Study On The Difference Of Nutritional Quality And Edible Quality Of Mutton Of Different Varieties And Parts In Hetian Prefecture

In this experiment,four breeds of meat sheep,Hu Sheep,Hetian sheep,Pishan red sheep and Small Tail sheep,which are housed in hetian prefecture of southern Xinjiang,are taken as research object,take its Longissimus dorsi muscles,shoulder muscles and gluteus muscle,to analyze and compare the edible quality,nutritional quality and volatile flavor substances of mutton of different varieties and different parts.To identify the differences in quality of mutton of different varieties and parts,It provides reference for evaluating mutton quality and efficient processing and utilization.The main research results are as follows:(1)Study on the difference of nutritional quality characteristics of mutton in different parts of different breedsComparing the nutritional composition of different varieties of mutton,it was found that the water content,fat content and protein content of Hu mutton and Small Tail mutton were higher than that of Hetian sheep and Pishan red sheep.Cholesterol content in mutton of different varieties and parts was lower than The national standard of 100 mg/100 g.The amino acid content of Hu mutton was the most abundant,and the total essential amino acid content of longissimus dorsi muscle was 230.52 g/kg,and the amino acid composition of small Tailed sheep and Hetian sheep was reasonable.Monounsaturated fatty acids were the main fatty acids in Hu sheep and Pishan red sheep,and saturated fatty acids were the main fatty acids in Small Tailed sheep and Hetan sheep.The unsaturated fatty acids proportions in longissimus dorsi muscle of Hu sheep,Hetian sheep,Pishan red sheep and Small Tailed sheep were 45.14%,33.31%,36.91% and43.59%,respectively.There was no significant difference in fatty acid content among the different parts(P>0.05).From different parts,gluteus muscle had less fat content and higher water content,and the protein content in longissimus dorsi muscle was significantly higher than shoulder muscle and gluteus muscle(P<0.05),but there was no significant difference in amino acid content of other three kinds of mutton except Pishan red sheep(P>0.05).(2)Study on the difference of edible quality characteristics of mutton in different parts of different breedsThere were significant differences in p H values among different breeds(P<0.05).Hu sheep and small Tailed sheep had better color and lower cooking loss rate,and Hetan sheep and Small Tailed sheep had lower tenderness.The longissimus dorsi muscle had bright color and small cooking loss,but the shoulder muscle had significantly lower shear force than the other two parts(P<0.05)and better tenderness.In the TPA test,there were significant differences in hardness and chewiness among different varieties and parts(P<0.05),but no significant differences in elasticity and cohesion(P>0.05).In conclusion,the longissimus dorsi muscle of Hu sheep and Small Tail sheep is of better edible quality,followed by shoulder muscle.(3)Difference analysis of flavor characteristics of mutton in different parts of different breedsHeadspace solid phase microextraction coupled with gas phase mass spectrometry and chromatography(SPME-GC-MS)was used to determine the flavor compounds in muscle.A total of 133 effective volatile components were detected in muscle,including aldehydes,acids,alcohol,ketones and so on.The content of substance species in muscle of Hu sheep was significantly higher than that of other breeds(P<0.05),but there was no significant difference in the content of flavor substances in muscle of different parts(P>0.05).Principal component analysis and cluster analysis were used to analyze common compounds.The main substances affecting the flavor of mutton were myristic acid,E-2-decyl olefine aldehyde,2-undecenal,3-methyl butyral and so on.These substances were the main substances constituting the flavor of mutton and had the strongest influence on the aroma of mutton.Hu sheep have high content of these substances,rich aroma and good flavor quality.(4)Preliminary study on fatty acid fingerprint of mutton in different parts of different breedsThe chromatographic fingerprint similarity evaluation system software was used to establish the corresponding fatty acid standard fingerprint,and similarity analysis was carried out.It can be proved that the standard fingerprint can represent the integrity of samples,and there are differences in fingerprint similarity between different samples,indicating that the fatty acid standard fingerprint can reflect the overall difference between different breeds of mutton sheep,and can be used to distinguish different breeds of mutton sheep.