茶多酚对鸡蛋品质、蛋白凝胶特性、微观结构及蛋清微量元素含量的影响

Effects of Tea Polyphenols on Egg Quality,Protein Gel Properties, Microstructure and Trace Element Contents in Egg Albumen

本试验旨在研究茶多酚对鸡蛋品质、蛋白凝胶特性、微观结构及蛋清微量元素含量的影响。试验选用720只35周龄的罗曼蛋鸡,随机分为5个组,每组6个重复,每个重复24只鸡。对照组饲喂基础饲粮,试验组分别在基础饲粮中添加200、400、600和800 mg/kg茶多酚。预试期2周,正试期8周。结果表明:与对照组相比,添加茶多酚使第8周鸡蛋的蛋白高度和哈夫单位显著增加(P<0.05),蛋白凝胶强度、硬度、胶黏性和咀嚼性显著降低(P<0.05),并且随着茶多酚添加水平提高呈二次曲线变化(P<0.05);添加200、400和600 mg/kg茶多酚使蛋白凝胶呈多孔、疏松和不规则的网状结构;添加茶多酚使蛋清中铜和锰的含量显著降低(P<0.05),但对蛋清中铁和锌的含量没有显著影响(P>0.05)。由此得出,蛋鸡饲粮添加茶多酚可提高鸡蛋蛋白品质,改善蛋白凝胶特性,降低蛋清中铜和锰含量,茶多酚的添加水平为400 mg/kg时效果较为明显。

This test was conducted to evaluate the effects of tea polyphenols (TP) on egg quality,protein gel properties,microstructure and trace element contents in egg albumen. A total of seven hundred and twenty 35-week-old Lohmann laying hens were randomly divided into 5 groups with 6 replicates per group and 24 hens per replicate. Hens in the control group were fed a basal diet,while those in the experimental groups were fed the basal diets supplemented with 200,400,600 and 800 mg/kg TP,respectively. The test lasted for 8 weeks after 2-week adaption. The results showed that,compared with the control group,TP supplementation significantly increased the albumen height and Haugh unit at the 8th week (P<0.05),significantly decreased the protein gel strength,hardness,gumminess and chewiness (P<0.05),and had quadratic effects on the above indices with the TP supplemental level increasing (P<0.05). Adding 200,400 and 600 mg/kg TP made the egg albumen showed porous,loose,irregular and reticular structure. TP supplementation significantly decreased the contents of copper and manganese in egg albumen (P<0.05),while had no significant difference on the contents of zinc and iron in egg albumen (P > 0. 05). It is concluded that TP supplementation can increase egg white quality,improve the protein gel properties,and decrease the contents of copper and manganese in egg albumen. The optimum supplemental level of TP is 400 mg/kg.