Lactic acid fermentation of non-conventional plant-based protein extract

The increasing demand for plant-based foods necessitates the development of effective preservation methods to ensure safety and quality. This study evaluated the effectiveness of biopreservation using eight plant-based protein extracts (PBPEs) (pea, faba, soy, potato, pumpkin, hazelnuts, rice, and hemp) fermented with 12 different lactic acid bacteria (LAB) strains from four species. The effectiveness of LAB biopreservation was assessed both at the endpoint and in real-time using impedometric analysis and was found to depend on both the matrix and the strain. Among the 12 LAB strains, Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus showed the highest adaptability, particularly in soy, faba, and hemp protein extracts, highlighting their potential as effective biopreservative agents for diverse PBPEs. Given the distinctive advantage of biopreservation in enhancing organoleptic properties, this aspect was also evaluated for the two most effective LAB strains. Fermentation with L. delbrueckii subsp. bulgaricus 1932 and L. plantarum 4193 significantly improved the aroma profile of fermented PBPEs (pea, faba, soy, pumpkin, rice, and hemp) where they exhibited the best adaptability. Notably, levels of hexanal and hexanoic acid, compounds often associated with off-flavors, were markedly reduced, enhancing the organoleptic properties of the final products. These findings emphasize the dual benefits of LAB fermentation as a natural preservative and flavor enhancer, with promising implications for its application in the food industry.