胡萝卜汁热杀菌过程中β-胡萝卜素异构化调控其生物利用率的作用机制

It’s a hotspot in food field on how to improve the bioavailability of dietary β-carotene in recent years. Previous researches indicated that the bioavailability of β-carotene was closely related to its cis-trans configuration, while β-carotene was prone to cis-trans isomerization during thermal sterilization. From the perspective of β-carotene structure affecting its bioavailability, this project aims to analyze the influence rule of different thermal sterilization conditions on β-carotene isomerization from carrot juice by HPLC-APCI-MS and HPLC-NMR. After that, the kinetic model of β-carotene isomerization will be constructed, and the Quantum Chemical Software (Gaussian09) will be used to analyze the mechanism of β-carotene isomerization induced by thermal sterilization of carrot juice. Then, the in vitro digestion model, Caco-2 cell model and animal model will be used to evaluate the bioavailability of β-carotene with different configurations, thus to reveal the mechanism of β-carotene isomerization regulate its bioavailability. Finally, the mechanism of β-carotene isomerization induced by thermal sterilization regulating its bioavailability of carrot juice during thermal sterilization will be elucidated. These studies will provide some innovative theoretical basis and technical guidance for the production of carrot juice with high quality, which will have higher bioavailability of β-carotene under the existing β-carotene content.

如何提高膳食β-胡萝卜素生物利用率是近年来食品领域的研究热点。研究发现β-胡萝卜素的生物利用率与其顺反构型密切相关，而热杀菌易导致β-胡萝卜素发生顺反异构。本项目拟从β-胡萝卜素结构影响其生物利用率的角度出发，通过HPLC-APCI-MS、HPLC-NMR分析不同热杀菌条件对胡萝卜汁中β-胡萝卜素异构化的影响规律，构建β-胡萝卜素异构化动力学模型，使用量子化学方法(Gaussian09)分析热杀菌致胡萝卜汁中β-胡萝卜素异构化反应的发生机制；采用体外消化模型、Caco-2细胞模型和动物模型综合评价不同构型β-胡萝卜素生物利用率，揭示胡萝卜汁中β-胡萝卜素异构化调控其生物利用率的作用机制。最终阐明热杀菌致β-胡萝卜素异构化调控胡萝卜汁中β-胡萝卜素生物利用率的作用机制，为在现有β-胡萝卜素含量条件下进一步提高胡萝卜汁中β-胡萝卜素生物利用率，生产高品质胡萝卜汁提供创新性理论依据和技术指导。

胡萝卜汁是一种深受消费者青睐的蔬菜汁产品，如何使胡萝卜汁中的以类胡萝卜素为代表的主要特征营养素更好的被人体吸收是近年来胡萝卜汁领域的研究热点。本项目首先通过文献计量学，对胡萝卜汁研究现状进行了系统可视化分析。进而，阐明了类胡萝卜素的消化吸收相关概念，提出了基于消化阶段而分解的四个生物利用率相关概念，并对应不同的评价模型，分别从摄入价值、消化价值、吸收及代谢价值四个维度对类胡萝卜素进行评价，从消化过程角度科学构建了一套完整、规范的类胡萝卜素消化吸收评价体系，并探讨将该系统扩展应用于其它类似脂溶性营养素生物率评价的潜力。之后，分析了热杀菌及其他关键单元加工操作致胡萝卜汁中β-胡萝卜素异构化反应的发生情况，鲜榨胡萝卜汁和酶解处理胡萝卜汁中只检测出了一种异构体，即9-顺-叶黄素；热烫处理后的胡萝卜汁检测出3种异构体（9-顺-叶黄素，9-顺-α-胡萝卜素，9-顺-β-胡萝卜素），而121℃杀菌处理检测出5种（9-顺-叶黄素，13-顺-叶黄素，9-顺-α-胡萝卜素，9-顺-β-胡萝卜素，15-顺-β-胡萝卜素）。总体而言，热杀菌及其他关键单元加工操作致胡萝卜汁中β-胡萝卜素异构化反应的发生情况，并不如预期所期望的丰富。最后，系统解析了不同冷、热杀菌方式对紫胡萝卜汁综合品质影响，并建立了杀菌紫胡萝卜汁样品品质评价体系模型。对比不同的冷热杀菌技术，HHP是最适合于紫胡萝卜汁的杀菌方式，热杀菌普遍导致紫胡萝卜汁品质的劣变，HTST杀菌后样品品质劣变最严重。项目研究结果将为生产高品质胡萝卜汁提供创新性理论依据和技术指导，具有重要意义。