淀粉美拉德反应产物的消化特性及构效关系研究

Slowly digestible starch (SDS) is able to generate stable blood glucose level, which is important for human health. In this study, starches from different sources, different category, and different modification were conjugated with amino acids by the Maillard reaction. The rate and extent of digestibility of Maillard starch was measured using the in vitro Englyst assay. Other biochemical and structural properties of Maillard starch were also studied by the DSC, X-ray, FT-IR, AFM, etc., and the structure basis was modeled in a computer matrix. The objective of this research was to study the digestibility characteristic and structure-activity relationship of Maillard starch. Firstly,The influence of different reaction conditions on the digestibility characteristic of Maillard starch were investigated in this paper, and to investigate the relationship between the rate and extent of digestibility and the Maillard condition, and illustrate its changes mechanism. Secondly, the study was carried out to characterize the reaction of Maillard starch with amino acids, in order to reveal the relationship between the biochemical properties and structure basis, and to investigate the influences of structural and biochemical properties on the rate and extent of digestibility. At last, a structural model of Maillard starch was evaluated with experimental values by quantitative structure-activity relationship (QSAR) that analyze the correlation of the branched structure and digestibility characteristic. This processing may give rise to the appearance of new slowly digestible starch and it is applicable as a novel technique for preparing the slowly digestible starch product in food industry.

慢消化淀粉能够产生较为稳定的血糖水平，对人类健康有重要作用。本项目以不同来源、不同类型、不同改性的淀粉和氨基酸为实验材料，采用经典体外消化法，利用差示量热扫描仪、X-射线衍射仪、傅里叶红外光谱和原子力显微镜等先进分析技术，同时结合计算模拟，研究美拉德淀粉的消化特性及构效关系。首先，研究美拉德体系环境对美拉德淀粉消化性质的影响，阐明美拉德淀粉消化速度和抗消化性能与美拉德反应环境因素之间的内在关系及变化规律；其次，通过考察淀粉分子与氨基酸分子之间的相互作用，研究美拉德淀粉分子结构与其理化特性之间的内在联系，阐明美拉德淀粉分子结构和理化性质的变化对消化速度和抗消化性能的影响；最后，对美拉德淀粉进行分子结构表征，在分子水平上构建美拉德淀粉分子结构与抗消化性能之间的定量构效关系（QSAR）模型。从而指导新型慢消化淀粉的发现与"绿色"合成。

本课题以玉米淀粉为原料，采用氨基酸与淀粉共混，通过干热、湿热和高压处理，研究各种处理方式对淀粉与氨基酸共混物的营养特性、糊化特性、粒径分布、形态学性质和结构性质的影响，并推断其作用机理。.干热处理玉米淀粉-氨基酸混合物，快消化淀粉含量和慢消化淀粉含量均增加，抗消化淀粉含量降低。糊化曲线显示，淀粉的糊化温度降低，峰值粘度升高，低谷粘度、最终粘度、回复值和峰值时间均降低。混合物晶形没有发生改变，结晶度降低。热力学参数（To、TP、TC和∆H）降低。粒径分布显示，峰形出现变化，由双峰变成三峰，平均粒径增加。.湿热处理玉米淀粉-氨基酸混合物，快消化淀粉含量和慢消化淀粉含量均增加，抗消化淀粉含量降低。混合物晶形没有发生改变，结晶度降低。热力学参数To、TP、TC升高，∆H降低。偏光显微镜观察，淀粉以及淀粉与氨基酸共混物的双折射强度均有所减弱，部分淀粉颗粒中心的双折射区域变弱，而颗粒边缘的双折射基本不变。.高压处理玉米淀粉-氨基酸混合物，快消化淀粉含量和慢消化淀粉含量均增加，抗消化淀粉含量降低。混合物晶形发生改变，结晶度降低。热力学参数To、TP和TC均升高，焓值略有减小。通过扫描电镜观察发现，淀粉颗粒结构破损，颗粒中心出现大型孔洞。.通过系统研究上述三种制备方法对玉米淀粉-氨基酸混合物慢消化淀粉含量及结构性质的影响，发现湿热处理方法最适宜制备高含量的慢消化淀粉，是一种绿色、环保的新型慢消化淀粉加工方法。. 研究成果：发表论文1篇，SCI收录1篇；申请发明专利3项。