| With the quickly improvement of living standards, there is more concern about the quality and flavor of muscle produces.As an important factor of flavor, people pay more attention to the study of volatile flavor compound. In recent years, study on volatile flavor compound had made great progress, which mainly concentrated on characteristic volatile flavor compounds. It is widely believed that different feeding ways can affect the flavor of broiler, free-range can improve the flavor of broiler because of eating the natural feed. However, how about other factors on the process of form volatile flavor compounds? It is necessary to study the volatile flavor compounds for broiler.In this study, we mainly studied the effects of the three feeding ways including feeding in cages over the ground, feeding in cages on the ground and semi-feeding on production traits, meat quality traits and flavor substances. The mechanism of muscle volatile flavor compounds was also studied under feeding age, storage temperature and other aspects. The main content and results were as follows:(1) The experiment was about the effects of the three feeding ways on production traits, meat quality traits.900Beijing-You chickens are raised to49daays before be apart into different feeding way. A total of nine hundred49-day-old healthy Beijing-you chicken were randomly assigned to one of three housing systems:cage-rearing floor-rearing without outdoor access and floor-rearing with outdoor access. Five pens were placed in a rearing pattern containing thirty birds in each sex, and a pen was a replicate.The feeding period lasted91days.On the49th day,63rd day,77th day and91st day,3males and females were choose to get the data of production traits and meat quality traits. The results show that the average daily gains and the percentage of abdominal fat of semi-feeding were significantly lower than the feeding in cages and the feed conversion ratio was significantly higher. There was no change on meat quality traits.(2) The experiment was about the effects of feeding ways on muscle volatile flavor compounds. On the91st day,3males and females of the three feeding ways were choose to detect fatty acids, inosine acids and volatile flavor compounds. The results show that the fatty acids, such as Palmitic acid C16:0, palmitic acid C16:1, heptadecanoic acid C17:0, heptadecyl an acid C17:1, oleic acid C18:In9c, linoleic acid C18:2n6c, eicosanoids C20:0and inosine acids were significantly higher of semi-feeding than the feeding in cages(P<0.05) and cis-10-eicosapentaenoic acid C15:1, stearic acid C18:0, trans linoleic C18:2n6t, arachidonic acid C20:4n6were higher of semi-feeding than the feeding in cages(P <0.05).77species of volatile flavor compounds were detected. The numbers of semi-feeding were63and65for males and females, respectively. The numbers of feeding in cages on the ground were68and58for males and females, respectively. The numbers of feeding in cages over the ground were62and53for males and females, respectively. The species of aldehydes and hydrocarbons were more in males of semi-feeding and feeding in cages on the ground, only in females of semi-feeding. The ketones were significantly higher of semi-feeding than the other two feeding ways.(3) The experiment was about the effects of age on muscle volatile flavor compounds. On the63rd day,77th day and91st day,3males and females were choose to detect the compositions and contents of volatile flavor substances. The results show that the species of volatile flavor substances were growing with age increasing. The ketones, esters and heterocyclic compounds increased significantly. Compared the three feeding ways, the relative contents of various species of compounds of semi-feeding and feeding in cages on the ground did not change significantly. The relative contents of aldehydes of feeding in cages over the ground increased, while the relative contents of alcohols and hydrocarbons reduced.(4) The experiment was about the effects of storage temperatures on breast muscle volatile flavor compounds. Fresh broiler breast muscles were divided into18parts after rubbed and stored at4℃,-20℃,-50℃. The results show that volatile flavor compounds in muscles stored at-50℃were most with62species, followed by that stored at-20℃and4℃, which were57and46species. Different storage temperature also affect the relative content of volatile flavor substances. When stored at-50℃, the highest relative contents of muscle were ketone compounds. The relative contents of aldehyde compounds were the highest and the ketones and hydrocarbons levels were relatively high when stored at-20℃and4℃.In conclusion, the effects of the three feeding ways on production traits, meat quality traits were not significant. But the compositions and contents of muscle volatile flavor compounds were changed by different feeding ways though physical activities and maintenance needs. Ages and storage temperatures had effects on the compositions and contents of volatile flavor compounds. |
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