Effects of Fat Substitute on Survived Probiotic Bacteria in Yoghurt Ice Cream

Abstract

The objective of this research was to compare amounts of fat substitutes supplied in the industries in order to determine their ability to encapsulate probiotic microbes in the production of yoghurt ice cream to ensure maximum survived probiotic microbes. In this research, two fat substitutes, Purity SM 100 and CRYSTAL texTM 648, were used to substitute skim milk in the standard formulas in order to study numbers of survived probiotic microbes and to test the sensory acceptance. For the sensory acceptance, it was found that the probiotic yoghurt ice cream containing 20% Purity SM100 is acceptable at the maximum significance (p ≤ 0.05) because its flavor and taste was better than other samples as well as the best overrun with statistical significant differences (p ≤ 0.05). However, by addition of both fat substitutes at different concentrations, pH values of probiotic yoghurt ice cream products did not have statistical significant differences (p ≥ 0.05). When Lactobacillus acidophilus, Bifidobacterium, and Streptococcus thermophilus microbial starters were added into the probiotic yoghurt ice cream using both fat substitutes in place of skim milk at ratios of 10%, 15%, and 20%, respectively, under a storage condition of -20oC for 4 weeks, it was found that types and amounts of fat substitutes affected the surviving rate of probiotic microbes in the product with a statistical significance (p ≤ 0.05). The addition of fat substitutes, Purity SM100 and CRYSTAL texTM 648, at all concentration levels made probiotic microbes survived in the product, which illustrated that both fat substitutes used in above experiments could encapsulate probiotic microbe cells. The survived probiotic microbes were in the range of 107 – 108 CFU/ml in comparison to the probiotic yoghurt ice cream with the standard formula without the addition of fat substitutes that has survived probiotic microbes of only 106 CFU/ml.