Effect of Storage Time on Solubility and Color of Spray-Dried Soymilk‡

Soymilk was spray dried under various combinations of inlet air temperature and atomizer speed. The insolubility index and the tristimulus color parameters (L, a, b) of the dried soymilk were monitored over a 59-week storage time period. The soymilk insolubility exhibited erratic trends over time. Yellowness (b) and lightness (L) of the dried soymilk correlated well with dryer atomizer speed. Yellowness data, however, showed no significant difference among treatments, even when variations over time where considered. Lightness data, on the other hand, was found to be a function of storage time and atomizer speed and could be predicted to within a ± 1.0% error.