Topic
Black rice
About: Black rice is a research topic. Over the lifetime, 2548 publications have been published within this topic receiving 20840 citations. The topic is also known as: purple rice.
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TL;DR: A decrease in the color intensity was observed when pH values were changed while anthocyanins were reversible in the process of protonation/deprotonation and the addition of glucose, phytic and gallic acids in the optimized extract exposed to light displayed an intermolecular copigmentation.
148 citations
TL;DR: Non-pigmented rice had no detectable conjugated protocatechuic and 2,5-dihydroxybenzoic acids both of which were found in black and red rice, respectively, andTPAC was positively correlated with a∗ (P<0.01), while TPAC was negatively correlated with L∗, b ∗, C and H° values.
142 citations
TL;DR: The inhibitor of tyrosinase activity in black rice bran was investigated and protocatechuic acid methyl ester was identified as an inhibitor in the ethyl acetate fraction by silica gel column chromatography.
Abstract: The inhibitor of tyrosinase activity in black rice bran was investigated. The methanol extract from black rice bran was re-extracted with hexane, chloroform, ethyl acetate, or water. The ethyl acetate extract had the most potent inhibition against tyrosinase activity by 80.5% at a concentration of 0.4 mg/mL. Inhibitory compound in the ethyl acetate fraction was isolated by silica gel column chromatography, and identified as protocatechuic acid methyl ester (compound 1) by GC, GC−MS, IR, and 1H and 13C NMR spectroscopy. Compound 1 inhibited 75.4% of tyrosinase activity at a concentration of 0.50 μmol/mL. ID50 (50% inhibition dose) value of compound 1 was 0.28 μmol/mL. To study the structure−activity relationship, protocatechuic acid (2), vanillic acid (3), vanillic acid methyl ester (4), isovanillic acid (5), isovanillic acid methyl ester (6), veratric acid (7), and veratric acid methyl ester (8) were also assayed. Keywords: Black rice bran; tyrosinase activity; protocatechuic acid methyl ester; structure−...
141 citations
TL;DR: In this article, the authors studied the phenolic compounds identified in rice, their antioxidant activity and their potential beneficial effects on health, such as reduction of oxidative stress, aid in the prevention of cancer, cardiovascular diseases and complications of diabetes, among others.
Abstract: The aim of this work was to study the phenolic compounds identified in rice, their antioxidant activity and their potential beneficial effects on health. In vitro and in vivo studies evaluating the rice grains with different pericarp colour (light brown, red and black) showed potential beneficial effects on health related to the polyphenol content of the grain, such as reduction of oxidative stress, aid in the prevention of cancer, cardiovascular diseases and complications of diabetes, among others. Key words : rice, red rice, black rice, polyphenols, antioxidant, biological effect * Author for correspondence: melmelissaw@hotmail.com INTRODUCTION Several studies have demonstrated the importance of diet in the control of chronic diseases, such as cancer and cardiovascular problems (Birt et al., 2001; Kris-Etherton et al., 2002; Stanner et al., 2003; Houston, 2005). The consumption of fruits, legumes, vegetables and whole grains results a reduced risk of developing these diseases. This could be attributed to the presence of natural antioxidants in these foods, such as ascorbic acid, tocopherols, carotenoids and phenolic compounds (polyphenols) (Melendez-Martinez et al., 2004; Choi et al., 2007), besides other bioactive compounds. Among the compounds with antioxidant activity, polyphenols are important. These are found in a great variety of foods, such as apples, mulberries, cherries, grapes, raspberries, citric fruits, onions, spinach, peppers, oat, wheat, black tea, wine and chocolate, among others (Holden et al., 2005; Dimitrios, 2006). These compounds have demonstrated higher in vitro antioxidant capacity than other antioxidants, such as ascorbic acid and α-tocopherol (Pulido et al., 2000), emphasising the importance of polyphenols as antioxidants in the diet. Although polyphenols are found in several foods, variation is observed in the concentration and type of these compounds due to genetic and environmental factors and processing conditions (Kris-Etherton et al., 2002). Hence, the concentration of phenolic compounds varies greatly among the diets, depending on the type and quantity of food consumed. Rice, being one of the most produced and consumed cereals in the world, has an important role in the relation between the diet and health. Several compounds with antioxidant activity have been identified in rice, including phenolic compounds, tocopherols, tocotrienols and γ-oryzanol (Iqbal et al., 2005). The phenolic
138 citations
TL;DR: It is demonstrated that AEBR has a beneficial effect in reducing the adverse effect of alcohol, and Rats treated with AEBR showed a better profile of the antioxidant system with normal glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and glutathion S-transferase (gST) activities.
Abstract: The study evaluated the protective effect of anthocyanin-rich extract from black rice (AEBR) on chronic ethanol-induced biochemical changes in male Wistar rats. Administration of ethanol (3.7 g/kg/...
134 citations