杨梅多酚抑制高温加工食品AGEs形成机理的研究

The content of advanced glycation end products (AGEs) in high-temperature processed foods is much higher than that in the steamed foods made from the same ingredients. The accumulation of AGEs in the body has a negative impact on human, the dietary AGEs (dAGEs) are chronic risky factors which may damage tissue and body. A growing number of scholars began to study the mechanism of the formation of AGEs in foods processing, search for natural inhibitor to reduce AGEs in foods. In the previous study we found that the bayberry polyphenols possess good capacity of inhibiting the formation of the AGEs, but the mechanism is not clear. Based on the simulated high-temperatur processing system consisting of BSA and glucose, the relation between bayberry polyphenols and the content of AGEs in the BSA-Glucose simulated system will be investigated, the content of glyoxal, methylglyoxal will be determined, and the dynamic changes of protein carbonyl concentration, protein thiol concentration, molecular weight, the content of bayberry polyphenols in BSA-Glucose simulated system will be measured, and the structures of carbonyl adducts formed from bayberry polyphenols and methylglyoxal will be identified as well. Based on the experiments the mechanism of bayberry polyphenols inhibit the formation of advanced glycation end products in the high-temperature processed foods will be discussed. The results aim to provide theoretical basis on reducing AGEs in the high-temperature processed foods.

油炸和焙烤等高温加工食品晚期糖基化终末产物（AGEs）的含量远高于相同材质的蒸煮食品。AGEs在体内的积累会对人体产生不良影响，食源性AGEs是造成机体损伤的一个慢性危险因素，越来越多的学者开始关注食品中AGEs的形成机制，并寻求天然抑制剂以降低食品中AGEs。杨梅多酚具备较强的AGEs形成抑制能力，但是其抑制机理尚不清楚。本项目建立牛血清蛋白-葡萄糖（BSA-Glucose）AGEs形成模拟体系，探究在不同高温加热条件下杨梅多酚与模拟体系AGEs形成的时效关系和量效关系；研究BSA-Glucose模拟体系高温加热前后乙二醛（GO）、甲基乙二醛（MGO）等重要中间体的动态变化，模拟体系中蛋白质羰基浓度、巯基浓度、分子量、杨梅多酚含量的变化，以及对杨梅多酚与MGO加合产物的鉴定，探讨杨梅多酚抑制高温加工食品AGEs形成的机理。研究结果旨在为降低高温加工食品中AGEs的含量提供理论依据。

高温加工食品晚期糖基化终末产物（Advanced glycation end products, AGEs）的含量较高。AGEs是美拉德（Maillard）反应的产物之一，主要包括内源性AGEs 和外源性AGEs两大类。外源性AGEs是指人体从外部摄入或来源于食品的AGEs，其中大部分是由膳食带入人体内，称为食源性AGEs（Dietary AGEs，dAGEs）。dAGEs是体内AGEs的主要来源之一，有研究指出人体在摄入富含AGEs的食品后，大约有10%的dAGEs 以小分子颗粒的形式与短肽和氨基酸一同进入血液循环，仅三分之一通过肾脏排出体外，其余三分之二留在体内参与形成内源性AGEs，人体组织和循环系统中积累过多的AGEs，易引起糖尿病、动脉粥样硬化等疾病的发生。由此可见，食源性AGEs是造成机体损伤的一个慢性危险因素，越来越多的学者开始关注食品中AGEs的形成机制，并寻求天然抑制剂以降低食品中AGEs。.较多研究表明酚型植物提取物能够很好地抑制AGEs的形成。杨梅多酚含有丰富的花色苷和多种酚类化合物，具备较强的AGEs形成抑制能力，但是其抑制机理尚不清楚。本项目建立牛血清蛋白-葡萄糖（BSA-Glucose）AGEs形成模拟体系，以氨基胍（Amino guanidine, AG）作为阳性对照，明确了杨梅多酚（Bayberry Polyphenol, BP）与牛血清蛋白-葡萄糖（BSA-Glucose）模拟体系在70 ℃孵化过程中AGEs形成的时效关系和量效关系，其中杨梅多酚浓度越高抑制作用越强。基于模拟体系中重要中间体甲基乙二醛（methylglyoxal, MGO）的变化、蛋白质分子量、羰基和巯基含量、糖基化与非糖基化牛血清蛋白的比例（Gly-BSA/Ori-BSA）等变化初步明确杨梅多酚抑制AGEs形成的途径，即杨梅多酚通过清除了模拟体系中的·OH、MGO中间体，以及保护蛋白质巯基、抑制蛋白羰基化、减少蛋白质交联来阻断AGEs的形成。研究结果为降低高温加工食品中的AGEs建立了主动防御措施，为减少食品潜在的危害物提供了新的途径。