Probiotic ice cream: viability of probiotic bacteria and sensory properties

Ice cream is a dairy product with good potential to act as a food carrier for probiotic bacteria. The incorporation of probiotic bacteria into ice cream is highly advantageous since, in addition to making a functional healthy food, ice cream in itself contains beneficial substances such as dairy raw materials, vitamins and minerals, and is consumed by the general population. Also, compared with fermented milks as a vehicle, ice cream supports considerably greater viability of probiotic strains during production and especially storage. However, losses in the viability of probiotic bacteria in ice cream unavoidably occur during product formulation, processing, storage and melting. During these stages, probiotic cells are subjected to different stresses related to pH, acidity, redox potential, freezing, oxygen (especially in overrun processing), sugar concentration and osmotic effects, hydrogen peroxide, antagonistic impact of co-cultures (in fermented ice creams), and mechanical shearing. It seems that the rate of loss of probiotic cells is greater during the freezing process than during storage. Practicing methods such as selection and application of oxygen-resistant probiotic strains, elimination of molecular oxygen (using oxygen-scavenging components, packaging material that is impermeable to oxygen as well as thicker packaging materials and active packaging systems), applying severe heat treatment, using microencapsulation techniques, and adjusting the product formulation (e. g., fortification of milk with nutrients and prebiotics) can increase the viability of probiotics in the final product. Supplementation of ice cream with probiotic bacteria has been found to have little effect on its flavor, texture or other sensory characteristics. There are also many ways to improve the sensory attributes of the product to compensate for any changes that do occur. This article reviews the viability of probiotic bacteria in ice cream and the main methods used to improve their viability and the sensory characteristics of probiotic ice cream.