Research On Nutrition And Pathogenic Microbes In Meat And Milk Of White Yak

This paper makes the raw material of meat and milk and products of meat and milk of Tianzhu white yak as object, and adopts assessment method of meat quality to assess white's meat quality and advanced assay metod of nourishing ingredients in meat and milk of white yak to analysis nourishing ingredients of white yak's meat and milk. It also adopts advanced microbe assay method to mensurate pathogenic microbes and toxin pollution in meat and milk of white yak. The conclusions obtained from the research have important significance to prevent meat and milk from polluting pathogenic microbes, ensure that the products of meat and milk become real green foods and keep people and society economy from harming. Besides, it can also provide some scientific conclusions for setting up HACCP management system of white yak and promoting to exploiture green foods of white yak's meat and milk. The results show as follows: Compared with contrasts, white yak's meat quality is better. It has the characteristics with higher protein(21.87g/100g, P<0.05), lower fat(1.79 g/100g,P<0.05) and abundant mineral materials,especially iron (6.60 mg/100g,P<0.01). Total amino acids are higher (19.702 g /100g). Essential amino acid content was 7.520g /100g. The rate of essential amino acids content and total amino acids content was per 38.17. MET+CYS and TRP were limiting amino acids. The nutrition of white yak's milk is abundant. Compared with contrasts, it has the characteristics(P<0.05,P<0.01) with higher protein(6.19g/100g,p<0.01), higher fat(5.90 g/100g,P<0.05) and calcium content was quite high(133.30mg/100g,p<0.01). Essential amino acid content was 2.41 g/100g, and the rate of essential amino acid content and total amino acids content was per 39.90. MET+CYS and TRP were limiting amino acids. The assay rate of seven enteropathogens in raw meat were: staphytococcus aureus (22.58%) >Escherichia coli (12.92%, aggressive O136, pathogenic O128), Staphytococcus aureus was detected only in productions from Shimen (12.50%). The pollution degree of Shimen was the most serious among four sampling spots. Staphylococcus enterotoxias were sequently qualified:C(9.68%)>A,B(6.45%, respectively) >E(0%); Enterotoxias pollution of Shimen was the most serious among four sampling spots. The pollution degree of fungus in raw meat is Dongdatan(78) > Dalong(77) > Tanshanlin(66) > Shimen(25). The toxic fungus detected in raw meat were: Aspergillus versicolor Tiraboschi, Penicilliune cyclopium Westing, Cephaeosporium reseum Oud. The assay rate of seven kinds of entercpathogens in raw milk were staphytococcus aureus (31.58%) >Salmonella (10.52%, enteritis ) >Shigella (5.26%). The assay rate of seven kinds of entercpathogens in disinfectant milk were staphytococcus aureus (5.26%) >Salmonella (2.63%), the pollution index of staphytococcus aureus on spots was as following: Shimen > Tanshanlin,Dalong > Dongdatan; Shigella was only detected in Shimen; Salmonella was detected in all sampling spots. Staphylococcus enterotoxins were sequently qualified in raw milk: A (10.53%)>B and C (5.26%); Enterotoxias pollution of Shimen was the most serious among four sampling spots. The pollution degree of fungus in raw milk is Tanshanlin(8.9×104) > Shimen(3.4×104)>Dalong(2.7×104) >Dongdatan(2.5×102). The toxic fungus detected in raw milk were: Fusarium, Pericillium cyclopium Weslting and Mucor Mideli Ex Frie.