Enhancement of nutritional characteristics of Tartary buckwheat (Fagopyrum tataricum) sprouts, passion and pineapple juice fermented by yeast (Saccharomyces cerevisiae) and Lactobacillus plantarum

The study examined the functional properties of lactic yeast-fermented Tartary buckwheat sprout with passion and pineapple juice (Tatary buckwheat sprout juice). Pineapple and passion fruit were included during fermentation to improve the sensory and nutritional quality of the juice. We initially created a juice with Tartary buckwheat sprouts, and then fermented it with Lactobacillus plantarum and yeast (Saccharomyces cerevisiae) to produce a novel fermented sprout juice. Our results indicated that the best organoleptic quality was achieved when the inoculum of Lactobacillus plantarum was 2%, the inoculum of yeast was 1%, and the fermentation time was 30 hours. The results showed that fermentation resulted in a 1.55-fold increase in the total amino acid content, with fresh sweet amino acids increasing by 1.75-fold and sour-bitter amino acids increasing by 1.33-fold. Additionally, the levels of acetic acid, lactic acid, citric acid, and tartaric acid in the buckwheat sprout juice increased by 12.31%, 11.45%, 4.22%, and 3.88%, respectively. GC-MS analysis revealed a significant increase of volatile flavoring substances, such as alcohols and esters, by more than 24.7% in the fermentation products. From the results, yeast-Lactobacillus fermentation process may effectively improve the nutritional values of Tartary buckwheat sprout juice.