Abstract:

To investigate the extraction method of total flavonoids from quinoa seedlings, the change of its content during growth, as well as its antioxidant activity and inhibition effect on XOD, the total flavonoids from quinoa seedlings at different growth stages were used as test materials. The total flavonoids of quinoa seedlings were extracted by single factor test combined with response surface optimization ultrasonic method. The optimal extraction conditions were as follows: ethanol volume fraction of 60%, solid-liquid ratio of 1:34, temperature of 20℃, ultrasonic power of 300 W, extraction time of 24 min. The total flavonoid content of quinoa seedlings was the highest at 42 days of growth, which was 26.55 mg/g. The antioxidant activity was the highest at 28 days, and the scavenging capacity of hydroxyl free radical, ABTS free radical and DPPH free radical were 9.76%, 60.50 mg/g and 16.28 mg/g, respectively. The inhibitory effect of the total extract of quinoa seedlings on XOD gradually increased with increasing concentration, with a half-inhibitory concentration (IC₅₀ value) of 5.27 mg/mL. This study provided the extraction method and reference for the development and functional component research of new quinoa seedling products for antioxidation and hyperuricemia prevention.

Key words: quinoa seedlings, total flavonoids, response surface, antioxidant activity, xanthine oxidase