Formulation and processing of a heat stable calcium-fortified soy milk

Calcium-fortified soy milk (200 mg/100g) was formulated by adding to water (85-90 degrees C) full-fat soy flour (10%), sucrose (2.75%) and soy protein isolate (2.25%). Following homogenization, the blend was twice clarified and pasteurized at 65 degrees C/30 min before refrigeration Samples of the soy milk (45 degrees C) were adjusted to pH 8 before adding calcium lactogluconate (1.55%) and varying amounts of sodium hexametaphosphate or potassium citrate. Samples with 1.25% potassium citrate had the best heat stability. For successful calcium fortification, it is recommended to maintain a calcium-to-protein ratio < 38 mg/g and to use an appropriate sequestering agent at a molar ratio of 0.8/mole calcium.