analyzed (linoleic acid, mg and oleic acid, mg). Oil weight was negatively correlated with α-linolenic acid (r = -0.6535, p value <0.0001). All three free unsaturated fatty acids were positively correlated. Our samples' natural variation in lipid content suggests that some rice lines are more suitable for oil production.

An Environmentally Friendly Approach for the Release of Essential Fatty Acids from Cereal By-Products Using Cellulose-Degrading Enzymes.

Simple SummaryFatty acids, especially the representatives of essential mono- and polyunsaturated ones, play an important role in the human organism, as they are involved in the regulation of the immune and central nervous systems. Whole grain products are considered to be a rich source of multiple health-promoting phytochemicals, including fatty acids, where polyunsaturated fatty acids take prevalence over saturated ones. To improve the milling performance of grain and ensure the high-quality standards of flour, technologies presently utilized within the milling process, e.g., dehulling and debranning, generally aim at removing outer layers of cereal grain and result in substantial reduction of valuable nutrients along with loss of functionality. In spite of the relative abundance of valuable compounds in cereal bran, currently less than 10% of produced bran is used in the food industry. To valorize cereal bran for food and pharmaceutical applications, additional pre-treatment is required.The main intention of the present work was to investigate the ability of cellulose-degrading enzymes (C-DE) to release fatty acids (FAs) from complex matrices of cereal by-products during enzymatic hydrolysis (EH). For this purpose, three types of cereal bran (CB), i.e., wheat, rye, and oat, were used as lignocellulose substrates for three commercially available hydrolytic enzymes, i.e., Viscozyme L, Viscoferm, and Celluclast 1.5 L. The yield and composition of FAs after EH were assessed and compared with those obtained after either conventional Soxhlet extraction or after alkaline-assisted hydrolysis (A-AH) with 10% KOH in 80% MeOH and subsequent liquid–liquid extraction. The experimental results demonstrated that up to 6.3% and 43.7% higher total FA yield can be achieved by EH of rye bran using Celluclast 1.5 L than by A-AH and Soxhlet extraction, respectively. However, the application of Viscoferm for EH of wheat bran ensured up to 7.7% and 13.4% higher total FA yield than A-AH and Soxhlet extraction, respectively. The concentration of essential linolenic acid (C18:3) in lipids extracted after EH of rye bran with Celluclast 1.5 L was up to 24.4% and 57.0% higher than in lipids recovered by A-AH and Soxhlet extraction, respectively. In turn, the highest content of linolenic acid in wheat bran lipids was observed after EH with Viscoferm and Viscozyme L, ensuring 17.0% and 13.6% higher yield than after A-AH, respectively. SEM analysis confirmed substantial degradation of the CB matrix promoted by the ability of C-DE to act specifically on glycosidic bonds in cellulose and on xylosidic bonds in arabinoxylans, arabinans, and other arabinose-containing hemicelluloses. Structural alterations in cell integrity greatly contributed to the release of bound FAs and their better transfer into the extraction solvent. It has been shown that the proposed process of EH can be used for the efficient release of FAs from the CB matrix more sustainably and with a safer profile, thereby conveying greener production of FAs for certain purposes.

A Holistic View of the Genetic Factors Involved in Triggering Hydrolytic and Oxidative Rancidity of Rice Bran Lipids

ABSTRACT The bran fraction of rice grains is used for extracting nutritious edible oil known as rice bran oil (RBO). In spite of its nutritional quality, bran lipids have a lower shelf-life due to the hydrolytic and oxidative rancidity. During the rice grain milling, endogenous lipases come in contact with storage lipids or triacylglycerols (TAGs) in the ruptured bran layers. The fatty acid ester bonds in the TAGs are hydrolyzed by the lipases causing the release of free fatty acids (FFAs) and glycerol. Further oxidation of these FFAs, especially the linoleic acid (18:2), are further oxidized by the action of lipoxygenases (LOXs). This reaction produces conjugated hydroperoxides of 18:2, which decompose and form secondary oxidation products responsible for the strong undesirable stale off-flavors. The outcome is a deterioration of bran lipids and significant loss of TAGs during RBO refining process. Therefore, this review aims to provide a holistic view on the current understanding of the catalog of genes and the underlying molecular mechanisms involved in triggering bran lipid rancidity. Generated knowledge about the individual genes will be crucial for developing advanced genome editing strategies to regulate rice bran lipid quality and stability.

