Influence of thermal treatment on physical, structural characteristics and stability of lactoferrin, EGCG and high methoxylated pectin aggregates
Influence of thermal treatment on physical, structural characteristics and stability of lactoferrin, EGCG and high methoxylated pectin aggregates
复制标题
DOI：
10.1016/j.lwt.2020.109221
复制
发表时间：
2020-05-01
影响因子：
6
通讯作者：
Gao, Yanxiang
中科院分区：
文献类型：
--
作者：
Liu, Jinfang;Yang, Jie;Gao, Yanxiang
胶体体系是一种理想的功能性成分保护和传递载体。其在热处理过程中的稳定性直接影响其保护和输送效率。研究了热处理对乳铁蛋白（LF）、高甲氧基化果胶（HMP）和表没食子儿茶素没食子酸酯（EGCG）二元和三元聚集体的物理、结构特征和热稳定性的影响。随着处理温度的升高，二元和三元配合物的平均粒径显著减小。所有聚集体的绝对xi-电位值高于在相同热条件下处理的天然LF，除了在75和85 ℃下处理的LF-EGCG复合物。荧光光谱和圆二色性分析结果表明，热处理导致聚集体中LF的二级结构发生变化，分子展开和构象转变。但与HMP和EGCG结合后，热处理引起的LF变性效果受到阻碍。此外，不同的组装顺序影响热处理后的三元聚集体的稳定性。因此，二元或三元复合是提高蛋白质热稳定性和复合物整体营养价值的有效策略。
Colloidal system is an ideal protection and delivery vector of functional components. Its stability during thermal processing directly affects its protection and delivery efficiency. In the present study, the effects of heat treatments on physical, structural characteristics and thermal stability of lactoferrin (LF), high methoxylated pectin (HMP) and epigallocatechin-3-gallate (EGCG) binary and ternary aggregates were investigated. The average particle size of binary and ternary complexes decreased significantly with the increase of treatment temperature. The absolute xi-potential value of all the aggregates were higher than native LF treated at the same thermal condition except LF-EGCG complex treated at 75 and 85 degrees C. The outcome of fluorescence spectroscopy and circular dichroism suggested thermal treatment resulted in the change of secondary structure of LF in the aggregates with molecular unfolding and conformation transition. However, its combination with HMP and EGCG hindered the effect of heat treatment caused denaturation of LF. Also, different assembly sequence affected the stability of the ternary aggregates after heat treatment. Therefore, binary or ternary composition is an effective strategy to improve the thermal stability of protein and overall nutritional value of the complex.