转谷氨酰胺酶对大豆分离蛋白酶解物的吸油性与保水性的改善作用

通过木瓜蛋白酶酶解大豆分离蛋白(Soy protein isolate,SPI)获得酶解物,然后利用转谷氨酰胺酶(Transglutaminase,TGase)对酶解物进行交联作用,以吸油性和保水性为指标,对交联条件进行响应曲面优化,并对改性前后粒径、Zeta电位、自由氨基含量与吸油性、保水性之间相关关系进行探究。结果表明,TGase添加量21.2 U/g、pH7.1、交联温度53.0 ℃、交联时间1.2 h时,酶解物经TGase交联后的吸油性最佳,为5.41 g/g,较TGase改性前的SPI酶解物(3.98 g/g)提高35.93%,较SPI(3.73 g/g)提高45.04%。在TGase添加量20 U/g、pH7.0、交联温度35 ℃、交联时间1.0 h时,酶解物经TGase交联后的保水性得以较好改善,为17.28 g/g,较TGase改性前的SPI酶解物(14.82 g/g)提高16.60%,较SPI(14.52 g/g)提高19.01%。粒径大小与保水性之间存在显著负相关,Zeta电位绝对值大小与吸油性存在显著正相关,与保水性存在负相关,自由氨基含量与吸油性之间存在显著负相关,相关系数分别为-0.865、0.878、-0.531、-0.595。

Improvement Effect of Transglutaminase on Oil Absorption and Water Retention of Soybean Proteinase Isolates

Soy protein isolate(SPI)was digested with papain to obtain the enzymatic hydrolysates.Transglutaminase(TGase)was used to crosslink the enzymatic hydrolysates,and oil absorption and water retention were used as indicators to optimize the crosslinking conditions by the response surface optimization.The correlation between particle size,zeta potential,free amino content and oil absorption,water retention before and after modification was investigated.The results showed that,when the TGase addition amount was 21.2 U/g,pH value was 7.1,crosslinking temperature was 53.0℃and crosslinking time was 1.2 h,the optimal oil absorption of enzymatic hydrolysates after TGase crosslinking was 5.41 g/g.Compared with the SPI hydrolysates before TGase modification(3.98 g/g),it was 35.93%higher.Compared with SPI(3.73 g/g),the increase was 45.04%.Under the conditions of enzyme addition amount of 20 U/g,pH value of 7.0,crosslinking temperature of 35℃and crosslinking time of 1.0 h,the water retention of the enzymatic hydrolysates after TGase crosslinking was improved to 17.28 g/g.Compared with the SPI hydrolysates before TGase modification(14.82 g/g),it was 16.60%higher.And compared with SPI(14.42 g/g),the increase was 19.01%.There was a significant negative correlation between particle size and water retention.The absolute value of zeta potential had a significant positive correlation with oil absorption and a negative correlation with water retention.And the free amino content had a significant negative correlation with oil absorption.The correlation coefficients were-0.865,0.878,-0.531 and-0.595,respectively.