Biodiesel from rice bran lipids: resource assessment and technological review

The biodiesel (BD) industry struggles to compete with petroleum diesel because of its high cost, primarily attributed to the costs of raw material and production. Rice bran (RB) is an oleaginous agro-industrial residue which has been of interest as a feedstock for BD production. Although RB has been found to be a potential resource for various products of commercial interest, its current bulk but limited utilization is either as a source of edible oil or as an ingredient of feeds. A key challenge in processing lipids from rice bran is its significant free fatty acid content but is not necessarily a setback when utilized for biodiesel production. Despite the perceived potential, the sheer number of published researches, and even patented processes, there has been no quantitative assessment of the resource availability, and no commercialized process reported. In this work, a localized resource assessment with biodiesel yield estimates has been conducted to identify priority areas for adapting rice bran for biodiesel production. As leading paddy rice producers, Southern, Eastern, and Southeastern Asian regions were found to have potential in adapting RB as a biodiesel feedstock. Alongside this, detailed technological comparisons were described in this review, from lipid extraction, reaction systems or schemes, reactants, catalysts, reactor configurations and strategies, to emerging and patented technologies with economical and scalable potential. In addition, opportunities in (RB) processing and related government policies, foreseen impacts on economics, social, and environmental aspects, as well as existing challenges, were identified and discussed for future prospects and developments.

A Systemic Design Approach Applied to Rice and Wine Value Chains. The Case of the InnovaEcoFood Project in Piedmont (Italy)

Attention to food waste is an increasingly growing phenomenon today, especially in the context of a circular economy. The InnovaEcoFood project investigates the use of by-products of the Piedmontese rice and wine production chains to valorize their untapped potential in the food sector by applying the Systemic Design approach. We collected, systematized, and visualized a range of solutions for exploiting these by-products, starting from an in-depth literature review on the two value chains. With the support of a consortium of partners from both multidisciplinary industrial and academic sectors, it was possible to validate the links that have been generated. Eventually, the project created food products that integrated these outputs as ingredients (like flour and butter) because they have antioxidant properties and are rich in proteins. InnovaEcoFood has successfully tested how value could be created from waste. Moreover, using rice hull, marc flour, and bran lipid (butter) is of immediate technical and economic feasibility. It could be considered a viable way that deserves further experimentation.

Mobilization of storage lipid reserve and expression analysis of lipase and lipoxygenase genes in rice (Oryza sativa var. Pusa Basmati 1) bran during germination

Storage lipid mobilization by lipases and lipoxygenases (LOXs) in response to developmental cues take place during seed germination. After rice grain milling, the endogenous lipases and LOXs present in the bran fraction come in contact with the storage lipid reserve or triacylglycerol (TAG). Lipases catalyze the hydrolysis of TAGs to non-esterified fatty acids (NEFAs) and glycerol. The NEFAs, especially linoleic acid (18:2) produced, are further subjected to oxidative rancidity via peroxidation reaction catalyzed by LOXs. This results in the production of conjugated hydroperoxides of 18:2 that influence the off-flavors in rice bran lipids. The aim of this study is to understand how lipid mobilization and expression of lipase and LOX genes occur in the bran of germinating rice grains (Oryza sativavar. Pusa Basmati 1). Our results show that the primary source of storage lipids in bran is TAG, and its mobilization starts at 4 days after imbibition (4 DAI). Using publically available RNA-seq data and phylogeny analyses, we selected a total of 18 lipase and 16 LOX genes in rice for their expression profiles during onset of lipid mobilization. Gene expression analyses revealed OsLip1, OsLip9, and OsLip13; and OsLOX3 and OsLOX14 as the predominantly expressed genes in bran of germinating rice grains. This study explores two important events in the germinating rice grains, namely, mobilization of storage lipids and expression pattern of lipase and LOX genes. The information generated in this study can be used to efficiently manipulate the genes to enhance the shelf-stability of bran lipid reserve.

