Chapter 19: Rice Bran and Oil

Phytochemicals and antioxidant properties of solvent extracts from Japonica rice bran

“…Generally, hexane is traditionally preferred for rice bran oil extraction for cost consideration (Orthoefer & Eastman, 2004). However, it is a worse solvent than MeOH, EtOAc, ethanol (in this study; Renuka Devi & Arumughan, 2007) and isopropanol (Chen & Bergman, 2005;Hu et al, 1996) for extracting antioxidative phytocompounds from rice bran.…”

“…This can be attributed to the amphipathic characteristics of tocopherols, tocotrienols, or oryzanols, involving the methyl groups on a chroman ring and the hydroxyl groups on an aromatic ring of vitamin E homologs, or the carboxylic group on a ferulated moiety, long side chain, and methyl groups on a hydropyrano moiety and sterol of oryzanols (Chen & Bergman, 2005;Godber & Juliano, 2004). In addition to the extraction solvent, the other factors influencing the product composition and antioxidant activity may include stabilisation temperature for raw rice bran , oil refining treatment (Orthoefer & Eastman, 2004;Rogers et al, 1993), rice cultivars and milling time (Chen & Bergman, 2005;Godber & Juliano, 2004;Lloyd et al, 2000), and cultivated environment for rice (Bergman & Xu, 2003).…”

“…Rice bran contains a significant amount of natural phytochemicals such as oryzanols, tocopherols and tocotrienols that have been reported as the strongest antioxidants in rice bran (Godber & Juliano, 2004;Godber & Wells, 1994;Orthoefer & Eastman, 2004). The tocopherols and tocotrienols can be used as radical scavengers, terminating the propagation of radical chain reactions by reacting with peroxyl radicals and generating unreactive phenoxyl radicals as well as hydroperoxide products (Kitts, 1997).…”

Changing flour functionality through physical treatments for the production of gluten-free baking goods

“…Thermal treatments are also usually necessary in flours with high fat content, such as oat (Decker et al, 2014) or whole grain flours, especially whole rice flours (Orthoefer and Eastman, 2004), with the aim of inactivating enzymes which foster rancidity phenomena such as lipases and lipoxygenases. Those high amounts of lipids and lipid-metabolizing enzymes may lead to a reduced shelf life of these flours, and to a decrease in bread-making quality (Tait and Galliard, 1988), sensory acceptability (Galliard and Gallagher, 1988;Hansen and Rose, 1996), and nutritional value (Pomeranz, 1992) of gluten-free products.…”

Rice Bran Oil’s Role in Health and Cooking

“…22 Such enzymes include α-amylase, β-amylase, ascorbic acid oxidase, catalase, dehydrogenase, cytochrome oxidase, esterase, deoxyribonuclease, flavin oxidase, α-and β-glycosidase, invertase, lecithinase, lipase, pectinase, lipoxygenase, peroxidase, phosphatase, phytase, proteinase, and succinate dehydrogenase. However, the most important ones affecting the destabilization of rice bran are lipase, lipoxygenase, and peroxidase.…”