Antimutagenic properties of several kinds of rice as tested upon yeast strain Saccharomyces cerevisiae D7

摘要

The aim of this work was to study antimutagenic and antioxidant properties of water extracts of various types of rice. Antioxidant activity, total phenolic andflavonoid contents were measured spectrophotometrically. Individual phenolics — catechins, catechin gallates, ferulic acid — were analysed by HPLC/PDA. Antimutagenic activity of rice extracts was tested using unicellular eukaryotic yeast strain Saccharomyces cerevisiae D7 the first time.Non-processed rice types contained substantially higher amount of soluble total and individual phenolics and had higher antioxidant activity than peeled rice. Parboiled rice, in which technological processing helps to maintain active substances inside the grains, exhibited also relatively high phenolic levels. The highest antimutagenic effect was proved in Indian Rice, Arborio, Jasmine Rice and Three Colours Rice independently of rice extract concentration. Because of relatively high values of phenolics and high antioxidant activity, the antimutagenic activity of these samples could be attributed to biologically active phenolics present mainly in the bran layer of whole rice grain.