Improved solvent economy and rate of rice bran lipid extraction using hydrolyzed rice bran with hexane as solvent

This study provides kinetic and equilibrium information of the extraction of rice bran lipids using hexane from post-hydrolysis rice bran (PHRB). Rice bran (RB) is an agricultural residue with promising valorization potential in biodiesel production. In this study, native RB was subjected to dilute acid hydrolysis (DAH) with an acid solution 3 vol% using 95 wt% H2SO4 at 90 °C for 6 h, increasing the lipid density threefold. Batch extraction with hexane was carried out at various temperatures (30, 45, and 60 °C) and solvent to solid ratio (SSR, 4, 8, and 12 mL g−1). Improved extraction rates were observed at higher temperatures and lower SSRs. Regardless, ~90% of the extractable lipids were solubilized in hexane in less than 10 min. Data obtained were fitted with 5 different models. The extraction of lipids from RB and PHRB involves at least 2 mechanisms, a rapid washing step, and a diffusion step. The extraction process was found to be exergonic, endothermic, and irreversible. An SSR of 4 mL g−1 would require at least 5 ideal crossflow extraction stages for a lipid recovery of over 95%. Compared to RB, the extraction of lipids from PHRB provides potential solvent savings of ~80%.

Storage characteristics of infrared radiation stabilized rice bran and its shelf-life evaluation by prediction modeling.

Rice bran is a nutrient-dense and resource-rich byproduct produced from the rice milling. The limitation of rice bran utilization is mainly caused by oxidative deterioration. Improvement of stability to prolong rice bran shelf-life has thus become an urgent requirement. The present study aimed to determine the characteristics of infrared radiation heat treatment of rice bran (IRRB) and raw rice bran stored under different temperatures. The effects of heating and storage time on physicochemical, microbial, storage stability and structural properties were investigated. Additionally, the prediction model for the shelf-life of rice bran was established based on free fatty acids and the peroxide value by fitting the curve of bran lipid oxidation. The results obtained demonstrated that infrared radiation heating at 300 °C for 210 s resulted in decreased lipase activity and peroxidase activity of 73.05% and 81.50%, respectively. The free fatty acids and peroxide value of IRRB stored at 4 and 25 °C for 8 weeks were only reached at 2.35% and 3.17% and 2.53 and 3.64 meq kg-1 , respectively. The shelf-life prediction model showed the the shelf-life of infrared radiation-treated samples increased to 71.6 and 25.8 weeks under storage at 4 and 25 °C, respectively. The stabilizing process could effectively suppress microbial growth and had no prominent effect on the physicochemical and microstructure properties of rice bran and, simultaneously, storage life was greatly extended. © 2020 Society of Chemical Industry.

Concentrated Phosphatidic Acid in Cereal Brans as Potential Protective Agents against Indomethacin-Induced Stomach Ulcer.

One of complications associated with long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) is peptic ulcer. Recently, we found that orally administered phosphatidic acid (PA) ameliorated aspirin-induced stomach lesions in mice. In this study, we identified PA-rich food sources and examined the effects of the food materials on indomethacin-induced stomach ulcer. Among examined, buckwheat (Fagopyrum esculentum) bran contained the highest level of PA (188 mg/100 g). PA was the richest phospholipid (25%) in the lipid fraction of the buckwheat bran. Administration of the lipid extracts of buckwheat bran significantly ameliorated indomethacin-induced stomach lesions in mice. In contrast, wheat (Triticum durum) bran lipids (PA, 4%) and soybean (Glycine max) lipids (PA, 3%) were not associated with ameliorative effects. These results indicated that PA-rich lipids can be used as an effective supplement for prevention of NSAID-induced stomach ulcer.

