Influences of lactose hydrolysis of milk and sugar reduction on some physical properties of ice cream

Existence of lactose in ice cream induces lactose intolerance and alpha-lactose crystals. These issues can be overcome by complete or partial elimination of lactose in milk. Therefore, in this research pasteurized milk was hydrolyzed (LH = 0, 25, 50, 75, and > 75 %) and its effects along with sugar reduction (SR = 0, 25, 50 %) were investigated on some properties of mix and frozen ice cream. The hydrolysis level was determined by freezing point, chloramine T, and HPLC. Results showed that with increasing LH, the apparent viscosity increased, freezing point decreased, while surface tension and density were constant in mixes. In contrast, in frozen ice creams the hardness, and resistance to melting decreased but stickiness increased (p < 0.05). Moreover, in low sugar and low lactose ice creams the hardness and sweetness decreased but resistance to melting increased. In general, the ice creams with SR = 25 % and LH = 75 % showed the highest similarity to control in terms of physicochemical as well as sensory properties.