Viability of Lactobacillus acidophilus ATCC 4356 incorporated into ice cream using three different methods

Although ice cream is a good vehicle to convey probiotics to human hosts, probiotics are not stable in ice cream because of milieu conditions, species- and product-related properties. Studies on the incorporation of probiotics into ice cream have been conducted; however, there is a need for development of a production method in which probiotics maintain their viability and the physicochemical properties of ice cream are preserved. In this study, the aim was to compare the physicochemical properties of ice cream containing Lactobacillus acidophilus (ATCC 4356) that was incorporated using different methods, as well as to determine the viability of L. acidophilus in the samples. Ice cream was produced using three methods: method 1, ice cream mix was fermented with L. acidophilus prior to freezing; method 2, milk (10% of total milk used in the preparation of ice cream mix) was taken and subsequently fermented with L. acidophilus; the fermented milk was introduced to the remaining ice cream mix prior to freezing; and method 3, L. acidophilus was added to the ice cream mix and the mix was not fermented with L. acidophilus prior to freezing. The viability of L. acidophilus in ice cream was better for methods 1 and 2 of ice cream production when compared to method 3. The viable counts after 90 days of storage were higher than the target level (> 10(6) cfu.g(-1)) only in samples produced using methods 1 and 2.