Analysis of antioxidant activity of quinoa liquor with different processes based on electron spin resonance technology

In order to study the differences in antioxidant activity of quinoa liquor with different processes, the effects of quinoa liquor with different processes on 1,1-diphenyl- 2-picrylhydrazyl (DPPH) radicals, superoxide anion radicals and hydroxy radicals scavenging capacity were studied by electron spin resonance (ESR) technology. On this basis, the antioxidant activity of quinoa liquor produced by 4 processes was determined. The results showed that the ESR signal intensity was well correlated with the free radical concentration and was not affected by the color of the sample, which was suitable for the detection of antioxidant activity of quinoa liquor. The optimal dark reaction time of quinoa liquor for DPPH radicals, hydroxy radicals, and superoxide anion radicals was 40 min, 100 min and 10 min, respectively. In the above optimal dark reaction time, 4 kinds of quinoa liquors had the ability to clear the above free radicals, the clearance rates from large to small were as follows: superoxide anion radical>DPPH radical>hydroxyl radical. The clearance abilities of 4 kinds of quinoa liquors for radicals from strong to weak were as follows: string steamed quinoa liquor>blended quinoa liquor>fermented quinoa liquor>quinoa liquor mixed with Jiuzao.