关键词: 大豆分离蛋白(SPI), 贮藏, 蛋白氧化, 溶解性, 乳化性, 凝胶强度

Abstract:

The effect of natural antioxidants (β-carotene and tocopherol) on the content of carbonyls and total sulfhydryl,
as well as solubility, emulsifying properties, and gel properties of soy protein isolate (SPI) during storage for 12 weeks
was studied. The results showed that in native SPI, carbonyl group content increased sharply and gel strength rose at the
end of the storage period, while total sulfhydryl group content fell and both solubility and emulsifying properties decreased
distinctly. Addition of β-carotene to SPI significantly supressed the increase in carbonyl group content after storage for 12
weeks (P ＜ 0.05); meanwhile, when added together, β-carotene and tocopherol significantly inhibited the decrease in total
sulfhydryl group content (P ＜ 0.05). Each antioxidant could block the decrease in solubility and emulsifying properties of
SPI after storage and partially surpress the increase in gel strenth.

Key words: soy protein isolate (SPI), storage, protein oxidation, solubility, emulsifying properties, gel strength