Effects of fermentation by Bifidobacterium bifidum on the rheology and physical properties of ice cream mixes made with cow and vegetable milks

Summary Fermented and nonfermented probiotic ice creams were made by incubating Bifidobacterium bifidum (Bb‐12) culture in ice cream mixes with cow, soya, coconut and composite milks (combinations of coconut or cow milks with soya milk). The changes in ice cream‐eating qualities and physical properties (melting rate, apparent viscosity, hysteresis, fat globule size, zeta potential, microscopic structure and freezing behaviour) were evaluated. In general, fermentation decreased the melting rate and total acceptability of ice creams but increased the apparent viscosity, hysteresis, particle size and freezable water. For fermented ice creams containing composite milk, those containing cow milk showed a higher percentage change than those containing coconut milk in respect of hysteresis, particle size and freezable water; however, the apparent viscosity was not affected. Effect of fermentation on non‐Newtonian behavior (i.e. their viscosity decreases with increasing shear rate) of ice creams.