Effect of amino acids, especially cysteine, on viscosity increase of evaporated soymilk

Abstract

Commercial soymilk containing the amino acids cysteine, methionine, glycine, or serine as an additive was evaporated under reduced pressure, and the viscosity of the concentrated soymilk was measured. Only cysteine suppressed the increase in viscosity, and then only slightly, during evaporation. When soymilk with cysteine was evaporated, protein particle formation was suppressed, but oil body aggregation was not affected. Cysteine reduced the increase in viscosity by preventing protein aggregation through the reduction of disulfide bonds.