Analysis of flavor metabolism characteristics of quinoa (Chenopodium quinoa Willd.) sprout plant beverage by GC-IMS combined with intelligent sensory technology.

After germination and fermentation, the flavor quality of quinoa is significantly enhanced; however, the specific metabolic mechanisms underlying this improvement remain unclear. In this study, the odor, taste, volatile organic compounds (VOCs), and basic physicochemical indexes of samples at 0, 4, 8, and 12 h during quinoa lactic acid bacteria fermentation (QLF) and quinoa sprout lactic acid bacteria fermentation (QSLF) were statistically analyzed to explore the changing patterns of flavor metabolites during quinoa sprout lactic acid fermentation. The results indicated that after 8 h of fermentation, the pH, total acid, total saponins, and amino acids levels in QLF and QSLF stabilized. Germination significantly reduced saponins content, while lactic acid bacteria fermentation replenished amino acids lost during germination. Electronic nose and electronic tongue tests showed that QSLF8 had the best odor and taste. A total of 44 VOCs were identified in the GC-IMS test results, including 20 aldehydes, six esters, 11 higher alcohols, four ketones, and three others compounds. The VOCs content of QSLF group (QSLFA) was higher than that of QLF group (QLFA). The orthogonal partial least squares discriminant analysis (OPLS-DA) model of QLFA and QSLFA, 22 key VOCs-mainly aldehydes and higher alcohols-were identified; of these, 21 exhibited increased, contributing to the enhanced aroma quality of QSLFA. The primary metabolic pathway was phenylalanine metabolism, which influenced fatty acids, amino acids, and carbohydrate metabolism to enhance QSLFA flavor. These findings underpin advanced processing of cereal and pseudocereal-based foods.