Effect of prebiotics on thermally acclimatized lactobacilli cultures and their application as synbiotics in RTD fruit drinks.

In this study, the effect of prebiotics such as fructooligosaccharides (FOS), galactooligosaccharides (GOS), isomaltooligosaccharides
(IMO), and inulin on the probiotic biomass and its probiotic properties were studied for thermally acclimatized
Lactobacillus helveticus (H-45) and Lacticaseibacillus casei N (N-45) strains at 45 ℃ using adaptive laboratory evolution
method. Among the prebiotics studied, GOS was found to be more suitable for synbiotic preparation. The tolerance of lactobacilli
cultures H-45 and N-45 in the presence of acid and bile were 4.79 and 8.60% and 2.84 and 4.65% higher than their
wild-type strains (H-37 and N-37). Similarly, H-45 and N-45 showed an increase in survivability of 5.29 and 8.63% under
simulated gastric conditions and 9.21 and 7.70% under simulated intestinal conditions than H-37 and N-37. Propionic acid
yield increased by 0.65-fold in N-45 compared to N-37 in the presence of GOS as a prebiotic, whereas H-37 showed 0.26-
fold higher propionic acid production than H-45. Thermally acclimatized strain N-45 showed better survivability under stress
conditions than H-45. The synbiotic combination of N45 + GOS was spray-dried using corn starch (CS) as carrier material
to obtain spray-dried synbiotic powder (N45 + CS + GOS). This synbiotic powder was added to the ready-to-drink (RTD)
fruit drinks prepared from five fruit-flavoured squashes (pineapple, orange, grape, mango, and lemon ginger). The varied
amounts of added synbiotic powder did not significantly alter the physicochemical properties of the fruit drinks. Hence,
synbiotic formulation N45 + GOS + CS may find application in developing various functional foods.