Sensory evaluation of a novel sustainable probiotic beverage based on tofu whey

Abstract

Abstract The reuse of agro-industrial residues aligns with sustainability purposes and the circular economy; in this context, tofu whey - a nutrient-rich by-product of tofu production - is a promising substrate for functional beverages. This study aimed to assess the sensory attributes of a potential probiotic plant-based beverage from tofu whey fermented using Lactiplantibacillus plantarum and Kluyveromyces marxianus. The strains were cultivated separately and inoculated at 1×106 CFU/mL, followed by 48 h of co-culture fermentation at 37 °C. Samples were analyzed for pH, microbial growth, and metabolites via HPLC. Formulations were prepared with concentrated apple juice or demerara sugar and compared to non-fermented tofu whey in a sensory evaluation with 98 panelists. Fermentation reduced the pH from 5.92 to 3.95, promoted acetic acid production, and consumed residual sugars, while inhibiting ethanol formation. Beverages with demerara sugar presented the highest sensory acceptance due to their balanced sweetness and smoothness, whereas apple juice formulations were moderately rated. The results suggested that enhancing sweetness and texture while minimizing acidity and bitterness can improve acceptance, demonstrating tofu whey’s potential as a sustainable and functional ingredient for innovative plant-based beverages.