谷朊抗冻多肽对面团冷冻保护作用研究

Cryoprotective Effect of Gluten Antifreeze Polypeptide on Dough

采用旋转流动仪、SDS-PAGE凝胶电泳和原位拉曼光谱等手段探究谷朊抗冻多肽对面团流变特性、蛋白分子质量分布和分子结构的影响规律。结果表明,经过冷冻(冻融和冻藏)处理后,与对照相比,加入谷朊抗冻多肽的面团黏弹性有所下降,谷朊抗冻多肽可以抑制冷冻过程中GMP的解聚。谷朊抗冻多肽的添加有效维持了面筋蛋白的二级结构和分子排列的有序性,与对照相比,在经过反复冻融和恒温冻藏处理后,α-螺旋结构的质量分数分别提高了3.1%、2.5%,二硫键g-g-g构型质量分数分别提高了8.8%、9.8%,同时使得氨基酸侧链中I 850/I 830值下降、I 760值提高。当谷朊抗冻多肽的质量分数为0.5%时最有效地抑制了冷冻过程中冰晶生长对面筋蛋白网络结构的破坏,谷朊抗冻多肽保护了面筋网络结构的完整性,维持了面筋蛋白在面团中的骨架作用。

In this paper,the effects of gluten antifreeze peptides on dough rheological properties,protein molecular mass distribution and protein molecular structure were investigated by means of rotational flowmeter,SDS-PAGE gel electrophoresis and in situ Raman spectroscopy.The results indicated that after freeze-thawing and frozen storage,the viscoelasticity of the dough added with gluten antifreeze polypeptide decreased compared with the control,gluten antifreeze polypeptide could inhibit the depolymerization of GMP during the freezing process.The addition of gluten antifreeze polypeptide effectively maintained the secondary structure of gluten protein and the order of molecular arrangement.Compared with the control,after repeated freezing and thawing and constant temperature freezing,the relative content ofα-helix increased by 3.1%and 2.5%,and the content of g-g-g configuration of disulfide bond increased by 8.8%and 9.8%,respectively.At the same time,the I 850/I 830 value of the amino acid side chain in the gluten protein was decreased,and the I 760 value was increased.When the addition amount of gluten antifreeze polypeptide was 0.5%,the damage to the gluten protein network structure caused by the growth of ice crystals during the freezing process was most effectively inhibited.The addition of gluten antifreeze polypeptide protects the integrity of the gluten network structure and maintains the skeleton function of gluten protein in dough.