以10 mg/L Na2SeO3溶液浸泡的大豆为材料,采用碱提酸沉法制备大豆分离蛋白(soybean protein isolate,SPI),以葡萄糖酸-δ-内酯(GDL)为凝固剂制备大豆蛋白凝胶,系统研究了富硒处理及发芽时长对大豆蛋白凝胶性质的影响。结果发现:发芽48 h内大豆GDL凝胶与SPI凝胶的硬度快速下降,分别由25.25 g和27.73 g降至10.77 g和13.37 g,持水性从61.42%和62.64%分别降至51.55%和55.54%。SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)图谱显示,富硒大豆与对照SPI谱带变化基本一致,其中7S球蛋白的β亚基与11S球蛋白的碱性亚基B较稳定,而7S球蛋白的α'亚基和α亚基与11S球蛋白的酸性亚基A3和A则被内源蛋白酶逐渐降解为相对分子质量较小的组成,从而影响发芽大豆凝胶性质。而富硒处理对发芽大豆蛋白凝胶性质影响较小。

After immersion 6h in 10 mg /L Na2SeO3 solution,soybean was germinated 96 h at optimal conditions.Soybean protein isolate(SPI) was obtained from germinated soybean with alkaline extraction and acid precipitation method.After adding GDL,soy protein gels were analyzed by Texture Analyzer and the impact of Se and the germination time on gel property was investigated.The results showed that the hardness of soybean gel and SPI gel decreased rapidly from 25.25 g to 10.77 g and from 27.73 g to 13.37 g respectively during 48 h germination.Water holding capacity(WHC) of soybean gel and SPI gel decreased from 61.42% to 51.55% and from 62.64% to 55.54% respectively.The changes of SPI during germination were discussed by SDS-PAGE mapping.The results showed that β-7S subunit and B-11 S subunit were relatively stable,while α'-7S,α-7S,A3-11 S and A-11 S subunits were easily hydrolyzed by intra-proteases.At the same germination time,the protein bands of se-enriched soybean were similar with the control group.It showed that enriched selenium treatment had a little effect on gel property of soybean protein during germination.