Effects of Partial Replacement of Sugar with Fig Syrup on the Survival of Bacillus coagulans and the Physicochemical Properties of Probiotic Ice Cream

RESEARCH BACKGROUND: Various sectors of the food industry demand the enrichment of food with functional compounds. Probiotic products with valuable nutritional and therapeutic properties have attracted great attention in the fields of industry, nutrition and medicine. The aim of the present study is to investigate the sensory and physicochemical properties of probiotic ice cream containing fig syrup and to evaluate the survival of Bacillus coagulans after 90 days of storage at -18 °C. EXPERIMENTAL APPROACH: In this study, four experimental groups of ice cream were produced as follows: plain dairy ice cream (without additives), ice cream containing 10(9) CFU/g B. coagulans, ice cream containing 25 % fig syrup as sugar substitute and ice cream containing 25 % fig syrup as sugar substitute and 10(9) CFU/g B. coagulans. They were stored at -18 °C for 3 months. Texture, pH, acidity and viscosity were analysed and microbial counts were determined after 1, 30, 60 and 90 days of storage. The organoleptic evaluation was carried out on days 1 and 90. RESULTS AND CONCLUSIONS: The results showed that during the initial freezing process and the transformation of the mixture into ice cream, the number of B. coagulans decreased from 10(9) to 10(7) CFU/g, without significant changes observed over the 90-day period. No significant changes were found in the sensory and textural properties of the samples either. Replacement of 25 % sugar with fig syrup reduced the pH, increased the acidity of the ice cream and improved their viscosity. In conclusion, the production of functional ice cream using fig syrup and B. coagulans is recommended for their health benefits. NOVELTY AND SCIENTIFIC CONTRIBUTION: The results of this study can be used to prepare functional and healthy foods. Our results suggest that fig syrup has the potential to be used as a natural sweetener or sugar substitute in various products.