Study On Establishment Of Risk System Of Preservative In Raw Milk

Milk is a nutrient food,which is riched in protein, unsaturated fatty acids, minerals and vitamins,but it is also a good medium for microbial propagation. The number of bacteria in raw milk can easily happen in a substantial increase in the process of milking and storage because of the poor sanitation in the process of cows breeding and inadequate cooling insulation equipment and measures in the present of our country. In order to maintain a good quality of dairy products,processing enterprises price the raw nilk according to the quality. The total number of bacteria is one of the indicators that determine the price between enterprises and farmers. So preservatives may be added illegal in the production process to inhibit the reproduction of bacteria in raw milk to maximize the benefits. Although the good effect of chemical preservatives, they exist potential harm to the human body, especially do great harm to the infants under the condition of excessive consumption.Therefore,it is significant to research how to control the chemical preservatives in the raw milk for healthy development of the dairy industry and ensuring the health of the people.Firstly,a simple and reproducible reversed-phase(RP)high-performance liquid chromatography(HPLC)method for determination of sodium thiocyanate in raw milk was developed and validated in the paper.Samples were dissolved with warm water, extracted with Ultrasonic, and the precipitation of protein with Zinc acetate and potassiμm ferrocyanide. Separation was performed on C18colμmn at30℃using an isocratic mobile phase of Phosphate buffer-Acetonitrile (95:5,v/v)and a flow rate of0.8mL/min, Detection wavelength was at218nm. The detection limits was0.484mg/kg,the relative standard deviations of repeatability were1.55%, and average recovery was82.28%. The method showed desirable values for precision,recovery and sensitivity.and proved very simple for routine analysis work.Secondly, the content of benzoic acid, potassium sorbate and sodium thiocyanate in raw milk were statistically analyzed. According to the detection result, all the samples that detected contains no potassium sorbate,while the content of benzoic acid and sodium thiocyanate were within the normal range, which can exclude the possibility of artificially added.The content of benzoic acid in raw milk ranged from2.03to10.48mg/kg,and it existed significant differences in two different cows breeding pattern,which the large-scale farming has lower levels than idividual dairy farmers.The whole powder from different places and infant formula existed amount of benzoic acid,but it is within the normal range.The content of sodium thiocyanate in raw milk ranged from2.19to5.06mg/kg.and the content of sodium thiocyanate in the raw milk existed significant differences in two different cows breeding pattern,which the large-scale farming has higher levels than idividual dairy farmers. The whole powder from different places and infant formula existed amount of sodium thiocyanate,and it is also within the normal range.Furthermore, the factors that affected the quality of raw milk were analyzed.Season,the number of the initial bacterial, temperature and storage time significantly affected the number of bacteria in raw milk. According to the analysis of significant factors that affected the total number of bacteria and the use of decision tree analysis method, the Critical Control Point for controlling the quality of raw milk were cows breeding and disease management, milking,storage and transport of raw milk detection of raw milk quality and pricing of raw milk.Finally, the applications of RFID and cloud computing technologies in raw milk hygiene quality control HACCP system was realized. Under the help of raw milk hygiene quality control system that are supported by RFID and cloud computing technologies, Cows breeding and milking were guided based on the amount of milk that produced and the quality of raw milk; the time and temperature of raw milk in the storage and transportation of raw milk are monitored; the sampling indicators and detection frequency are determined depending on the credit rating and historical quality information of dairy farms;the purchase price of raw milk are determined based on physical and chemical indicators of raw milk.Dairy farmers can easily understand the quality of the milk selection of pricing parameters and pricing manner with the help of Construction of Information Service Platform of raw milk;Dairy companies can adjust acquisition criteria and valuation parameters according to the received quality data statistical of raw milk;The department of quality management adjust its limits based on statistics of various indicators in raw milk. Consumers selected cost-effective dairy products according to the inquiry of sources and quality of dairy products that they buy.