Rice bran oil (RBO) is healthy gift generously given by nature to mankind. RBO is obtained from rice husk, a byproduct of rice milling industry and is gaining lot of importance as cooking oil due to presence of important micronutrient, gamma oryzanol. Its high smoke point is beneficial for its use for frying and deep frying of food stuff. It is popular because of balanced fatty acid profile (most ideal ratio of saturated, monounsaturated and polyunsaturated fatty acids), antioxidant capacity, and cholesterollowering abilities. Rice bran wax which is secondary by-product obtained as tank settling from RBO is used as a substitute for carnauba wax in cosmetics, confectionery, shoe creams etc. It can be also used as a source for fatty acid and fatty alcohol. The article is intended to highlight for the importance of RBO and its applications.
Rice bran is a good source of nutrients that have large amounts of phytochemicals and antioxidants. Conventional rice bran oil production requires many processes that may deteriorate and degrade these valuable substances. Supercritical CO2 extraction is a green alternative method for producing rice bran oil. This work reviews production of rice bran oil by supercritical carbon dioxide (SC-CO2) extraction. In addition, the usefulness and advantages of SC-CO2 extracted rice bran oil for edible oil and health purpose is also described.
This study investigated the physicochemical and antioxidant properties of rice bran oil (RBO) produced from the bran of three rice varities; Khao Dawk Mali 105 (white rice), Red Jasmine rice (red rice) and Hom-nin rice (black rice) using three extraction methods including cold-press extraction (CPE), solvent extraction (SE) and supercritical CO2 extraction (SC-CO2). Yields, color, acid value (AV), free fatty acid (FFA), peroxide value (PV), iodine value (IV), total phenolic compound (TPC), γ-oryzanol, α-tocopherol and fatty acid profile were analyzed. It was found that the yields obtained from SE, SC-CO2 and CPE extractions were 17.35–20.19%, 14.76–18.16% and 3.22–6.22%, respectively. The RBO from the bran of red and black rice samples exhibited high antioxidant activities. They also contained higher amount of γ-oryzanol and α-tocopherol than those of white rice sample. In terms of extraction methods, SC-CO2 provided better qualities of RBO as evidenced by their physicochemical and antioxidant properties. This study found that RBO produced from the bran of black rice samples using SC-CO2 extraction method showed the best physicochemical and antioxidant properties.
Effects of rice bran oil on the oxidative and flavor stability of fish oil were investigated by the gas liquid chromatography-head space method. When fish oil blending with different ratio of rice bran oils was oxidized at room temperature in the dark, volatile compounds produced during autoxidation was measured by gas liquid chromatography. The amounts of volatile compounds were decreased with increased the ratio of blended rice bran oil as well as peroxide value. The level of propanal and acrolein which gave unpleasant flavor was also decreased with increased the ratio of blended rice bran oil. Especially, the level of propanal and acrolein and peroxide value were remarkably decreased when blending more than 75% of rice bran oil. Blending of rice bran oil improved the oxidative and flavor stabilities of fish oil.
This study investigated the carotenoids occurring in the integument of Plectropomus leopardus, the coral trout. For a red specimen, the major carotenoids included astaxanthin diester and monoester, as well as α-cryptoxanthin ester, tunaxanthin diester, adonixanthin diester, adonirubin ester, and adonirubin; for brown and black specimens, tunaxanthin diester was the main carotenoid. 1H-NMR and MS spectral analyses showed that docosahexaenoic acid was the sole fatty acid esterified with xanthophylls in the coral trout.
An indirect enzymatic analysis method for the quantification of fatty acid esters of 2-/3-monochloro-1,2-propanediol (2/3-MCPD) and glycidol was developed, using the deuterated internal standard of each free-form component. A statistical method for calibration and quantification of 2-MCPD-d5, which is difficult to obtain, is substituted by 3-MCPD-d5 used for calculation of 3-MCPD. Using data from a previous collaborative study, the current method for the determination of 2-MCPD content using 2-MCPD-d5 was compared to three alternative new methods using 3-MCPD-d5. The regression analysis showed that the alternative methods were unbiased compared to the current method. The relative standard deviation (RSDR) among the testing laboratories was ≤ 15% and the Horwitz ratio was ≤ 1.0, a satisfactory value.
