2020 年 26 巻 3 号 p. 445-450
Unheated soymilk (raw soymilk), which was prepared in the laboratory, was heated sequentially at two different temperatures. The proportion of protein particles in the soymilk sample subjected to a low-to-high two-step heating procedure (heating at 70 or 80 °C, then at 100 °C) was almost twice that of a high-to-low two-step heating procedure (heating at 100 °C, then at 70 or 80 °C). The size distribution of oil droplets in the soymilk for two-step heat treatment exhibited a polymodal distribution irrespective of the temperature combinations. However, the low-to-high two-step procedure resulted in an increase in the ratio of aggregated or coalesced oil droplets, in contrast to that for the high-to-low two-step procedure. When using the 7S (β-conglycinin) and 11S (glycinin) fractions separately, each fraction showed increased aggregation after two-step heat treatment, but a 1:1 mixture of the two fractions did not.