The Effect of Whey Protein Concentrates on Technological and Sensory Quality Indicators of Ice Cream

Abstract

The demand for protein-fortified foods is increasing, and so is the necessity of the complete utilization of milk constituents in the food industry. The research objective was to study various technological and sensory indicators of ice cream fortified with whey protein concentrate. The study featured ice cream samples with 8% of mass fraction of fat and 10% of nonfat milk solids with whey protein concentrations of 1–5 %. The dynamic viscosity was studied by rotational viscosimetry, dispersion – by microstructural methods, thermal stability – by thermostatic methods, and titratable acidity – by standard methods. Whey protein concentrate in amount of 1–5 % increased the titratable acidity by 1.05–1.90 times and the dynamic viscosity – by 1.16–2.90 times. With an extra addition of 4% whey protein concentrate, the viscosity of the mix exceeded the technologically permissible values. The consistency coefficient increased by 19.4 times, and the flow index decreased by 4.8 times. During freezing, the mix revealed the high capability to air saturation with mass fraction of melt whey protein concentrate of 1 and 2%. Thermal stability also increased: mass fraction of melt after 60 min of retention decreased by 3 times. After adding 1–3% whey protein concentrate, the dispersion of air bubbles and ice crystals improved. It was determined in accordance with the density of distribution by their sizes. The hardness of ice cream decreased 1.4–8.3 times as whey protein concentrate increased. A greater mass fraction of whey protein enhanced the creamy taste and improved the texture. Based on the main technological and sensory quality indicators, the mass fraction of whey protein concentrates should be under 3%. The results may be used in protein-fortified ice cream production.

Keywords

• ice cream
• acidity
• viscosity
• hardness
• air cells
• ice crystals