Study on Physicochemical Properties, Antioxidant Activity and Flavor Quality in the Fermentation of a Plant-Based Beverage by Different Lactic Acid Bacteria

This study investigated the effects of three different lactic acid bacteria (LAB) strains (<i>Limosilactobacillus fermentum</i> 14, <i>Limosilactobacillus reuteri</i> 18, and <i>Lactiplantibacillus plantarum</i> CAU808) on the nutrient components, bioactivity, and flavor profiles of a medicinal and edible homologous (MEH) plant-based beverage (QJ). Results demonstrated that QJ served as an excellent substrate for LAB growth, with viable counts of all three LAB exceeding 8.5 log CFU/mL after fermentation. Fermentation significantly reduced soluble sugar contents while increasing organic acids levels. A slight enhancement in ABTS radical scavenging capacity was also observed. Electronic tongue (E-tongue) analysis revealed that LAB fermentation markedly decreased bitterness and enhanced sourness, sweetness, and umami, thereby improving the overall taste profile. Furthermore, electronic nose (E-nose) and HS-SPME-GC-MS analyses indicated distinct alterations in odor characteristics post-fermentation. A total of 87 volatile compounds were identified, with alcohols constituting the predominant group. Compared to the other two strains, <i>Lactiplantibacillus plantarum</i> CAU808 demonstrated superior fermentation performance and more favorable flavor characteristics. These findings provide a theoretical basis for utilizing LAB fermentation to optimize the flavor of MEH plant-based beverages.