CaCl_2对纤维核诱导乳清浓缩蛋白聚合能力的影响

Effect of CaCl_2 on Aggregates of Whey Protein Concentrate with Adding Fibril Nuclei

研究了CaCl_2对两种核诱导乳清浓缩蛋白(WPC)在聚合方面的影响。通过向WPC自发、均相核诱导WPC、二次核诱导WPC形成纤维过程中添加CaCl_2,可提高纤维体系的硬度、黏度以及聚合率,并且对核诱导形成的纤维聚合物影响较大。添加CaCl_2后,核诱导的硬度增加量是WPC自发硬度增加量的1.661倍(均相核诱导)和1.821倍(二次核诱导),黏度增加量的对应值为2.261倍(均相核诱导)与2.479倍(二次核诱导)。添加CaCl_2使纤维的形态发生变化,成弯曲聚集体。对于纤维形成的两种路径自发与核诱导,CaCl_2的影响程度不同,与乳清浓缩蛋白自发纤维聚合能力相比,CaCl_2对核诱导乳清浓缩蛋白聚合能力的提升幅度更大。

Whey protein concentrate(WPC)fibril was made at pH value of 2.0 and 90℃.The investigation focused on the impact of adding CaCl 2 on the aggregation of WPC spontaneous,homogeneous nuclei induced WPC and secondary nuclei induced WPC.As adding CaCl 2,the properties of the hardness,viscosity and amount of WPC fibril aggregates with formation spontaneous or induced homogeneous/secondary nuclei were all increased,especially for two nuclei induced whey concentrate proteins.Adding CaCl 2,the hardness was increased by 1.661(homogeneous nuclei induced WPC)and 1.821(secondary nuclei induced WPC)times than that of whey protein concentrate spontaneous,and the viscosity was increased by 2.261(homogeneous nuclei induced WPC)and 2.479(secondary nuclei induced WPC)times.The micro morphology using TEM of WPC aggregates was changed from long and semi-flexible fibrils into curly and cluster polymers when mixed CaCl 2.And the fluorescence intensity was all decreased by adding CaCl 2.It was speculated that because the Th T dye was unable to fully bind with the assembled fibrils.For the two ways of forming fibrils:spontaneous or nuclei induced WPC,there were different results that the aggregation ability of nuclei-induced WPC was even greater than that of spontaneous WPC fibril formation as adding CaCl 2.