Research On The Quick Measurement Technique Of Fresh Milk Protein With The Method Of Laser

In this paper, we theoretically and experimentally discussed the measurement technique of the concentration of protein in fresh milk through laser scattering theory.The high measuring accuracy of the concentration of protein in milk is required. Tn order to eliminatc the error caused hylight power drift of incident light, we adopt the method of the ration of scattering light to measure the concentration of protein in milk. That is to measure 90" scattering light intensity and 0" transmitting light intensity in the light incident plane. The ratio of them is to be used to express measured optical parameter. In the milk, there are two kinds of large scattering molecules: fat and protein. It is almost impossible to find a kind of dissolution liquor which can dissolve fat quickly, only protein existing. If eliminating fat is slow, it deviates our destination of designing the quickly measuring instrument. So, we must measure the protein in milk directly. Using the single frequency light to measure the protein in milk directly is vacant internationally. From 1950's, light scattering theory has been applied to measure fat in milk and the instrument was also made, but not used commonly for some problems. In the past half century, the research of using this theory to measure the concentration of protein in milk has not been successful, which is the key reason of not inventing multi-ingredient milk measuring instrument by this theory. Through numerous experiment and analysis of scattering characteristic about fat and protein in milk, we find their characteristic about fat and protein in milk, we find their scattering law and establish the correlative scattering model of fat and protein in milk. Especially, we adopt surface fitting to break through this problem from theory and technology, without isolating protein from milk, we can directly measure the protein in milk, that is to say, completely realizing the quickly accurate measurement of protein in milk. Furthermore, we bring prosperity for the field of measuring multi-ingredient in milk through light scattering theory. Also, the research field of measuringmulti-ingredient can be based on this theory.In present, our country's milk industry is very backward contrary to the developed nation. The monitor of milk quality is one of the most fragile moment. From these, we can say that the successful development of quickly measuring instrument of protein in milk will make great contribution for promoting the progress of our country's milk industry and improving milk quality. It would have widen market prosperity, huge economy and social profit. Especially, after our country entry into WTO, the instrument will be great meaningful for enhancement of international competence of our country's milk industry.