原花青素对淀粉理化性质影响及其作用机制研究

Abstract：Starch based food is an important staple food. Proanthocyanidins，a class of condensed tannins that are widely found in plants, have many physiological functions. The coexistence of starch and proanthocyanidins is common in food, people are more and more consciously to add phenolic compounds to starch based products for developing new functional foods. To date, the research of influence between starch and proanthocyanidins is very few and their mechanism is not clear. The project intends to classify different structure proanthocyanidins from proanthocyanidins standard material. Five kinds of starch (rice starch, potato starch, pease starch, high amylase corn starch and waxy corn starch) were selected. Each different structural proanthocyanidins were mixed with five kinds of starch to form a hybrid system, respectively. The properties of the hybrid system will be explored, including gelatinization, retrogradation and rheological properties and so on. At the same time the influencing rule about the hybrid system would be comprehensive investigated by mathematical statistics. Fourier transform infrared spectroscopy, X-ray diffraction spectrum, nuclear magnetic resonance (NMR), atomic force, laser confocal fastidious and molecular modeling were selected to explore the mechanisms of interaction between proanthocyanidins and starch. This study will provide a reasonable and scientific application and guidance for functional proanthocyanidins in starchy food processing.

淀粉基食品是人类重要主食，原花青素是广泛存在植物中的一类聚多酚，具有众多的生理功能。淀粉与原花青素共存常见于食品中，人们也越来越有意识地添加酚类化合物至淀粉基产品中开发新型功能性食品。但是目前关于原花青素对淀粉理化性质的影响研究罕见报道，其作用机制尚不明确。本项目拟采用分级纯化手段制备不同结构原花青素，分别与5种淀粉（大米淀粉、马铃薯淀粉、豌豆淀粉、高直链玉米淀粉、蜡质玉米淀粉）进行二元复配，考察其复合体系的糊化、老化、流变等理化性质，采用偏最小二乘回归等数理统计分析原花青素结构对淀粉性质的影响规律。通过核磁共振、红外、X衍射、扫描电镜、原子力、激光共聚焦等手段，并结合分子模拟软件共同探讨体系作用机制，为具有保健功能的原花青素在淀粉中的应用提供理论依据和指导。

淀粉来源丰富，在实际生产中应用广泛，天然淀粉在加工过程中某些理化性质的改变会影响淀粉基产品的品质，如易老化和结晶、剪切和热稳定性较差、持水力不足等。多酚常作为功能因子，添加进淀粉基产品中以改善淀粉的理化性质，延缓淀粉的消化。此外，食品加工往往涉及食物组织的破坏和细胞的破裂，引起胞内和胞外物质的释放，释放的内源性多酚常与淀粉接触，从而影响食品的品质。原花青素是一种天然植物多酚类物质，具备抗氧化、抗癌、抗菌、降血压、降血脂等多种生物活性，而其活性与聚合度关系密切。目前关于不同聚合度原花青素对淀粉性质的影响研究罕见报道，其作用机制尚不明确。本项目拟采用分级纯化手段制备不同聚合度的原花青素，并与5种淀粉（大米淀粉、马铃薯淀粉、豌豆淀粉、高直链玉米淀粉、蜡质玉米淀粉）进行二元复配，通过RVA、DSC 考察其糊化性质、流变仪考察体系的流变学和凝胶性质；通过RVA、DSC、XRD考察体系的老化性质；通过测定混合体系的X 衍射图谱、红外图谱、扫描电镜等手段表征混合体系的结构；并以不同添加顺序添加原花青素，探讨原花青素对淀粉体外消化性质的影响，归纳原花青素对不同淀粉理化和消化性质的影响规律。以不同直支比淀粉（高直链玉米淀粉、普通玉米淀粉、蜡质玉米淀粉）和原花青素为研究对象，通过核磁共振氢谱、碘结合分析、动态光散射分析等手段，考察淀粉与原花青素相互作用机制，并将其应用于食品的制备中，为具有保健功能的原花青素在淀粉基产品中的扩展应用提供理论依据和指导。