Protease Treatment for the Stabilization of Rice Bran: Effects on Lipase Activity, Antioxidants, and Lipid Stability

ABSTRACTRice bran lipid is rapidly made rancid by endogenous lipase enzymes. To inactivate rice bran lipase, an enzymatic hydrolytic method was developed and then compared with the thermal method. The efficiency of five proteolytic enzymes including trypsin, chymotrypsin, papain, bromelain, and Flavourzyme enzyme to stabilize rice bran was investigated. Moreover, the antioxidant content and storage stability of enzymatically stabilized rice bran (ESRB), thermally stabilized rice bran (TSRB), and raw rice bran (RRB) were studied. Trypsin, chymotrypsin, and papain showed a higher rate of hydrolysis than bromelain and Flavourzyme enzyme. After 120 min of hydrolysis, rice bran hydrolyzed by trypsin, chymotrypsin, and papain inactivated 80, 86, and 79% of lipase activity, respectively, whereas lipase activity of rice bran hydrolyzed by bromelain and Flavourzyme enzyme was higher than the initial rice bran. With a similar lipase inactivation level, the cheaper papain was used to produce ESRB. Total phenolics content of ESRB was 52.89 and 94.10% higher than in RRB and TSRB, respectively. In addition, γ‐oryzanol content in ESRB was 2.23‐ and 2.05‐fold of that in RRB and TSRB, respectively. Lipase activity of RRB increased throughout the two months of storage, whereas no change in lipase activity was observed in ESRB and TSRB. At the end of storage, free fatty acid contents of RRB, TSRB, and ESRB were 15.30, 4.67, and 3.92%, respectively. We propose enzymatic hydrolysis by papain for stabilization of rice bran with high antioxidant content and storage stability.

Vitamin E Profiles and Triacylglycerol Molecular Species of Colored Rice Bran Cultivars at Different Degree of Milling

The objective of this study was to evalute the tocochromanol distributions, lipid components and molecular species of triacylglycerols (TAG) in three colored rice bran cultivars. The dominant tocochromanol were gama-tocotrienol, alpha-tocopherol and alpha-tocotrienol with smaller amounts of gama-tocopherol, delta-tocopherol and delta-tocotrienol. These lipids comprised mainly TAG (78.0-81.6 wt%), free fatty acids (FFA: 5.6-8.8 wt%), and phospholipids (PL: 6.3-7.0 wt%), while other components were present in minor proportions (0.4-2.3 wt%). Sixteen different TAG molecular species were detected and quantified by successive applications of AgNO&lt;sub&gt;3&lt;/sub&gt;-TLC and GC. The major TAG molecular species were SM&lt;sub&gt;2 &lt;/sub&gt;(6.1-9.8%), S&lt;sub&gt;2&lt;/sub&gt;D (4.8-7.3%)?M&lt;sub&gt;3&lt;/sub&gt; (16.4-18.7%), SMD (6.2-9.2%), SD&lt;sub&gt;2&lt;/sub&gt; (6.5-9.5%), SMT (6.3-7.7%), M&lt;sub&gt;2&lt;/sub&gt;D (12.3-15.5%.), MD&lt;sub&gt;2&lt;/sub&gt; (8.4-10.4%), SDT (4.3-5.4%) and D&lt;sub&gt;3&lt;/sub&gt; (10.2-15.2%) (where S, M, D, and T denote saturated FA, monoene, diene, and triene, respectively). The results showed that colored rice bran lipids contain large amounts of nutraceutical with proven positive health effects.

