| Eucalyptus was widely planted in China and a large number of eucalyptus leaves were produced each year.There were only few of eucalyptus in C hina used on the extraction of eucalyptus essential oil,the rest are not used.The preliminary research of this team shows that eucalyptus leaves extract has good antioxidant activity,which proves that antioxidant activity is mainly polyphenols.Through the experiments of laying hens and pigs,it was found that eucalyptus polyphenols had improved antioxidant and meat quality of animals.In order to study the role of eucalyptus polyphenols in animals,the effects and mechanism of eucalyptus polyphenols on the antioxidant and meat quality of beard chickens were studied on the basis of predecessors.The main contents and results of this paper are as follows:(1)Eucalyptus polyphenols is made by the lesves of “guanglin nine”eucalyptus from Zhan Jiang and the process is firstly smashing,extracting by continuous phase transition n-butanein low-temperature environment,concentrating and spry-drying.The content of polyphenols in extract is 31.70%±1.64% and the Germin D(0.63%),Oe B(10.46%),PGG(1.21%)and British oak ellagic element(0.72%),and other components are to achieve quality standards.(2)Eucalyptus polyphenols have influence on antioxidant status of beard chicken in serum and muscle.Compared with control group and positive control group,GSH-Px,SOD,T-AOC and MDA of chickens' serum in 0.6g/kg,0.9g/kg,1.2g/kg groups had no obvious differences(p>0.05).The activity of GSH-Px in the muscle of 0.6,0.9 and 1.2 g/kg Eucalyptus polyphenols was significantly higher than that of the control group(p <0.05),and increased by 4.59%,44.50%,24.65%;0.9g/kg of Eucalyptus polyphenols group was significantly higher than that o f the positive control group(p<0.05),and increased by 66.52%.Compared with the control group and the positive control group,the cotent of MDA in muscle of 0.9g / kg eucalyptus polyphenols group was obviously decreased by 25.40% and 24.29%(p<0.05).Compared with the control group,the activities of GSH-Px and MDA in leg muscle were significantly changed(p<0.05),and the activity of GSH-PX in 0.9and 1.2g/kg eucalyptus polyphenols group was evidently increased by 45.75%,58.72% and 0.9g/kg eucalyptus polyphenols were significantly decreased by 31.30%.Eucalyptus polyphenols could significantly increase the activity of glutathione peroxidase(GSH-Px)in the muscle of beard chickens,and significantly reduce the content of malondialdehyde(MDA)so as to improve the antioxidant capacity.(3)Effect of eucalyptus polyphenols on quality of beard chicken.Eucalyptus polyphenols had no significant effect on the growth performance,the average daily gain and the average daily feed intake in beard chicken(p> 0.05).The exper imental group also had no obviously effects on drip loss,content of collagen,p H(p>0.05).As to meat color,There were no significant changes in L *(brightness)and b *(yellowness)of the breast and leg muscle between the groups(p> 0.05).In addition,a* of 0.6 g/kg eucalyptus polyphenols showed an evidently improvement than that of the control group(p<0.05)and increased by 23.40%.Compared with the co ntrol group,the meats in thigh muscle from 0.6g/kg,0.9g/kg,1.2g/kg groups were all significantly higher in a* value than that from control group(p<0.05)and it was significantly increased by 24.52%,20.60% and 23.07%.Compared with the positive control group,1.2 g/kg eucalyptus polyphenols significantly increased the proportion of oxygenated myoglobin(p<0.05)in the muscle of the pectoral muscle,which was 21.62% higher than that of the positive control group.The content of myoglobin in 0.9g/kg eucalyptus polyphenols group was significantly higher than that in the control group in thigh muscle which enhanced by 25.10%(p<0.05).As to nutrition of muscle and composition of fatty acid,there was no significant effect on the muscle moisture content,protein content and ash content(p> 0.05).0.9g/ kg eucalyptus polyphenols had a significant effect on IMF in breast and thigh muscle of the beard(p<0.05),and the ratio was respectively increased by 34.50% and 30.33%.The fatty acid composition of breast muscle of Eucalyptus polyphenols had no significant change(p> 0.05),and 0.6g/kg eucalyptus polyphenols of oleic acid was 19.07% higher than that of control group(p<0.05).the relative content of linolenic acid in 0.9g/kg Eucalyptus polyphenols group was evidently higher than that in control group and positive group(p<0.05)whichrespectively increased by 32.63% and 37.42%.Compared with the positive control group,the content of saturated fatty acids in muscle of eucalyptus polyphenols group was significantly decreased,the unsaturated fatty acids increased significantly(p <0.05),and the unsaturated fatty acids increased by 11.95%.In terms of flavor component,the content of guanine acid in 0.9g/kg eucalyptus polyphenols group was significantly higher than that in the control group(p<0.05)and the ratio was enhanced by 25.93%.The content of breast glycine in 0.6g/kg eucalyptus polyphenols group significantly higher than the control group and positive control group which were increased by 8.81%(p<0.05).Compared with the control group,the content of pectoral muscle was significantly increased by 13.24% and 13.58%(p<0.05)in 0.6g/kg eucalyptus polyphenols and 0.9g/kg eucalyptus polyphenols;Content of phenylalanine in the muscle of the 1.2g/kg eucalyptus polyphenols was significantly increased by 8.50%(p<0.05).The histidine of the muscle between 0.9g/kg eucalyptus polyphenols and “0.9g/kg eucalyptus polyphenols+ positive control group” was significantly higher than that of the control group,which was increased by 13.85%(p<0.05);Eucalyptus polyphenols can improve a* value,muscle oxygenated myoglobin ratio and myoglobin content significantly;enhance content of IMF and perfectcomposition of fatty acid.At the same time,eucalyptus polyphenols was considered to improve muscle Guanosine,glycine,histidine and phenylalanine,so as to enhance the quality of meat quality.(4)Screening and annotation of differentially expressed genes in muscle of eucalyptus polyphenols by i TRAQ and RN A-seq Techniques.The A0A0A0MQ61,GST,APOA4 genes,and superoxide dismutase and peroxidase of eucalyptus polyphenols were significantly up-regulated and could quickly remove the free radicals produced by lipid metabolism and enhance the antioxidant properties of the body.In addition,the expression of glutathione transferase,glutathione hydrolase and ?-glutamyl transferase gene which belong to glutathione metabolism pathway increased significantly,and the expression of glutathione was enhanced in the pathway which significantly improved the antioxidant capacity of the cells related with the imprvment of GSH-Px activity.a* of muscle and the content of myoglobin were significantly increased,which was closely related to the heme binding,hemoglobin complex and hemoglobin binding founded in this passway.At the same time,the color-related gene Mb was significantly up-regulated which lead to the content of hemoglobin and myoglobin in the muscle,causing a change in flesh color.Long chain fatty acid transport,fatty acid degradation and other metabolic pathways caused by changes in muscle fatty acid composition changes;and amino acid-related metabolic pathways,including arginine and proline metabolism. |
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