Effects of germination on the physicochemical properties, in vitro starch digestibility, and antioxidative activity of white quinoa (Chenopodium quinoa willd.)

Abstract

White quinoa (Chenopodium quinoa Willd.) seeds were subjected to germination at 25°C for 2 days and subsequent freeze-drying, and the effects of germination on the physicochemical properties, in vitro starch digestibility and antioxidative activity were evaluated. Germination decreased the crude protein, crude fat, and crude ash contents but increased slightly the total carbohydrate content, including starch. The total phenolic contents in water and 80% ethanol extract of quinoa were increased during a 48 h germination period, whereas the total flavonoid contents were decreased slightly. The pasting properties determined using Rapid Visco Analyser (RVA) showed that germination process decreased the pasting viscosities of quinoa significantly, due to the increased amylolytic activities. In vitro starch hydrolysis (%) of germinated quinoa was somewhat higher than that of raw quinoa. The antioxidative activity (1,1-diphenyl-2-picrylhydrazyl assay) of germinated quinoa was slightly lower than that of raw quinoa. These results suggest that bioactive components and biological activities may vary according to the structural parts of germinating quinoa seed. © 2018, Korean Society of Food Science and Nutrition. All rights reserved.