Effects of different processing methods on physicochemical and microbiological properties of kefir ice cream

Abstract

In this study, kefir ice cream was produced using two different methods. In method 1, the ice cream mixture was incubated with kefir starter culture until a pH value of 6.1 or 5.5 was reached, and in method 2, the ice cream mixture was blended with kefir to reach a pH value of 5.5 or 6.1. Kefir ice cream produced by method 2 had a higher overrun and lower firmness than that produced by method 1. When comparisons were made based on the pH value of the ice cream mixture, kefir ice cream produced from the ice cream mixture with a pH of 6.1 instead of 5.5 had a higher overrun and melting rate and a lower firmness. The slightly higher counts on MRS agar, M17 agar, MSE agar, DSM 254 medium, and YGC agar were determined in the kefir ice cream samples produced by method 1 or produced from an ice cream mixture with a pH of 5.5. Although it is unknown if the number of bacteria on MRS agar detected in the samples, where the number was greater than 6 log cfu g⁻¹ even after 90 days of storage, are probiotics or not, kefir ice cream has the potential to be a probiotic product. In this study, it has been demonstrated that kefir ice creams with different physicochemical and microbiological properties can be produced by altering the ice cream production method and pH value of the ice cream mixture.