Effect of LAB starters on technological and functional properties of composite carob and chickpea flour plant-based gurt

Abstract

Carob pulp powder and chickpea flour were used as ingredients in the formulation of a plant-based fermented beverage (gurt). Three different exopolysaccharide-producing strains (Levilactobacillus brevis AM7, Weissella confusa CK15, and Pediococcus claussenii DSM 14800) were used as starters to obtain a gurt rich in fiber and protein. L. brevis AM7 showed the fastest and more intense acidification, whereas W. confusa CK15 induced the highest viscosity increase (reaching up to 3000 mPa × s) due to the in-situ synthesis of dextran. Gurts were characterized by a high antioxidant activity (86.37 %) mainly due to the ingredients used, since it was not affected by fermentation. Depending on the strain, fermentation determined a significant decrease of gurts starch hydrolysis index. Overall, the microbiological, biochemical, and rheological features were retained during the two-weeks refrigerated storage. All exopolysaccharide-producing strains resulted suitable starters for gurt production, but their metabolic traits reflected different fermentation performances and product features. Overall, W. confusa CK15 resulted an efficient dextran producer whereas, based on the growth and acidification kinetics, L. brevis AM7 showed optimal adaptation to carob/chickpea substrate and pro-technological performance.