超滤压力对膨化玉米蛋白粉酶解产物性质的影响

采用Alcalase和Protamex蛋白酶对膨化后的玉米蛋白粉进行分步水解,将得到的水解液于室温条件下进行超滤。研究了超滤压力对不同分子量分布的产物性质的影响。结果表明,超滤压力对产物的体积得率、蛋白得率、起泡性及泡沫稳定性和抗氧化活性影响较大,而对黏度、乳化性及乳化稳定性的影响不大。超滤压力在0.08MPa时,各超滤分级产物的功能特性和抗氧化活性都较好。在该压力下,分子量≤6kDa的产物体积得率最大;分子量在6～10kDa和分子量≥20kDa的产物蛋白得率均在18%左右;随着分子量的增大,产物的黏度都在1.2～1.9mPa·s之间,起泡性在148%～207%之间,但是泡沫稳定性较差;分子量≥20kDa的产物乳化性最高,达到45.71,超滤分级产物的乳化稳定性无明显变化;分子量≤6kDa的产物抗氧化活性最高。

Effects of Conditions of Ultra Filters on Characters of Enzymatic Modified CGM

In this paper,the proteins of corn gluten meal(CGM)were hydrolyzed by proteinase Alcalase and Protamex in order.Under room temperature,the hydrolysates were treated by ultrafiltration membranes of 20 kDa,10 kDa and 6 kDa cut-offs,and four fractions of ≥20 kDa,20～10 kDa,6～10 kDa and ≤6 kDa were obtained:The effect of different ultrafiltration pressure on functional properties and anti-oxidative activity of different molecular weight hydrolysates were studied.The results indicated that the yields of volumes and the proteins,the foam properties,and anti-oxidative activity of the hydrolysates were effected obviously by the pressure,while the viscosity and the emulsibility were not effected obviously.Under the pressure of 0.08 MPa,the functional properties and anti-oxidative activity of all of four fractions were better.The volume yield of the fraction of molecular weight ≤6 kDa was the highest.The protein yields of molecular weight of 6～10 kDa and ≥20 kDa were about 18%.The values of viscosity of all fractions were between 1.2～1.9 mPa·s,and the values of foam ability were between 148% and 207%,but the values of foam stability were lower.The emulsibility of the fraction of ≥20 kDa was the highest.The emulsion stability did not change obviously.The anti-oxidative activity of the fraction of ≤6 kDa was the highest.