高水分植物组织蛋白纤维断裂强度变化机理研究

    Study on the mechanism of changes in fracture strength of high moisture plant textured protein fibers

    • 摘要: 为探究高水分植物组织蛋白(HMTVP)纤维断裂强度变化的机理,通过双螺杆挤压机采用不同淀粉添加量和螺杆转速制备样品,并对其微观结构、化学键、分子间作用力、蛋白质二级结构进行分析,确定影响其纤维断裂强度的关键因素。结果表明:随着淀粉添加量增加和螺杆转速提高,HMTVP纤维的断裂强度均呈现先减小后上升的趋势,其中,淀粉添加量为7.5%时断裂强度最小(0.70 N),螺杆转速为280 r/min时最小值为0.73 N;游离巯基和二硫键含量的变化与纤维断裂强度密切相关;随着螺杆转速提高与淀粉含量增加,HMTVP的β-折叠占比总体增加,而β-转角占比总体降低,表明蛋白质分子结构从无序向有序转变;通过Logistic函数拟合,建立了分子间作用力或化学键与HMTVP断裂强度之间的关系模型。研究结果为精准调控淀粉添加量与螺杆转速的工艺提供了理论支撑,为开发具有类肉纤维强度的HMTVP制品提供了理论依据。

       

      Abstract: In order to investigate the mechanism of changes in the fiber breaking strength of high-moisture textured vegetable protein(HMTVP), HMTVP was prepared in this study via a twin-screw extruder with different starch addition amounts and screw rotational speeds. The key factors affecting the fiber breaking strength were revealed by analyzing the changes in the microstructure, chemical bonding, intermolecular forces, and the secondary structure of proteins in HMTVP. The results showed that the fiber breaking strength of HMTVP showed a tendency of decreasing and then increasing with the increase of starch addition and screw speed, with minimum values of 0.70 N(at 7.5%) and 0.73 N(at 280 r·min-1), respectively. The changes in free sulfhydryl and disulfide bond contents were closely related to the fiber breaking strength. With the increase of screw speed and starch content, the β-sheet content in HMTVP exhitited an overall increased, while β turn content decreased, indicating a transition from a disordered to an ordered protein molecular structure. The relationship model between intermolecular forces or chemical bonds and the fiber breaking strength of HMTVP was established by logistic function fitting. It provides theoretical support for precisely regulating the process parameters of starch addition amount and screw rotational speed and offers a theoretical basis for the development of HMTVP products with meat-like fiber strength.

       

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