Variation in Fatty Acid Distribution of Different Acyl Lipids in Rice (Oryza sativa L.) Brans

The lipids extracted from rice brans were classified by thin-layer chromatography into eight fractions, and their fatty acid (FA) compositions were investigated among five different Japanese cultivars. The lipids of these rice brans comprised mainly triacylglycerols (TAG; 84.9-86.0 wt%), free FA (4.2-4.6 wt%), and phospholipids (PL; 6.5-6.7 wt%), whilst other components were also detected in minor proportions (0.2-2.1 wt%). The PL components included phosphatidyl choline (43.3-46.8 wt%) phosphatidyl ethanolamine (25.0-27.3 wt%) and phosphatidyl inositol (20.2-23.2 wt%). Comparison of the different cultivars showed, with a few exceptions, no substantial difference (P > 0.05) in FA distribution. FA distribution of TAG among the five cultivars was characterized as: unsaturated FA predominantly concentrated at the sn-2 position and saturated FA primarily occupying the sn-1 or sn-3 position in these lipids. These results suggest that the rice bran lipids may be well incorporated into our daily diet to improve nutritional value of the Japanese diet.

Activity of gaseous phase steam distilled propolis extracts on peroxidation and hydrolysis of rice lipids

The effects of simultaneous steam distilled extracts of Brazilian propolis in the static gas phase on curbing peroxidation and hydrolysis in rice lipids were examined. Gas chromatograph–mass spectrometry analysis and subsequent fragment pattern identification revealed the presence of over 30 compounds. Propene, acetophenone and beta-linalool were some of the dominant fractions. The peroxide value (POV) of extracted rice bran lipids was lower in samples treated with propolis extract than in rosemary oil-soluble (RM21Bbase) and water-soluble (RM21Abase) extracts that were used as positive controls. Except for rosemary oil-soluble extract (RM21Bbase), the rest of the treatments (propolis and rosemary water-soluble (RM21Abase) extracts) suppressed the accumulation of α-linolenic and linoleic acids. Assessment of the lipolytic associated freshness indices: plate count agar for total aerobic bacterial count, potato dextrose agar for total yeast, and mold counts as well as carbon dioxide evolution of the stored brown rice revealed a strong antimicrobial activity associated with the depression of carbon dioxide evolution after treatment with propolis extracts. This is the first report on Brazilian propolis extract in the static gas phase displaying an antilipolytic efficacy on rice lipids.

Extraction of rice brain oil using supercritical carbon dioxide and propane

AbstractExtraction of rice bran lipids was performed using supercritical carbon dioxide (SC−CO2) and liquid propane. To provide a basis for extraction efficiency, accelerated solvent extraction with hexane was performed at 100°C and 10.34 MPa. Extraction pressure was varied for propane and SC−CO2 extractions. Also, the role of temperature in SC−CO2 extraction efficiency was investigated at 45,65, and 85°C. For the SC−CO2 experiments, extraction efficiencies were proportional to pressure and inversely proportional to temperature, and the maximal yield of oil achieved using SC−CO2 was 0.222±0.013 kg of oil extracted per kg of rice bran for conditions of 45°C and 35 MPa. The maximal yield achieved with propane was 0.224±0.016 kg of oil per kg of rice bran at 0.76 MPa and ambient temperature. The maximum extraction efficiencies of both SC−CO2 and propane were found to be significantly different from the hexane extraction baseline yield, which was 0.261±0.005 kg oil extracted per kg of rice bran. A simulated economic analysis was performed on the possibility of using SC−CO2 and propane extraction technologies to remove oil from rice bran generated in Mississippi. Although the economic analysis was based on the maximal extraction efficiency for each technology, neither process resulted in a positive rate of return on investment.

Phytosterols in cereal by‐products

AbstractPhytosterols are hypocholesterolemic. Like corn fiber oil, the lipid extracts of certain cereal by‐products may be rich sources of these health‐promoting compounds. The objective of this research was to examine the phytosterol content and composition of various cereal by‐products. Total lipids in rice bran, wheat bran, wheat germ, durum wheat (bran and germ mixture), oat bran, oat hull, and corn fine fiber were extracted, and the sterol profiles of the extracted lipids were analyzed by GC. Rice bran contained the most lipids (22.2%), followed by wheat germ, durum wheat, oat bran, wheat bran, and oat hull; corn fine fiber contained the least amount of lipids (1.7%). Sitosterol, campesterol, and stigmasterol were the major phytosterols in these lipid extracts, whereas brassicasterol was detected only in wheat samples. Rice bran oil contained considerable amounts of cycloartenol and 24‐methylenecycloartanol, which were unique to these samples. Total sterol concentrations in extracted lipids were similar for rice bran, wheat bran, wheat germ, and durum wheat (21.3–15.1 mg/g), but they were very low in oat bran lipids and oat hull lipids (3.4 and 8.2 mg/g, respectively). Corn fine fiber lipids contained the highest amount of sterols (48.3 mg/g). Rice bran appears to be the best source of phytosterols, with the highest oil content and high concentration of sterols.

