Hazard Analysis And Safety System On The Food Chain Of Environment-forage-yak Meat/Milk Products In Tianzhu

Taking the food chain of environment-forage-yak meat / milk products in Tianzhu as the object, the existing of pathogenic germs, fungi, heavy metals and remains of farm chemicals, and furthermore, their moving, distribution and transferring were studied quantitatively. The whole system of white yak's environment(soil, atmosphere, water) — forage ( summer / autumn and winter / spring forage grasses and major shrubs)—yak meat / milk products( raw materials and processed foods) were sampled and determined. All the data were processed and analyzed with multiple element variables, and then regressive equations were induced. The harm source and feature of the system were confirmed and the ways and means of pollution were evaluated. Finally, the HACCP safety control system of the food chain was set up. The results are as follows: (1) White yak meat has the characteristics of high protein, high fats, high energy and rich minerals. It contains about thirty-eight kinds of volatile compounds, in which about eight contribute greatly to the flavoring of yak milk. The white yak meat and milk are really genuine nutrient resources and high value of economy. (2) In the experimental area, some indices of pH, Pb, Cd, As, CODcr and BOD5 from the surface and ground water have not exceeded the prescriptive value. It shows that the pollution level is clean and the water source has not been polluted. The daily concentration of atmospheric pollution TSP at Tanshanling, Shimen, Songshan and Tianrun company just accord with the national standard. Excepting for Zhuaxixiulong, Datan, the other places all have serious pollution of suspending granules. SO2 and NOx have not exceeded the national standard in all atmospheric samples existing multiplex contamination. The SO2- NOx correlated significantly (P<0.05). The order of the synthetical pollution of atmosphere is Tanshanling (1.870) >Tianruncompany (1.343)>Songshan(1.156) >Shimen (1.085)> Xida- tan(0.602)> Zhuaxixiulong (0.450).According to synthetical determinant, the pollution grade of Tanshanling, Tianrun company, Songshan,Shimen is light and pollution level is cautionary level; the pollution grade of Datan and Zhuaxixiulong is clean and pollution level is within the limiting standard.Heavy metals of the soil have not exceeded the standard, but they have the accumulation in the largish degree. It expresses that the safe has exist some risk. As result of existing multiplex contamination, the experiment shows that Pb- Cd and Cd- As exsit the significant correlation(P<0.05). The order of the synthetical pollution of the soil heavy metals is Tanshanling (0.848)> Shimen(0.729) > Songshan(0.602)> Datan (0.496) > Zhuaxixiulong (0.466), the pollution grade of Tanshanling, Shimen is cautionary line, pollution level is clean. The organic chlorin pesticide in the soil, the organic chlorin and the organic phosphorus pesticide have not determined. It shows the pollution of the grassland is extremely light. (3) The pollution degree has something to do with mineral miner of zinc ore, gypsum, lime and coal, main direction of wind and dust declining from atmosphere, traveling and transportation, etc. Pb, As and Cd in summer-autumn grass haven't exceeded the standard, the order of the general pollution degree is Tanshanling (3.646) > Shimen (2.572) > Songshan (1.248) > Zhuaxixiulong (0.714) > Datan (0.588). Significant correlation relationship existed between Pb and As. The grass quality of Tanshiling and Shimen is belong to the secondary grade, and the rudimental pollution of grass is much more serious. The rest is high-grade. Pb, As and Cd in winter-spring grass have not exceeded the standard, the order of the general pollution degree is Songshan (2.754) > Tanshanling (2.719) > Shimen (2.716) > Datan (2.568) > Zhuaxixiulong (2.547). It exists low correlation between Pb, As and Cd. The grass quality belongs to a secondary grade, and rudimental pollution from grass is much more. Pollution in winter and spring is higher than pollution in summer and autumn. Absorbing coefficient of heavy me...