热改性豌豆分离蛋白与卡拉胶复合相行为及表征

Heat-treated pea protein isolated/carrageenan complex coacervates:Phase behaviors and characterization

该研究采用ζ-电位法和浊度滴定法评价了卡拉胶(carrageenan, CG)类型(κCG,ιCG,λCG)对热改性豌豆分离蛋白(heat-treated pea protein isolated, HPPI)在不同质量比(0.5∶1~6∶1)和不同pH(7.0~2.0)相行为的影响,并对不同类型复合物进行了表征。结果表明,卡拉胶电荷密度对相变过程有显著影响,HPPI和κCG,ιCG、λCG的临界质量混合比分别是1.5∶1、3∶1、3∶1;3种卡拉胶均能抵抗HPPI的聚集,但是ιCG具有最好的抵抗效果,可归因于其独特的分子构型和硫酸盐数量,HPPI和3种卡拉胶的相图均可以分为3个相区;HPPI和ιCG以静电相互作用和氢键结合形成复合物,相比于单独的HPPI,复合物的疏水性降低,并且呈团簇和聚集态分布。该研究对于更深入了解蛋白质和多糖的相互作用以及对食品系统的设计和稳定性调控具有重要意义。

The application of heat-treated pea protein isolated(HPPI)in food is often limited by aggregation after heating,whereas the formation of complexes with carrageenan can solve this problem.This study evaluated the impact of carrageenan(CG)types(κCG,ιCG,λCG)on the phase behavior of HPPI at different mixing mass ratios(6∶1-0.5∶1)and different pH values(7-2)usingζ-potential and turbidity titration methods,and different types of complexes were characterized.Results indicated that the charge density of carrageenan could significantly affect the phase transition process.The critical mixing mass ratio of HPPI-κCG,ιCG,andλCG was 1.5∶1,3∶1,and 3∶1,respectively.The three kinds of carrageenan could resist HPPI aggregation,butιCG exhibited the best resistance,attributed to its unique molecular configuration and sulfate content.The phase diagrams of HPPI and the three carrageenans could be divided into three phase regions.HPPI andιCG formed a complex through electrostatic interactions and hydrogen bonding.Compared to HPPI alone,the complex exhibited reduced hydrophobicity and was distributed in clusters and aggregates.This study is of significant importance for a deeper understanding of the interactions between proteins and polysaccharides and for the design and stability control of food systems.