4. Conclusions
This study indicates that encapsulation can significantly improve the survival of probiotic bacteria in ice cream. Milk products such as ice cream and frozen desserts may serve as carriers for delivering the probiotic bacteria into the human gut. The high total solids level in ice cream including the fat and milk solids provides protection for the probiotic bacteria. There was a loss of only 0.7 and 0.4 log in the free state of L. casei and B. lactis, respectively, and 0.3 and 0.2 log in the encapsulated state over the first month and 2.7 and 2.5 log in the free state and 1.1 and 0.5 log in the encapsulated state over the subsequent five months, respectively. The final count after 6 months showed a 3.4 and 2.9 log decrease in the free state of L. casei and B. lactis, respectively, compared to
1.4 and 0.7 log in the encapsulated state. The numbers of viable probiotic bacteria in all types of ice cream were between 108 and109 cfu/g at the end of three months of storage which is the normal shelf life of ice cream. This viable cell number is higher than that recommended by the International Dairy Federation (107 cfu/g), indicating that the high initial number of probiotic can provide the recommended number in the final product. Further studies are needed to evaluate the protection effect of microencapsulation on the probiotic survival in the gastrointestinal tract.