Effect of Co-Fermentation of Saccharomyces boulardii CNCM-I745 with Four Different Probiotic Lactobacilli in Coffee Brews on Cell Viabilities and Metabolic Activities
Mei Zhi Alcine Chan, Li Tan, Shermaine Wan Qing Heng, Shao‐Quan Liu
Abstract
Amid trends in non-dairy probiotic foods and functional coffees, it is timely to develop a high-count probiotic, fermented coffee beverage. Here, we aimed to enhance the viabilities of different probiotic lactobacilli strains in coffee brews by co-culturing with the probiotic yeast, Saccharomyces boulardii CNCM-I745. The growth, survival, and metabolic activities of Lactiplantibacillus plantarum 299v, Lactobacillus acidophilus NCFM, Limosilactobacillus fermentum PCC, and Lactobacillus gasseri LAC-343 were monitored when cultured individually or co-cultured in coffee brews with S. boulardii CNCM-I745. In co-cultures, all four probiotic lactobacilli maintained viable populations above 5.5 Log CFU/mL for at least 6 months at 4 and 25 °C. In contrast, singly cultured lactobacilli populations generally could not be detected beyond 3 months of storage at either temperature. In co-cultures, vigorous nutrient uptake (glucose, glutamate, and alanine) by the yeast limited lactic acid accumulation by the lactobacilli. Co-culturing also led to accumulations in yeast-derived metabolites (ethanol, 2/3-methylbutanol, 2,3-dimethoxystyrene, and decanoic acid), and lactobacilli-derived metabolites (4-ethylphenol), but the coffee bioactive components (caffeine, trigonelline, and 5-O-caffeoylquinic acid) and antioxidant capacities were maintained. Overall, S. boulardii CNCM-I745 is effective in enhancing the viabilities of probiotic lactobacilli from different species, which may be useful in developing shelf-stable probiotic foods.