Comparative analysis of physicochemicals and antioxidative properties in new red rice (Oryza sativa L. cv. Gunganghongmi)

Rice antioxidants: phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, γ‐oryzanol, and phytic acid

“…Considerable evidence has accumulated to substantiate the claim that pigmented rice varieties are more phenolic acid-rich compared to nonpigmented rice varieties (Goffman and Bergman 2004;Chi et al 2007;Chung and Shin 2007;Finocchiaro et al 2007;Yawadio et al 2007;De Mira et al 2009;Vichapong et al 2010;Zhang et al 2010;Hirawan et al 2011;Lin and Lai 2011;Massaretto et al 2011;Huang and Ng 2012;Mohanlal et al 2012;Gunaratne et al 2013;Pitija et al 2013;Seo et al 2013). For example, in the bran, the TPC of pigmented rice varieties (sum of black, purple, and red) is 3509 mg GAE/100 g, which is 5.9 times higher than that of nonpigmented rice varieties (596.3 mg GAE/100 g).…”

“…Sixteen methods are routinely used for assessments of the antioxidant activities of rice grains (Table 8). Depending on the reaction mechanisms upon which they operate, these methods can be classified into five groups: (1) those based on the prevention of chain initiation by rice antioxidants, including ORAC, 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activity, and ferrous-iron chelating activity, (2) those based on the inhibition of peroxide formation, including inhibition of linoleic acid autooxidation, (3) those based on the prevention of continued hydrogen abstraction, including inhibition of conjugated diene formation and inhibition of thiobarbituric acid reactive substance (TBARS) formation, (4) those based on reductive capacity, including reducing power, molybdate reduction capacity, FRAP, and DPPH radical scavenging activity, and (5) those based on oxy-radical scavenging, including hydrogen peroxide, hydroxyl radical, superoxide anion, singlet oxygen, tert-butylperoxyl, and peroxynitrite scavenging activities (Kim 2005;Chi et al 2007;Stratil et al 2007;Shen et al 2009;Sangkitikomol et al 2010;Zhang et al 2010;Laokuldilok et al 2011;Min et al 2011;Jun et al 2012;Moongngarm et al 2012;Saikia et al 2012;Cho et al 2013;Gunaratne et al 2013;Seo et al 2013;Walter et al 2013). Each of these assays can independently account for more than one of these mechanisms.…”

Brown Rice Versus White Rice: Nutritional Quality, Potential Health Benefits, Development of Food Products, and Preservation Technologies

“…In another study, BR was found to contain 1.5 mg/g GABA and 0.38 mg/g γ‐oryzanol. However, the total phenolics content of ethanolic extract derived from BR was 11.3 mg gallic acid equivalents/g extract (Seo et al., ). Recently, the total phenolic contents of eight varieties of BR were found in a range from 72.45 to 120.13 mg of gallic acid equiv./100 g. However, the total flavonoids content ranged from 75.90 to 112.03 mg catechin equiv./100 g. Trans‐ferulic acid was the predominant phenolic acid in BR.…”

“…BR and its derived fractions or extracts have shown antioxidant activity based on in vitro assays and in vivo trials (Table ). The in vitro antioxidant activity of BR extracts varied depending on some factors such as extraction method, bioactive compounds content of extract, BR cultivar or variety, and bioactive compounds fraction, bound or free (Gao et al., ; Gong et al., ; Kim et al., ; Seo et al., ; Zhou et al., ). Also, antioxidant activity of BR or its extracts is influenced by pretreatments or processing.…”

“…Generally, higher amounts of nutrients such as protein, fat, vitamins, and minerals were found in BR compared to those in WR. Also, the whole BR grain has shown a greater content of bioactive compounds such as phenolic acids, falvonoids, γ‐oryzanol, aminobutyric acid (GABA), α‐tocopherol, and γ‐tocotrienol (Gong et al., ; Pang et al., ; Seo et al., ). This is because these components are highly concentrated in the outer bran layers of rice grain (Sharif et al., ).…”