小麦籽粒不同部位蛋白质理化特性研究进展

制粉工序不同节点或逐层研磨的小麦粉表示籽粒从外到内不同部位的组分,因其蛋白组分含量和性质各不相同,具有不同的加工特性。明确不同部位蛋白质理化特性,可为制粉、配粉和专用粉生产提供参考。本文综述了小麦蛋白质的分类、蛋白质及其组分在小麦籽粒中的分布,以及不同组分蛋白质的理化性质。小麦籽粒由内向外,蛋白质含量逐渐增大,面筋含量先逐渐增加后降低。越接近外层胚乳或糊粉层,清蛋白、球蛋白、麦醇溶蛋白、麦谷蛋白、十二烷基硫酸钠可溶蛋白、谷蛋白大聚体含量、面筋指数、沉降指数等呈现逐渐增大的趋势,各蛋白质组分的增加幅度不同;面团吸水率和拉伸面积逐渐增加,延伸性逐渐降低;面团形成时间、稳定时间、拉伸阻力等变化规律不明显,总体表现为波动至较大值后降低。

A review on the physicochemical properties of the different fractions of wheat kernel

Wheat kernel is mainly composed of pericarp, aleurone layer, endosperm and germ. Fractions from mill streams or pearling mills indicate different parts of the wheat kernel from the surface to the center. The proteins from various part of wheat kernel have different components and properties, those are one of the reasons for their different processing characteristics. It is necessary to clarify the physicochemical properties of the protein from different part of wheat kernel that can contribute to provide theoretical basis for the flour milling process, flour blending and production of special flours. This study summarized the classification of wheat proteins, the distribution of both proteins and their components in the wheat kernel, and the properties of proteins in order to clear the physicochemical properties of proteins in different parts of the wheat kernel. The results showed that from the wheat kernel center to the surface, the wheat protein content increased gradually and the gluten content initially increased and then decreased. The closer to the outer endosperm or aleurone layer, the albumin, globulin, gliadin, glutenin, SDS soluble protein, the GMP content, the gluten index and the SDS sedimentation value increased gradually. The increasing degrees of various protein components were different. The farinograph water absorption and the extensograph energy increased, but the extensograph extensibility decreased. The changes of the dough development time, the peak time and the extensograph resistance were not obvious, and overall, they fluctuated to a larger value and then decreased.