马铃薯淀粉糊化度对面团形成的作用机制

The research and development of potato staple food is important for the utilization of potatoes, adjustment of food structure, and improvement of dietary nutrition. As a main ingredient of potato staple food, the degree of potato starch gelatinization has important influence on dough quality formation. Former researches of our team showed that potato granules from different processing technology has a different effect on dough quality and the degree of starch gelatinization in potato granules is of great difference. But the mechanism the degree of gelatinization of potato starch on dough formation is not clear. Firstly, using microscopy and rheometer to verify the particle structures, crystal structures and gel properties of potato starches with different degree of gelatinization. Then, the rheological properties, mechanical properties of composite dough systems with wheat gluten and pre-gelatinized potato starch were studied using dynamic rheological and mechanical thermal analysis. Meanwhile, the changes in molecular distribution, cross-linking of starch and protein and the changes of wheat protein structure in composite dough systems were analyzed by confocal laser scanning microscope and fourier transform infrared spectrometer. All results above will contribute to reveal the molecular interaction mechanism of wheat protein and potato starch with different degree of gelatinization, clarify the molecular basis of potato starch during the process of dough formation, and provide technical support and theoretical basis of potato flour staple products.

马铃薯主食研发对于提高马铃薯利用率、调整食物结构、改善膳食营养具有重要意义。马铃薯淀粉作为马铃薯主食主要成分之一，其糊化度大小对面团品质形成具有重要影响。团队前期研究表明，不同加工工艺生产的马铃薯全粉对面团品质的影响不同，且全粉中淀粉的糊化度不同。但不同糊化度马铃薯淀粉对面团形成的作用机制尚不明确。本项目旨在应用显微观察、流变仪等分析技术，在探明不同糊化度马铃薯淀粉颗粒结构、结晶结构和凝胶特性等基础上，采用动态流变、热机械分析等技术重点研究不同糊化度马铃薯淀粉与小麦蛋白复合面团的流变特性，热机械特性等的变化规律；同时采用激光共聚焦显微、傅立叶变换红外光谱等技术研究复合面团中淀粉与蛋白的分子分布、交联方式及小麦蛋白二级结构的变化。揭示不同糊化度马铃薯淀粉与小麦蛋白的分子互作机制，阐明马铃薯淀粉糊化度影响面团形成的分子基础，为提高马铃薯面制主食产品加工品质提供技术支持和理论依据。

马铃薯主食的研发对于提高马铃薯利用率、调整食物结构、改善膳食营养具有重要意义。马铃薯淀粉作为马铃薯主食的主要成分之一，其糊化度大小对面团品质形成有重要影响。本研究首先制备了糊化度为38.70%-91.13%的马铃薯淀粉样品，利用显微观察、流变仪、傅里叶变换红外光谱仪等探究了不同糊化度马铃薯淀粉颗粒结构、短程有序结构、流变特性及凝胶特性等的差异，建立了马铃薯淀粉糊化度与其理化特性及结构特性的相关性，并利用模拟面团探究了马铃薯淀粉对面筋蛋白网络结构的影响。结果表明糊化度大于38.7%的马铃薯淀粉乳（料液比1:9）可形成具有剪切变稀特性的均一糊状液。马铃薯淀粉初始糊化温度、持水力、黏度与其糊化度呈显著正相关，短程有序性与其糊化度呈显著负相关。糊化度大于38.7%的马铃薯淀粉样品，其完全糊化后的凝胶强度与糊化度呈显著负相关，即部分糊化处理可使马铃薯淀粉在完全糊化后具有较大的凝胶强度。模拟面团的实验结果表明，利用淀粉-蛋白复合体系模拟小麦粉仍有较大局限性，且相较于小麦淀粉，马铃薯淀粉对面筋网络结构破坏作用更强。与马铃薯原淀粉-小麦蛋白复合物相比，部分糊化后的马铃薯淀粉与小麦蛋白复合物的热力学特性更接近与小麦粉。本研究的开展对于指导马铃薯淀粉及全粉的加工工艺，改善马铃薯面制主食产品品质提供了技术支持和理论依据。