Analysis of key enzyme activity and aroma volatile compounds in microwave-irradiated quinoa during storage

Abstract

This study investigated the effects of microwave stabilization treatment on the dynamic changes in volatile and flavor compounds in quinoa with different milling degrees. Microwave treatment effectively suppressed enzymatic activity in quinoa, resulting in reduced levels of undesirable compounds such as hexanal, nonanal, and others associated with beany, yeasty, and pungent aromas. The microwave-treated quinoa exhibited a broader array of volatile flavor compounds compared to the hot air-treated quinoa. Additionally, it promoted the formation of furanones and 2-acetylpyrrole, imparting roasted and toasted notes to microwave-treated quinoa. As storage time increased, the content of bitter, aldehydic, and fatty aldehydes significantly rose, while alcohols decreased. Remarkably, esters, ketones, and acids exhibited a sharp increase. Notably, a rapid surge of acetic acid after 6 weeks indicated complete spoilage, with the untreated group displaying more pronounced changes compared to the microwave-treated group. This research demonstrated the promising application of microwave in quinoa with satisfactory flavor preservation and alleviating the deterioration during storage.