膳食纤维和阿魏酸对面团醒发过程中麦谷蛋白大聚体聚集态的影响及其分子间相互作用

The Effect of Dietary Fiber and Ferulic Acid on the Aggregation of Glutenin Macropolymerand Intermolecular Interactions during Dough Resting

本文通过测定蛋白质粒径分布、分子质量分布及亚基变化探究膳食纤维(DF)与阿魏酸(FA)在面团醒发过程中对麦谷蛋白大聚体(GMP)聚集态的影响;同时通过荧光光谱、紫外光谱及游离氨基含量的测定探究膳食纤维与阿魏酸与GMP蛋白质分子之间的相互作用。结果表明,在面团醒发过程中GMP由小粒径(<11μm)聚集为大粒径(>50μm)。FA会使较高分子质量范围的谷蛋白亚基发生解聚,DF+FA可以降低这种解聚作用对GMP分子质量分布的影响,将亚基比值维持在0.25。荧光光谱与紫外光谱表明,FA使含有色氨酸与酪氨酸残基的蛋白结构段暴露在极性更强的水相环境中。DF与FA与GMP之间可能通过共价交联作用使蛋白质分子中游离氨基含量分别显著下降(P<0.05)22.48%与17.38%(面团醒发90min时),导致蛋白质结构发生变化。结论 :DF与FA的添加会对GMP蛋白质的分子聚集产生影响,并且会与GMP蛋白质之间产生分子间相互作用,使GMP的结构产生变化。

The effects of dietary fiber(DF)and ferulic acid(FA)on the aggregation of Glutenin macropolymer(GMP)were studied by measuring the protein particle size distribution,molecular weight distribution and subunit changes during dough resting;At the same time,the interactions between dietary fiber or/and ferulic acid and GMP protein moleculeswere explored by fluorescence spectrum,ultraviolet spectrum and free amino content.The results showed that during the dough resting process,GMP aggregated from small particle size(<11μm)into large particle sizes(>50μm).FA depolymerized the glutenin subunits in the high molecular weight range.DF+FA reduced the impact of this depolymerization on the GMP molecular weight distribution and maintain the subunit ratio at 0.25.Fluorescence spectra and ultraviolet spectra showed that FA exposed the protein structure segments containing tryptophan and tyrosine residues to a more polar aqueous environment.The content of free amino groups in protein molecules might be significantly reduced(P<0.05)by 22.48%and 17.38%respectively(when the dough resting for 90 min)through covalent cross-linking between DF/FA and GMP,resulting in changes in protein structure.Conclusion:The addition of DF and FA had an impact on the molecular aggregation of GMP proteins,and generated intermolecular interactions with GMP proteins,resulting in changes in the structure of GMP.