STUDIES ON THE STABILITY OF FERMENTED MILK BEVERAGE BY THE ADDITION OF WHEY PROTEIN CONCENTRATE

Whey protein concentrate (WPC) was widely used in fermented milk beverage (FMB). The effects of different contents and addition time of WPC on particle size, zeta-potential, surface hydrophobicity, microstructure and rheological properties of FMB were investigated. When WPC was added and fermented in FMB, the particle size and microstructure had little change, while zeta-potential decreased and surface hydrophobicity increased gradually during acidification. However, when WPC was added after fermentation, the process of acidification caused a pronounced alteration in the stability of FMB. It was also shown that FMB with WPC added after fermentation was pseudoplastic. The consistency coefficient decreased and the flow behavior index increased when the content of WPC increased in the FMB system fermented with WPC during acidification. These results could have important theoretical and practical implications in the addition of WPC based on FMB. PRACTICAL APPLICATIONS This study investigated the effects of different contents and addition time of whey protein concentrate (WPC) in fermented milk beverage (FMB) on particle size, zeta-potential, surface hydrophobicity, microstructure and rheological properties. The information on the stability of FMB when WPC was added could shed light on the technological application and reduce the business costs. The research on the properties of FMB via adding WPC would provide a theoretical basis and technical guidance for production.