不同虫态米象侵害对小麦蛋白理化和结构特性的影响

为探索不同虫态米象侵害对小麦蛋白品质的影响,该研究以米象侵害后的小麦为研究对象,对米象不同虫态（卵期、幼虫期、蛹期、成虫期）侵害后的小麦粗蛋白、尿酸、蛋白组分、湿面筋、面筋吸水量、乳酸溶剂保持力（solvent retention capacity,SRC）、蔗糖SRC、巯基（-SH）、二硫键（-S-S-）、蛋白质二级结构、面筋蛋白显微结构以及制成全麦面条的色泽和质构特性等进行测定与分析。结果表明,米象的侵害会使小麦蛋白的理化特性和形态结构变差。随着米象的生长发育,小麦籽粒中粗蛋白的含量显著上升,湿面筋、面筋吸水量,乳酸SRC、蔗糖SRC,- SH和- SS -的含量下降,小麦蛋白组分和二级结构比例发生显著变化(P<0.05),小麦的食用品质和营养价值降低。面筋蛋白显微结构显示：随着米象在小麦籽粒内部生长发育,面筋表面粗糙程度加重,断裂面和毛刺增多,到达成虫期后,部分面筋结构已经严重断裂,无法识别。制成全麦面条后,面条的色泽加深,L*值、蒸煮损失率增大,a*值、b*值、硬度、黏附性、弹性、内聚性、咀嚼性和回复性降低。该试验结果进一步阐明了米象侵害后小麦品质的劣变机制,为小麦贮藏期间及虫蚀小麦的品质改良提供了一定的理论基础。

Effects of rice weevil in different life states on the protein physicochemical and structural properties of wheat

In the process of wheat storage, rice weevil is a kind of extremely harmful moth-eaten pest, which belongs to the hidden pest that eats inside the grain, and in the growth and development process of rice weevil (egg stage, larva stage, pupa stage, adult stage), there are different degrees of damage to wheat until the adult stage is drilled out. In severe cases, wheat grains can be eaten into empty shells, and the excrement is left inside the grains, which seriously damages the protein quality of wheat and affects the quality of flour. In order to explore the effects of rice weevil infection on wheat protein quality at different stages. In this paper, the crude protein, uric acid, protein components, wet gluten, gluten water absorption, lactic acid solvent retention capacity (SRC), sucrose SRC, sulfhydryl (-SH), disulfide bond (-S-S-), protein secondary structure, gluten protein microstructure of the wheat infected by rice weevil and the color and texture characteristics of the corresponding whole wheat noodles were measured and analyzed. The results showed that the growth and development of rice weevil in wheat and the damage of wheat would cause a series of changes in wheat protein, which was manifested in the deterioration of physical and chemical properties and morphological structure. With the growth and development of rice weevil inside the wheat kernels, the content of crude protein in wheat grains increased significantly, the content of wet gluten, gluten water absorption, lactic acid solvent retention SRC, sucrose SRC, -SH and-SS-decreased, The proportion of wheat protein components and secondary structures, which are very important for wheat, also changed significantly (P<0.05), and the edible quality and nutritional value of wheat also decreased. The microstructure of gluten protein showed that with the growth and development of rice weevil in wheat grains, the surface roughness of gluten increased, and the fracture surface and burr increased. After reaching the adult stage, some gluten structures had been seriously broken and could not be identified. After making whole wheat noodles, the color of noodles deepened, L* value and cooking loss rate increased, a* value, b* value, hardness, adhesion, elasticity, cohesiveness, chewiness and resilience decreased. The experimental results further elucidated the deterioration mechanism of wheat damaged by rice weevil, and provided a theoretical basis for the quality improvement of wheat during storage and the insect infected wheat.