Effect of temperature and gelling agents on stability of whey protein isolate based gels

Whey proteins from bovine milk are of high quality and their incorporation into the diet can improve the health status of individuals. Chewy gels with a variety of colours and sour or sweet flavours appeal to all age groups. Hence gels can be used as a delivery system of proteins and other nutrients in the diet provided their stability is maintained. Apart from attracting customers, whey protein-based gels would be an excellent means to provide high-quality proteins with all essential amino acids. Hydrocolloids like gelatine, carrageenan, and agar agar were used as gelling agents in the study. The effect of four different temperatures on hydrocolloid gels was analysed (20 °C, 25 °C, 30°C and 35°C). A ten member sensory panel evaluated the samples based on a nine point hedonic scale. Among the different gelling agents gelatine gel was found to have the lowest melting point of approximately 30 °C. Carrageenan and agar agar gel were stable even at 35 °C. They measured higher melting points than gelatine and were stable at room temperature. The highest acceptability sensory score was for the agar agar-based gels. Gelatine being sensitive to moderate temperature and being of animal origin affects consumer acceptability. Hence, agar agar was found to be the best hydrocolloid for formulating whey protein isolate gels based on sensory score and gel stability at room temperature.