【作者】 李伟；

【导师】 曹庸；

【作者基本信息】 华南农业大学 ， 食品科学， 2017， 硕士

【摘要】 桉树在我国种植面积广阔,每年产生大量桉叶,桉叶在我国除部分用于提取桉叶精油外,其余都未加利用。本团队前期研究表明桉叶提取物具有很好的抗氧化活性,证明起抗氧化作用主要是多酚类物质。通过蛋鸡和肉猪实验,发现桉叶多酚具有提高机体抗氧化和改善肉质的性能。为了深入研究桉叶多酚在动物体内的作用,本文在前人基础上继续研究桉叶多酚对胡须鸡抗氧化性能和肉质品质的影响及机理研究。本文的主要研究内容和结果如下所示:(1)实验原料选用湛江“广林九号”桉树叶,经粉碎、低温连续相变提取、浓缩喷雾干燥等方法,制得桉叶多酚。本次试验桉叶多酚中多酚含量31.70%±1.64%,其中5-甲氧基糠醛(0.63%)英国栎鞣花素(0.72%)、月见草素B(10.46%)以及1,2,3,4,6-五没食子酰基葡萄糖(1.21%)等成分达到质量标准。(2)桉叶多酚对胡须鸡血清和肌肉抗氧化性能的影响。桉叶多酚对胡须鸡血清抗氧化影响如下:各组血清GSH-Px、T-SOD、T-AOC、MDA含量相差不大(p>0.05)。在胸肌肌肉中,0.6、0.9、1.2g/kg桉叶多酚组胸肌肌肉GSH-Px活力显著高于对照组(p<0.05),分别提高了4.59%、44.50%、24.65%;0.9g/kg桉叶多酚组GSH-Px活力显著高于阳性对照组(p<0.05),提高了66.52%。相对于对照组和阳性对照组,0.9g/kg桉叶多酚组胸肌肌肉MDA显著降低了25.40%、24.29%(p<0.05)。相对于对照组,腿肌肌肉中GSH-Px活力和MDA含量均有显著变化(p<0.05),其中0.9、1.2g/kg桉叶多酚组腿肌肌肉GSH-Px活力显著提升了45.75%、58.72%,0.9g/kg桉叶多酚组腿肌肌肉MDA含量显著降低了31.30%;桉叶多酚可以显著提高胡须鸡肌肉中谷胱甘肽过氧化物酶(GSH-Px)活力,同时显著降低丙二醛值(MDA)含量,改善机体抗氧化能力。(3)桉叶多酚对胡须鸡肉质品质的影响。桉叶多酚对胡须鸡料肉比、平均日增重以及平均日采食量等生长性能指标无显著影响(p>0.05);桉叶多酚各实验组对肌肉滴水损失、胶原蛋白、p H无显著影响(p>0.05)。在肉色方面,桉叶多酚各实验组胡须鸡胸肌和腿肌肉色中L*(亮度)、b*(黄度)无明显变化(p>0.05);此外,0.6g/kg桉叶多酚组胸肌肌肉a*(红度)显著高于对照组(p<0.05),提高了23.40%;与对照组相比,0.6、0.9、1.2g/kg桉叶多酚组腿肌肌肉a*(红度)同样显著提高了24.52%、20.60%、23.07%(p<0.05)。在肌红蛋白组成方面,与阳性对照组相比,1.2g/kg桉叶多酚组显著提高胸肌肌肉中氧合肌红蛋白比例(p<0.05),提高了21.62%。在腿肌肌肉中,0.9g/kg桉叶多酚组肌红蛋白含量显著高于对照组,提高了25.10%(p<0.05)。在肌肉营养成分和脂肪酸组成方面,桉叶多酚各试验组对肌肉水分含量、蛋白质含量、灰分含量无显著影响(p>0.05)。0.9g/kg桉叶多酚组对胡须鸡胸肌、腿肌肌内脂肪均有显著提高作用(p<0.05),提高比例分别为34.50%和30.33%。0.6g/kg桉叶多酚组胡须鸡腿肌肌肉油酸相对于对照组显著提高了19.07%(p<0.05),0.9g/kg桉叶多酚组腿肌肌肉中亚麻酸的相对含量显著高于对照组和阳性对照组(p<0.05),提高了32.63%和37.42%;与阳性对照相比,0.6g/kg桉叶多酚组肌肉中饱和脂肪酸含量显著下降、不饱和脂肪酸显著增高(p<0.05),不饱和脂肪酸最高增加了11.95%;在风味成分方面,腿肌肌肉中0.9g/kg桉叶多酚组鸟苷酸含量显著高于对照组,提升了25.93%(p>0.05);0.6g/kg桉叶多酚组胸肌甘氨酸含量显著高于对照组和阳性对照组,均提高了8.81%(p<0.05)。相比于对照组,0.6g/kg桉叶多酚组和0.9g/kg桉叶多酚组胸肌组氨酸含量显著提高了13.24%和13.58%(p<0.05);1.2g/kg桉叶多酚组腿肌苯丙氨酸含量显著提高了8.50%(p<0.05);0.9g/kg桉叶多酚+阳性对照组腿肌组氨酸显著高于对照组,提高了13.85%(p<0.05);桉叶多酚可以改善肉色a*值,提高肌肉氧合肌红蛋白比例和肌红蛋白的含量,显著改善肉色;提高肌肉肌内脂肪含量,改善脂肪酸组成;同时,桉叶多酚提高肌肉中鸟苷酸、甘氨酸、组氨酸以及苯丙氨酸含量,改善肉质品质风味。(4)基于i TRAQ和RNA-seq技术对日粮添加桉叶多酚胡须鸡肌肉差异表达基因的筛选与注释。桉叶多酚组A0A0A0MQ61、GST、APOA4基因以及超氧化物歧化酶和过氧化物酶显著上调,能快速清除体内脂质代谢等产生的自由基,增强机体抗氧化性能;此外谷胱甘肽代谢通路中控制谷胱甘肽转移酶、谷胱甘肽水解酶、γ-谷酰基转移酶基因的表达量显著增高,提高机体中谷胱甘肽表达量,显著提高机体抗氧化能力,这与生理指标中GSH-Px活力显著提高相一致。桉叶多酚组肉色a*、肌红蛋白含量显著提高,这与本次组学中发现的代谢通路heme binding、hemoglobin complex以及hemoglobin binding密切相关,同时肉色相关的基因Mb显著上调表达,血红蛋白和肌红蛋白在肌肉内的含量受到基因或者特定蛋白调控,引起肉色的变化。长链脂肪酸运输、脂肪酸降解等代谢通路的变化引起肌肉中脂肪酸组成的改变;与氨基酸相关的代谢通路包括精氨酸和脯氨酸代谢等。更多还原

【Abstract】 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 γ-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.更多还原