Extraction and anti-oxidant characteristics of polyphenols from amaranth seed

Effects of concentration of extraction solvent,ratios of solid to liquid,extraction time and temperature on extraction rate of polyphenols from amaranth seed,and antioxidant characteristics of polyphenols were studied.The results showed that the optimum extraction conditions for polyphenols from Amaranth seed were using water as solvent,with ratios of solid to liquid by 1:30,extracted with ultrasonic wave-assisted at 55℃ for 105 min.Results of the antioxidation indicated that the rate of scavenging DPPH was 52.45% when concentration of polyphenols was 10μg/ml;The inhibitory rate to O2.-was 65.34% when concentration of polyphenols was 60μg/ml;and the inhibitory rate to.OH was 86.29% when concentration of polyphenols was 100 μg/ml,the inhibitory rate to.OH was 4~5 times higher than VC,while concentration of polyphenols was 20~100 ug/ml.