Development Of A Portable And Fast Instrument For The Detection Of The Total Amount Of Bacteria In Milk

In recent years, a lot of milk poisoning events have taken place in China. Investigation shows that a major cause of milk poisoning is that the raw milk is heavily polluted and the total amount of bacteria greatly exceeds the national standard. In order to cut down the incidence of milk poisoning, the quality of the raw milk must be strictly controlled and the total amount of bacteria must be detected. However, at the present, the detection methods of the total amount of bacteria available in China have the shortcomings of complex operation and long detection period. They are mainly used in the inspection of finished dairy products rather than the detection of the raw milk. Although the advanced detection machines overseas are fast and easy-operating, they are too expensive and the detection expense is too high. There are only about ten large dairy enterprises in China using such machines in their detections, while the small-and medium-size enterprises cannot afford either the high cost of the machines or the high detection expense at all.In view of this situation, a portable and fast detection instrument for the total amount of bacteria in milk is studied in this thesis. Based on the color-changing feature of resazurin, utilizing the color change data of milk measured by image sensors, we build the relation between the total amount of bacteria in milk and the color change by mathematic software. And we completed the hardware and software designs of the main modules of a portable and fast detection instrument for the total amount of bacteria in milk. In detections, the DSP core processor can give out the detection result by the relation and show the result on the extended display device. Consequently, we achieved the fast detection of the total amount of bacteria in milk.The experiment results show that the instrument can give out qualitative detection results at a fast speed, and the detection expense is rather low. This enables it to be easily adopted by the small-and medium-size dairy enterprises. Consequently, the quality of the raw milk can be strictly controlled, the production of problematic dairy products can be decreased, and the incidence of milk poisoning can be cut down.