Rice bran oil

About: Rice bran oil is a research topic. Over the lifetime, 2102 publications have been published within this topic receiving 32504 citations.

Enzymatic transesterification of fractionated rice bran oil with conjugated linoleic acid: Optimization by response surface methodology

Abstract: Rice bran oil (RBO) was fractionated at a low temperature (−16 °C) and the yield of fractionated solid (S-RBO) and liquid (L-RBO) phase were 66.5 and 33.5 g/100 g, respectively. The L-RBO contained more unsaturated fatty acids (81.8%) than S-RBO (76.1%). Response surface methodology (RSM) was used to determine the effects of three variables (water activity of lipase, reaction temperature and time) on the lipase catalyzed incorporation of conjugated linoleic acid (CLA) into L-RBO. We used CLA as the acyl due to its purported health benefits. The transesterified lipid (TL) contained palmitic (13.5%), oleic (37.5%), linoleic (26.6%) and CLA isomers (20.7%), respectively. According to ridge analysis, optimal reaction conditions for water activity of lipase, reaction temperature and time were 0.177, 55.66 °C and 29.25 h, respectively, for producing TL with maximum incorporation of CLA. The coefficient of determination (R2=0.94) showed that the fitted model explained 94% of the observation. The TL was reproduced to confirm the experimental incorporation with the estimated value. The data showed that the experimental response was reasonably close to the estimated response. These results suggested that RSM can be used to optimize lipase-catalyzed incorporation of CLA into the fractionated L-RBO.

The in vitro hydrolysis of phytosterol conjugates in food matrices by mammalian digestive enzymes.

Abstract: All fruits, vegetables, and grains contain phytosterols Numerous clinical studies have documented that phytosterols lower LDL-cholesterol levels and thereby reduce the risk of cardiovascular disease Most experts believe that the cholesterol-lowering mechanism of phytosterols requires that they be in their "free" form In addition to their occurrence in the free form, phytosterols also occur as four common phytosterol conjugates: (i) fatty acyl esters, (ii) hydroxycinnamate esters, (iii) steryl glycosides, and (iv) fatty acylated steryl glycosides This study was undertaken to investigate the extent of hydrolysis of four common phytosterol conjugates by mammalian digestive enzymes (cholesterol esterase and pancreatin, a mixture of pancreatic enzymes) and for comparison purposes, by KOH Two types of purified hydroxycinnamate esters (sitostanyl ferulate and oryzanol, a mixture of hydroxycinnamate esters purified from rice bran oil) were hydrolyzed by cholesterol esterase and by pancreatin Both cholesterol esterase and pancreatin hydrolyzed the phytosteryl esters in two functional food matrices, and they hydrolyzed the hydroxycinnamate esters in corn fiber oil This is the first report to demonstrate that phytostanyl ferulate esters (which are present at levels of 3-6% in corn fiber oil) are hydrolyzed by pancreatic cholesterol esterase It is also the first report that pancreatin contains enzymes that hydrolyze the fatty acyl moiety of fatty acylated steryl glycoside, converting it to steryl glycoside Pancreatin had no effect on steryl glycosides The ability of pancreatin to hydrolyze three other types of lipid conjugates was also evaluated Phospholipids were completely hydrolyzed About half of the galactolipids were hydrolyzed, and less than 10% of the polyamine conjugates were hydrolyzed The extents of hydrolysis of phytosteryl esters by base (saponification) were also studied, and conditions commonly used for the saponification of acyl lipids (15 N methanolic KOH, 30 min at 70 degrees C), were found to result in a nearly 100% hydrolysis of TAG but only about 35-45% hydrolysis of the phytosteryl fatty acyl esters or phytosteryl hydroxycinnamate esters

Zero-trans shortening using palm stearin and rice bran oil

Abstract: Several pilot-scale trials reported in this paper, using palm stearin-rice bran oil (PS-RBO) blends, obviously did not contain trans FA (TFA), whereas the commercial products were found to contain 18–27% TFA. The effects of processing conditions such as rate of agitation, crystallization temperature, and composition of the blends on the crystal structure of shortenings were studied. The products were evaluated for their physicochemical characteristics using DSC, X-ray diffraction (XRD), HPLC, and FTIR techniques. The formulation containing 50% PS and 50% RBO showed melting and cooling characteristics similar to those of hydrogenated commercial “vanaspati” samples. Analysis of the FA composition revealed that the formulated shortenings contained 15–19% C18∶2 PUFA. Tocopherol and tocotrienol contents of the experimental shortenings were in the range of 850–1000 ppm with oryzanol content up to 0.6%. XRD studies demonstrated that the crystal form in the shortenings was predominantly the most stable β′ form, and there was less of the undesirable β form.

Biodiesel from Rice Bran Oil: Transesterification by Tin Compounds

Abstract: The transesterification of rice bran oil with methanol has been studied in the presence of sulfuric acid (H2SO4), tin chloride dihydrate (SnCl2·2H2O), tin 2-ethylhexanoate (Sn(C8H15O2)2), dibutyl tin oxide ((C4H9)2SnO), and dibutyl tin dilaurate ((C4H9)2Sn(C12H23O2)2), known commercially as DBTDL. Through the comparative analysis among the catalysts, we observed that the complex DBTDL presented the best performance, with a yield of 68.9% in 4 h using molar ratio 400:100:1 (methanol:oil:catalyst). These results evidenced the viability of the use of metallic compounds as catalysts in the obtainment of biodiesel, an interesting alternative to basic and acid catalysis.