Effect of pressure cooking on phenolic compounds of quinoa

Due to good nutritional properties and potential health benefits, quinoa has gained an increasing attention. The study aimed to analyze the effect of pressure cooking on the composition, antioxidant activity, antibacterial activity and bioavailability of phenolic compounds in four types of quinoa, and to evaluate the correlation between phenolics and its biological activities by correlation analysis. The results showed that different varieties of quinoa contained different phenolic components and their biological activities were different. Pressure cooking could significantly increase (P < 0.05) the phenolic contents of quinoa, and decrease in vitro digestibility of protein. The antioxidant activity, antibacterial activity and bioavailability of quinoa were also enhanced which were positively related with phenolic contents. HPLC analysis indicated that at least twelve phenolic compounds were found in quinoa, and hyperoside, sinapic acid, rutin and ferulic acid occupied a majority of them. Correlation analysis suggested that hyperoside, quercetin, sinapic acid, ferulic acid and gallic acid made the key contribution to antioxidant and antibacterial activities of phenolic compounds of quinoa. The results provided valuable information for quinoa processing with phenolics as functional ingredient.