Arachidonic acid (AA) plays a pivotal role in the development of edema via its oxidized metabolites derived from cyclooxygenase (COX) and lipoxygenase (LOX), and is recently recognized as an activator of TRPV3. However, it is not clear whether AA plays some TRPV3-mediated pathological roles in the development of edema. Pharmacological and histological studies using ICRTRPV3+/+ and ICRTRPV3-/- mice indicated that higher ear edema responses to topical application of AA were observed in ICRTRPV3+/+ mice compared with ICRTRPV3-/- mice. However, there was no difference in the ear edema response to 12-O-tetradecanoylphorbol 13-acetate, skin histology, and skin barrier function between these mouse strains. Furthermore, oxidized fatty acids from the lesional site were analyzed to elucidate the TRPV3-mediated pathological roles of AA, and the results revealed that there were no differences in the level of COX or LOX metabolites derived from AA between both mouse strains. We concluded that AA plays a role in the development of TRPV3-mediated ear edema and that this result may contribute to better understanding of the pathophysiological mechanisms involved in the development of a certain type of edema.
Monoacylglycerol (MAG) and diacylglycerol (DAG) are minor components of edible fats and oils, and they relate to the quality of these foods. The AOCS official method Cd 11b-91 has been used to determine MAG and DAG contents in fats and oils. There are, however, difficulties in the determination of MAG and DAG using this analytical procedure. Therefore, we improved this method by modifying the trimethylsilyl derivatization procedure and replacing the internal standard (IS) material. In our modified method, TMS-HT (mixture of hexamethyldisilazane and trimethylchlorosilane) was used for derivatization of MAG and DAG, which was followed by liquid-liquid extraction with water and n-hexane solution containing the IS, tricaprin. Using the modified method, we demonstrated superior repeatability in comparison with that of the AOCS method by reducing procedural difficulties. The relative standard deviation of distearin peak areas was 1.8% or 2.9% in the modified method, while it was 5.6% in the AOCS method. In addition, capillary columns, such as DB-1ht and DB-5ht could be used in this method.
Phospholipid peroxidation is considered to be involved in the pathophysiology of various diseases. While dietary antioxidants are believed to help prevent these diseases via inhibition of phospholipid peroxidation, further evaluation is needed to prove this hypothesis. For this, it is crucial to establish an animal model with accelerated phospholipid peroxidation. In this study, we hypothesized that a combination of aging and high-fat diet feeding may accelerate phospholipid peroxidation in vivo. High-fat diets were fed to mature and juvenile Fischer 344 rats for 12 weeks. The mature rats in particular accumulated body fat and liver phosphatidylcholine hydroperoxide (PCOOH). Interestingly, the increase in PCOOH levels was abrogated by the co-administration of antioxidants to mature rats. This may be attributed to factors including the decrease in body fat, functions of vitamin E, and/or the involvement of antioxidant-related genes, each caused by antioxidant administration. These results indicate that the high-fat diet-fed aging animal model may be suitable for investigation of the relationship between phospholipid peroxidation, oxidative stress-related diseases, and dietary antioxidants.
Zhenjiang fragrant vinegar (Kozu) is a black rice vinegar that has been used as a traditional Chinese medicine and has various health benefits, including anti-obesity effects. In the present study, using luciferase reporter assays of PPARγ promoter activity, a novel ingredient from 8-year-old Kozu, 5-hydroxy-4-phenyl-butenolide, was isolated. The newly found agonist was named as “Fraglide-1”. Moreover, in subsequent experiments, it was confirmed that fraglide-1 was an PPARγ agonist and it could increase expression level of the uncoupling protein (UCP)-1. Fraglide-1 was chemically synthesized and it was verified that expression of the PPARγ was increased in dose dependent manner. Although Kozu has been consumed globally as a functional food for thousands of years, the mechanisms behind its health effects have not been characterized. The active ingredient of Kozu was successfully found and the results unraveled a longtime mystery about Kozu for its beneficial health effect.
