Technological functions of hydrolyzed whey concentrate in ice cream

Introduction. The article examines the quality indicators of low-fat ice cream with a different ratio between sugar and hydrolyzed and non-hydrolyzed concentrates of demineralized whey.Materials and methods. The degree of lactose hydrolysis was determined by iodometric and refractometric methods, the water activity in the mixtures was determined using the water activity analyzer, the rheological characteristics were determined using a rotary viscometer, the foam overrun and foam stability of the ice cream mixtures and the melting rate of ice cream were determined using modified methods, sensory indicators were determined using the descriptive-integral method. The mass fraction of protein, dry matter, overrun, resistance to melting in ice cream were determined using well-known methods.Results and discussion. Based on the calculation of the degree of sweetness of whey concentrates, taking into account the mass fraction of total solids, the degree of lactose hydrolysis and the known values of the relative sweetness of sugar, lactose, glucose and galactose, a concentrate with a solids content 40% was chosen for use in the ice cream formulation. According to the results of the study of the quality indicators of ice cream mixtures, it was found that the hydrolyzed concentrate of demineralized whey with a mass fraction of solids 40% could replace up to 42% of sugar in the composition of ice cream, while maintaining the degree of sweetness determined for this type of ice cream in the range from 0.8 to 0.9. According to the viscosity-speed characteristics, the mixture of low-fat ice cream with a concentrate of hydrolyzed demineralized whey is classified as a system with a pronounced coagulation structure with the detection of thixotropic properties. Ice cream based on hydrolyzed whey concentrate contains 3.3% of whey proteins, which corresponds to the standard chemical composition of ice cream. The high content of lactose hydrolysis products in ice cream increases overrun, but reduces the resistance to melting of ice cream, which must be taken into account during the technological process and when choosing a consumer container.Conclusions. The feasibility of using a hydrolyzed whey concentrate with a mass fraction of solids 40% as a sweetening and protein-containing ingredient in low-fat ice cream has been proven.