Targeted metabolomics of phenolic and volatile compounds during the fermentation of a potential probiotic tofu whey beverage

Abstract

Tofu whey is a rich source of nutrients and can be biotransformed into functional beverages. This study assessed the fermentation of this by-product by Lactiplantibacillus plantarum BL011 and Kluyveromyces marxianus B0399, analysing cell viability, metabolite production, sugar consumption, and isoflavone concentration. Targeted metabolomics approach was employed to characterise changes in phenolic and volatile compounds during fermentation, combined with principal components analysis (PCA). Additionally, toxicological effects were evaluated in C. elegans. The co-culture's effectively metabolised sugars and increased isoflavone aglycones concentration. Fermentation also reduced the beany flavours from tofu whey and increased the diversity and concentration of fruity esters, such as ethyl acetate and 2-phenylethyl acetate. PCA revealed that fermentation influenced metabolite composition of whey. Four metabolites were selected as relevant for sample clustering: lactic acid, 2-methyl butanol, glucose, and acetic acid. The study presents a sustainable and innovative solution for the reuse of whey and generation of novel plant-based foods.