Rational improvement of centrifugal partition chromatographic settings for the production of 5- n-alkylresorcinols from wheat bran lipid extract : I. Flooding conditions—optimizing the injection step

A dedicated CPC prototype permits direct flow pattern visualization in the partition cells of a CPC column. It was used to understand “flooding”, a frequent phenomenon associated with large injections. A general strategy was developed to optimize the injection step in the framework of a particular preparative separation: the purification of 5- n-alkylresorcinols from a wheat bran lipid extract on a several hundred milligram scale. The construction of the “mobile phase/stationary phase/sample” pseudo ternary diagram characterizes the effect of the injected solution on mobile and stationary phases. The position of the binodal curve maximum indicates if the biphasic system is “robust” towards a large injection or not, and can be used for optimum mass load determination.

Supercritical CO2 extraction of rice bran

AbstractExtraction of rice bran lipids with supercritical carbon dioxide (SC‐CO2) was performed. To investigate the pressure effect on extraction yield, two isobaric conditions, 7000 and 9000 psi, were selected. A Soxhlet extraction with hexane (modified AOCS method Aa 4–38; 4 h at 69°C) was also conducted and used as the comparison basis. Rice bran with a moisture content of 6%, 90% passable through a sieve with 0.297 mm opening, was used for extraction. A maximum rice bran oil (RBO) yield of 20.5%, which represents 99+% lipid recovery, was obtained with hexane. RBO yield with SC‐CO2 ranged between 19.2 and 20.4%. RBO yield increased with temperature at isobaric conditions. At the 80°C isotherm, an increase in RBO yield was obtained with an increase in pressure. The pressure effect may be attributed to the increase in SC‐CO2 density, which is closely related to the value of the Hildebrand solubility parameter. RBO extracted with SC‐CO2 had a far superior color quality when compared with hexane‐extracted RBO. The level of sterols in SC‐CO2‐extracted RBO increased with pressure and temperature.

Oxidative Stability of Bran Lipids from Rice Variety [Oryza sativa (L.)] Lacking Lipoxygenase-3 in Seeds

Lipoxygenase-3 (LOX-3) is the major component among isozymes in rice seeds. Using the Thai rice variety Daw Dam, which lacks LOX-3 in its seed, and the Japanese rice varieties Koshihikari and Koganemochi, which have normal LOX-3 activity, the oxidative stability of lipids in rice bran fractions during storage at 4 and 37 °C was studied. Free fatty acid content in lipids differed between storage temperatures and peroxide value (POV) differed among varieties. Differences among varieties and between storage temperatures in carbonyl value (COV) in lipids were observed. The amounts of free linoleic and linolenic acids did not differ among varieties during storage at either temperature. POV and COV in Daw Dam were lower, however, than in the other two varieties. These results suggest that the peroxidation of unsaturated fatty acids occurs at lower levels in the Daw Dam bran fraction than in the varieties with LOX-3 in their seed. The effect of this lack of LOX-3 as it relates to rice grain stability is discussed. Keywords: Bran lipid; carbonyl compound; free fatty acid; lipoxygenase-3; peroxide; rice

Effects of rice bran lipids and fermentation temperatures on the characteristics of aromatic red rice wine

The lipid fraction extracted from the bran layer of aromatic red rice ( Oryza sativa var. Indica, Tapol) did not show a direct influence on the characteristic aroma formation in aromatic red rice wine. The optimal temperature for aromatic red rice wine brewing was rather higher (25°C) than that of traditional sake brewing (7–16°C).