Phenolic Compounds and Bioactivities of Pigmented Rice

Abstract

The pigmented rice has been consumed in China, Japan, and Korea for a long time. It has been used for strengthening kidney function, treating anemia, promoting blood circulation, removing blood stasis, treating diabetes, and ameliorating sight in traditional Chinese medicine. The extracts from pigmented rice are used as natural food colorants in bread, ice cream, and liquor as well as functional food. The pigmented rice is mainly black, red, and dark purple rice, and contains a variety of flavones, tannin, phenolics, sterols, tocols, γ-oryzanols, amino acids, and essential oils. Anthocyanins are thought as major functional components of pigmented rice. Several anthocyanins have been isolated and identified from the pigmented rice, including cyanidin 3-glucoside, cyanidin 3-galactoside, cyanidin 3-rutinoside, cyanidin 3,5-diglucoside, malvidin 3-galactoside, peonidin 3-glucoside, and pelargonidin 3,5-diglucoside. This review provides up-to-date coverage of pigmented rice in regard to bioactive constituents, extraction and analytical methods, and bioactivities. Special attention is paid to the bioactivities including antioxidant and free radical scavenging, antitumor, antiatherosclerosis, hypoglycemic, and antiallergic activities.

Variation of grain nutritional quality among Thai purple rice genotypes grown at two different altitudes

“…A previous investigation reported that tannin concentration, phenolic content and antioxidant efficiency among 133 coloured rice genotypes tested were independent of seasonal changes when grown in different years at the same altitude 22 . In contrast, the variation in altitude effect on the monomeric anthocyanin (a water soluble form of anthocyanin and considered as the primary bioactive compound in purple rice 3,23,24 ) of different purple rice genotypes found here suggested a much larger environmental effect than the previous study. It remains to be elucidated whether the effect is the result of differences in the soil or micro-climate due to 500 m difference in elevation.…”

“…Traditional medicine in China uses pigmented rice to prevent anaemia and to improve blood circulation, kidney function, and eyesight 3 . Black rice porridge is given to aid recovery of invalids; one Chinese genotype is known as "healing of broken bones" 4 .…”

The In-vitro Antibacterial Effect of Colored Rice Crude Extracts against Staphylococcus aureus Associated with Skin and Soft-Tissue Infection

“…flavones, anthocyanins, tannin, phenolics, sterols, tocols, γ-oryzanols, amino acids, and essential oils (Chakuton, Puangpronpitag, & Nakornriab, 2012;Deng et al, 2013). Several phenolic compounds of colored-rice have been reported on the antioxidant and anti-inflammatory properties, both in vitro and in vivo (Fujita, Fujitake, Kawakami, & Nomura, 2010;Muntana & Prasong, 2010;Toyokuni et al, 2002).…”

Enzymatic processing of pigmented and non pigmented rice bran on changes in oryzanol, polyphenols and antioxidant activity

“…Phenolic and flavonoid compounds in rice bran have antioxidative, antimutagenic, and anticancer potential (Nam et al 2005) that play a significant role in maintaining health. Recent studies also showed that pigmented rice bran has biopotent activities including the amelioration of iron deficiency, antioxidant, anti-carcinogenic, anti-atherosclerotic and antiallergic properties (Deng et al 2013). Rice bran nutraceutical properties can hence be exploited for the preparation of functional foods.…”