Wu Qiong, Tian Qisheng, Zhang Dongdong, Zhang Yurong
Engineering Research Center of Grain Storage and Security of Ministry of Education, Henan Provincial Engineering Technology Research Center on Grain Post Harvest, School of Food and Strategic Reserves, Henan University of Technology, Lianhua Road 100, Zhengzhou High-Tech Development Zone, Zhengzhou, 450001, Henan, China.
J Econ Entomol. 2022 Dec 14;115(6):2092-2104. doi: 10.1093/jee/toac168.
Boring pests such as Sitophilus zeamais (S. zeamais) are major threats in grain storage. However, how these pests affect the proteins of stored grains remains largely unknown. Here we aimed to investigate the effect of S. zeamais infestation on wheat protein during postharvest storage. In this study, wheat grain infested by S. zeamais was sampled at egg (4 d), larval (20 d), pupal (35 d), and adult stages (45 d), respectively. The protein's physicochemical and structural properties and the edible quality of whole wheat noodle were analyzed. The results showed that S. zeamais infestation significantly decreased the quality of wheat protein by altering its constitution and structure properties. Especially, compared with the control, the content of wet and dry gluten, gluten index, sodium dodecyl sulfate sedimentation volume, sulfhydryl groups, and disulfide bonds in insect-infested wheat decreased by 19.40, 5.42, 18.40, 8.12, 29.13, and 14.30%, respectively, during the storage period of one life cycle of S. zeamais. Additionally, the proportions of wheat protein fractions (albumin [1.16-fold], globulin [0.96-fold], gliadin [1.16-fold], and glutenin [0.95-fold]) and secondary structures (α-helix [0.91-fold], β-fold [0.96-fold], β-turn [1.06-fold], and random coil [1.05-fold]) of protein changed significantly, and the gluten network structure was broken in S. zeamais-infested wheat. Furthermore, the color of whole wheat noodle became darker, cooking loss rate increased, and textural properties (hardness, adhesiveness, springiness, cohesiveness, chewiness, and resilience) decreased as well. The results in the present study provided new insights for analyzing the quality deterioration mechanism and further quality improvement of boring pests-infested wheat grain.
像玉米象（Sitophilus zeamais）这样的蛀害虫是谷物储存中的主要威胁。然而，这些害虫如何影响储存谷物的蛋白质在很大程度上仍不清楚。在此，我们旨在研究玉米象侵染对小麦收获后储存期间蛋白质的影响。在本研究中，分别在卵期（4天）、幼虫期（20天）、蛹期（35天）和成虫期（45天）对受玉米象侵染的小麦籽粒进行采样。分析了蛋白质的物理化学和结构特性以及全麦面条的食用品质。结果表明，玉米象侵染通过改变其组成和结构特性显著降低了小麦蛋白质的品质。特别是，与对照相比，在玉米象一个生命周期的储存期内，受虫害小麦中的湿面筋和干面筋含量、面筋指数、十二烷基硫酸钠沉淀体积、巯基和二硫键分别下降了19.40%、5.42%、18.40%、8.12%、29.13%和14.30%。此外，小麦蛋白质组分（清蛋白[1.16倍]、球蛋白[0.96倍]、醇溶蛋白[1.16倍]和谷蛋白[0.95倍]）的比例以及蛋白质的二级结构（α-螺旋[0.91倍]、β-折叠[0.96倍]、β-转角[1.06倍]和无规卷曲[1.05倍]）发生了显著变化，并且在受玉米象侵染的小麦中面筋网络结构被破坏。此外，全麦面条的颜色变深，煮损率增加，质地特性（硬度、粘附性、弹性、内聚性、咀嚼性和回复性）也下降。本研究结果为分析蛀害虫侵染小麦籽粒的品质劣化机制和进一步改善品质提供了新的见解。
