Physiochemical, Texture Properties, and the Microstructure of Set Yogurt Using Whey Protein-sodium Tripolyphosphate Aggregates As Thickening Agents

Background: Polymerized whey protein-sodium tripolyphosphate can be induced to gel in an acidic environment provided during fermentation. The variety of thickening agent has an influence on texture that is an essential aspect of yogurt quality affecting consumer preference. Similar to polysaccharide stabilizers, the cold gelation properties of whey proteins can improve the body texture of yogurt products. Polymerized whey protein-sodium tripolyphosphate could be a favorable and interesting thickening agent for making set yogurt.

Results: The effects of whey protein isolate (WPI), heat-treated whey protein-sodium tripolyphosphate (WPI-STPP), heat-treated WPI and pectin on the storage properties and microstructure of yogurt were investigated. All samples were analyzed for syneresis, pH, titratable acidity, viscosity, texture profile and microstructure during storage. The results showed that incorporating heat-treated WPI-STPP had a significant impact on syneresis (32.22 ± 0.60), viscosity (10 956.67 ± 962.1) and hardness (209.24 ± 12.48) (p < 0.05) with uniform body texture.

Conclusion: Yogurt fermented with modified WPI-STPP had higher levels of protein and better hardness compared with yogurt using pectin. The microstructure was observed to be a uniform and denser, complicated network. Heat-treated WPI-STPP may be useful for improving yogurt texture. © 2016 Society of Chemical Industry.