The Study Of Raw Milk Safety Detecting Technology

In recent years, an endless stream of security events dairy products, dairy products adulterated incidents frequently occur, seriously endangering the health of our people and even cause death, therefore, several methods was studieds to determine wether the raw milk was adulterated to stop dairy products adulterated from the source in the paper.The freezing point of raw milk will remain at a stable range and the range was narrow, so the determination of freezing point of raw milk can be used to determine whether the watered milk objective basis, when mixed with water or other impurities the freezing point of raw milk will change, so if we determine the freezing point of raw milk, we can find out whether the raw milk mixed with water, and can find out the watering quantity by calibration curve. Lactose is an endemic element in the raw milk, as long as the source of the lactoce is determined, the content of the lactose in the milk is within a certain range, after adding adulterated the content of the lactose will change, by measuring the lactose content of raw milk can directly derive wether the Milk is adulterated. In this paper, used milk as an example, we studied the effects of the water content on freezing point of raw milk, the optimum conditions and the reliability of Lane-Eynon, Colorimetry and Conductometric biosensorcolorimetric.The calibration curves were liner for freezing point(-0.516～-0.533℃) and watering content, the linear regression was y=0.0056x-0.5211, correlation coefficient was 0.9987, the result of the repetitive experiment was 0.604%, the result of the milk blind samples was consistent with the actual, and there is little effect of after adding water adding sucrose, glucose or melamine to adjust the proportion on the increased value of freezing point caused by adding water. So we can determine the freezing point of the milk to find out wether mixed with water and mixed how much water.The pricision of the Lane-Eynon was 0.398%, the repeatability was 1.374%, the average recovery was 100.338%, the result of the milk blind samples was consistent with the actual, so it is feasible to determine the content of lactose in the raw milk.The linear regression of the colorimetry was y=0.2284x+0.001, correlation coefficient was 0.9992, the pricision 0.55%, the repeatability was 1.46%, the average recovery was 99.56%, the result of the milk blind samples was consistent with the actual, so we can determine the freezing point of the milk to find out wether mixed with water.In the test of conductometric biosensor, mutagenically voltage is 1.2V. The linear regression was y=0.0655x-0.0874, correlation coefficient was 0.9925, the pricision 1.603%, the repeatability was 2.805%, the average recovery was 100.258%, the methord is accurate and of good reproducibility, the Micro-current Determinator is also accurate. Suggested adding 10mL precipitants when determine the raw milk. The current can be stability in about 5min, the time is short, and can be used for the determination of high-volume products, but because of there are some organic in the milk systerm, the conductivity of the solution was reduced. Compared with the results of Lane-Eynon and Colorimetry which are 45.488mg/g and 45.8295mg/g, the measured value is a little small, recommended during the determination of lactose using the difference as the currented value, therefore, suggested that determining the currented value by large mount of experiments in future...