We specially carried out the subcritical butane extraction to separate abamectin from tea leaves. Four parameters, such as extraction temperature, extraction time, number of extraction cycles, and solid-liquid ratio were studied and optimized through the response surface methodology with design matrix developed by Box–Behnken. Seventeen experiments with three various factors and three variable levels were employed to investigate the effect of these parameters on the extraction of abamectin. Besides, catechins, theanine, caffeine, and aroma components were determined by both high-performance liquid chromatography and gas chromatography–mass spectrometry to evaluate the tea quality before and after the extraction. The results showed that the extraction temperature was the uppermost parameter compared with others. The optimal extraction conditions selected as follows: extraction temperature, 42°C; number of extraction cycles and extraction time, 1 and 30 min, respectively; and solid–liquid ratio, 1:10. Based on the above study, the separation efficiency of abamectin was up to 93.95%. It is notable that there has a quite low loss rate, including the negligible damage of aroma components, the bits reduce of catechins within the range of 0.7%–13.1%, and a handful lessen of caffeine and theanine of 1.81% and 2.6%, respectively. The proposed method suggested subcritical butane possesses solubility for lipid–soluble pesticides, and since most of the pesticides are attached to the surfaces of tea, thus the as-applied method was successfully effective to separate abamectin because of the so practical and promising method.
This study was designed to examine physicochemical characteristics, chemical compositions and biological activities of fenugreek seed oil (FSO) and its pure triglyceride (TG). One fenugreek TG was purified using a bioassay-guided fractionation and administrated to surviving diabetic rats. The free fatty acids percentage as well as, the peroxide, the saponification and the iodine values were 2%, 12 mequiv. O2/kg of oil, 189 (mg KOH/g) and 110 (g/100 g of oil), respectively. Linolenic acid (C18:3 26.14%), Linoleic acid (C18:2 41.13%) and Oleic acid (C18:1 17.07%) were the dominant fatty acids in the FSO. β-sitosterol was the major sterol (85.3%) in the FSO. LnLnO (17.1%), LLL (16.6%), OLL and OOLn (8.4%), were the abundant triglycerides. The hexane extract of fenugreek seed (exhibiting the powerful inhibitory activity against alpha-amylase) was purified using a bioassay-guided fractionation affording one fenugreek TG: (11Z)-11- eicosenoic acid 2, 3- bis[((9Z, 12Z, 15Z)-1-oxo-9, 12, 15-octadecatrien-1-yl)oxy] propyl ester. In diabetic rats, the administration of the fenugreek TG inhibited α-amylase activity in small intestine by 36% as compared to untreated diabetic rats. Moreover, fenugreek TG increased insulin sensibility which leads to decrease in blood glucose level by 43%. In addition, this study demonstrated that administration of pure fenugreek TG to diabetic rats ameliorated the glycogen rate in liver and muscle. In addition, the administration of fenugreek TG reverted back the activity of angiotensin converting enzyme respectively in kidney and plasma by 33 and 29%. Interestingly, the fenugreek TG inhibited lipase activity in small intestine by 33% which leads to the regulation of lipid profile. Moreover, the fenugreek TG protected liver-kidney function evidenced by histological study. In conclusion, our finding demonstrates that the administration of fenugreek TG to diabetic rats can make it a potential candidate for industrial application as a pharmacological agent for the treatment of hyperglycemia.
In the present research, we prepared an acidic liposome as a cell model and used confocal laser microscopy to evaluate its interaction with oligopeptides that had high membrane permeability or affinity. The results showed that, for short peptides of about ten residues, the positive charge peptides interacted with the acidic liposome strongly. For peptides that interacted with the liposome, no difference was found between linear-chain and branched-chain peptides due to their structure.
Some acetic acid bacteria produce large amounts of glyceric acid (GA) from glycerol in culture broth. However, methanol, which is a major contaminant of raw glycerol derived from the biodiesel fuel industry, sharply decreases cell growth and GA production [AMB Express, 3, 20, 2013]. Thus, we evaluated the methylotrophic acetic acid bacterium Acidomonas methanolica NBRC104435 for its ability to produce GA from glycerol containing methanol. This strain accumulated GA in its culture broth when 1–3 wt% glycerol was available as a carbon source. We observed improved cell growth and GA accumulation when 1 vol% methanol was added to the 3–5 wt% glycerol medium. The maximum concentration of GA was 12.8 g/L in medium containing 3 wt% glycerol plus 1 vol% methanol. In addition, the enantiomeric excess (ee) of the GA produced was revealed to be 44%, indicating that this strain converted glycerol to d-GA with a lower enantioselectivity than other acetic acid bacteria, which had 70–99% ee.