Abstract：
Our previous experiments found that rapeseed protein (RP) has applicability in low-moisture textured proteins. The amount of RP added is limited to <20 %, but the addition of 20 % RP still brings some negative effects. Therefore, in order to improve the quality of 20%RP textured protein, this experiment added different proportions of sodium tripolyphosphate (STPP) to improve the quality of the product, and studied the physical-chemical properties and molecular structure changes of the product to explore the possible modification mechanism. The STPP not only improved the expansion characteristics of extrudates, but also increased the brightness of the extrudates, the rehydration rate. In addition, STPP increased the specific mechanical energy during extrusion, decreased the material mass flow rate. Furthermore, STPP decreased the starch digestibility, increased the content of slow-digesting starch and resistant starch. STPP increased the degree of denaturation of extrudate proteins, the proportion of β-sheets in the secondary structure of proteins, as well as the intermolecular hydrogen bonding interactions. The gelatinization degradation degree of starch molecules also decreased with the addition of STPP. STPP also increased the protein-starch interactions and enhanced the thermal stability of the extrudate. All these indicate that STPP can improve the physical-chemical properties of extrudate.
摘要：
我们先前的实验发现，菜籽蛋白（RP）适用于低水分纹理蛋白。RP的添加量限制在<20%，但20%RP的添加仍然带来一些负面影响。因此,为了提高20%RP蛋白的质量，为了提高产品质量,并对产物的理化性质和分子结构变化进行了研究,探讨了可能的改性机理。STPP不仅改善了挤出物的膨胀特性，而且还增加了挤出物的亮度，补液率。此外,STPP在挤出过程中增加了比机械能，降低了材料质量流量。此外，STPP降低了淀粉的消化率，增加了慢消化淀粉和抗性淀粉的含量。STPP增加了挤出物蛋白质的变性程度，蛋白质二级结构中β-折叠的比例，以及分子间氢键相互作用。淀粉分子的糊化降解程度也随着STPP的加入而降低。STPP还增加了蛋白质-淀粉相互作用并增强了挤出物的热稳定性。所有这些表明STPP可以改善挤出物的物理化学性能。
