Comparison of Texture of Yogurt Made from Conventionally Treated Milk and UHT Milk Fortified with Low‐heat Skim Milk Powder

The textures of yogurt made from ultra‐high temperature (UHT) treated and conventionally treated milks at high total solids were investigated. The yogurt premixes, fortified with low‐heat skim milk powder to 16%, 18%, and 20% total solids, were UHT processed at 143°C for 6 s and heated at 85°C for 30 min using the conventional method. The onset of gelation was delayed in the UHT‐processed milk compared with conventionally heated milk. During fermentation, the viscosity of yogurt made from UHT‐treated milk at 20% total solids was close to that of yogurt made from conventionally treated milk with 16% total solids. However, after storage for ≥ 1 d, the yogurt made from UHT‐treated milk had lower viscosity and gel strength than the yogurt made from conventionally treated milk. The solids level had no influence on yogurt culture growth.