Calcium coagulation properties of hydrothermally processed soymilk

The effects of hydrothermal cooking (HTC), a steam‐injection process otherwise known as jet cooking, on the calcium salt coagulation properties of soymilk were determined. Full‐fat soymilk was processed at five different conditions (traditional kettle cooking at 100°C for 5 min, HTC at 100°C for 20 s, HTC at 134°C for 26 s, HTC at 154°C for 31 s, and HTC at 162°C for 35 s) and coagulated at four calcium chloride concentrations (0.05, 0.10, 0.20, and 0.30%). Tofu yields and recoveries of dry matter and protein in the coagulated curd followed similar trends with increasing calcium chloride concentration, namely, an initial increase rising to a peak followed by a decrease. HTC‐processed soymilks, especially those processed at high temperature (162°C), gave lower tofu yields and lower recoveries of dry matter and protein in tofu. HTC‐processed soymilks, especially those processed at 134°C or higher, resulted in very soft, fragile, and adhesive tofu. The high calcium salt tolerance of HTC‐processed soymilk might be used to improve dispersion stability of calcium‐fortified soy‐based dairy analogs.