不同极性植物多酚对鸡肉非酶抗氧化机制及品质影响的研究

Enzymatic antioxidant mechanisms and effects on meat quality of plant polyphenols have been proved in previous studies; however, non-enzymatic antioxidant mechanisms of which are still not elucidated. Firstly, the polarity (hydrophilic/lipophilic property) will be characterized, and three kinds of typical plant polyphenols with different polarities will be selected. Also, the white feather chicken models for studying the effects of antioxidants supplementation on oxidative status will be set up; to make clear the antioxidant effects of plant polyphenols with different polarities, the near-infrared fluorescence imaging technology is adopted to track their content and deposition in the chicken meat dynamically, their structures and metabolites are identified using LC-MS, and the content of vitamin E (VE), GSH/GSSG and total antioxidant capacity in chicken meat are determined. Based on further correlation analysis between the antioxidant capacity of plant polyphenols with different polarities in chicken meat and quality properties of chicken meat, non-enzymatic antioxidant mechanisms of plant polyphenols in chicken meat will be elucidated, which will provide theoretical foundation for understanding plant polyphenols and utilizing the resources effectively to enhance antioxidant ability of meat and meat products and provide technological support for storage and preservation of land animal food.. The highlight of this research is to adopt near-infrared fluorescence imaging technology to monitor the content changes, deposition location and destination of plant polyphenols with different polarities in the chicken meat in real-time and dynamically, so that the relationship between the different polarities of plant polyphenols and their non-enzymatic antioxidant capacity in chicken meat will be clarified, and the non-enzymatic antioxidant mechanisms will be elucidated.

植物多酚对肉的酶抗氧化效果及机制已经被证实，但其非酶抗氧化机制还未阐述清楚。本项目首先对植物多酚的极性（亲水亲油性）进行表征，筛选出三种具有代表性的不同极性植物多酚；建立白羽肉鸡的氧化模型，采用近红外荧光成像技术动态追踪不同极性植物多酚在鸡肉中的含量变化、蓄积部位，同时采用LC-MS鉴定植物多酚/代谢产物的结构，测定鸡肉中VE含量、GSH/GSSG及总抗氧化能力，明确其对鸡肉的抗氧化作用；通过进一步分析不同极性植物多酚对鸡肉抗氧化能力与鸡肉品质指标的相关性，阐明其对鸡肉的非酶抗氧化机制，为认识并利用植物多酚提高肉及肉制品的抗氧化能力奠定理论基础，为畜产食品贮藏与保鲜提供技术支持。.本项目的特色在于采用近红外荧光成像技术实时监测不同极性植物多酚在鸡肉中的含量变化、蓄积部位、去向等，明确不同极性植物多酚与其在鸡肉中非酶抗氧化能力的相关性，阐明其非酶抗氧化机制。

本项目筛选三种不同极性的植物多酚，研究其对鸡肉的抗氧化作用和鸡肉品质的影响，以期揭示其非酶抗氧化作用机理。将330只14日龄的黄羽肉鸡饲喂一周后、分为11组，每组10只。分别为空白对照组（CON）、氧化油脂组（OC）、氧化油脂+绿原酸组（OCH）、氧化油脂+EGCG组（OEG）、氧化油脂+鼠尾草酸（OCA）、氧化油脂+VE（OVE）、新鲜油脂组（FC）、新鲜油脂+绿原酸组（FCH）、新鲜油脂+EGCG组（FCG）、新鲜油脂+鼠尾草酸（FCA）、新鲜油脂+VE组（FVE）。EGCG水溶性、绿原酸为中极性、鼠尾草酸为脂溶性，三种多酚都有较强的DPPH·清除能力和亚铁离子还原能力，鼠尾草酸和绿原酸、EGCG有较高的生物利用度。三种多酚能显著增加鸡肉和细胞膜中的VE含量、增加鸡肉、肝脏和血清中GSH含量，且鼠尾草酸的效果优于绿原酸和EGCG，鸡肉的提取物也对DPPH·、羟基、超氧阴离子自由基具有较强的清除能力和亚铁离子还原能力，这也是鸡肉在贮藏过程中具有抗氧化能力的原因。植物多酚还可以增强鸡肉贮藏过程中的氧化稳定性，一支了冷藏过程中pH值的增加，抑制高铁肌红蛋白含量的增加，减缓持水性下降等，增加蛋白和脂肪的氧化稳定性，且绿原酸和鼠尾草酸的效果优于EGCG。由此可初步推断，在肉鸡日粮中添加中极性的植物多酚(如绿原酸)，因其良好的通透性和生物利用度，能显著地增加肉的非酶抗氧化物质的含量，对肉的抗氧化能力具有更显著的效果。本研究将为有效利用植物多酚提高畜产品质量提供理论支持。