【作者】 侯志灵；

【导师】 于助；

【作者基本信息】 哈尔滨理工大学 ， 材料物理与化学， 2003， 硕士

【摘要】 本论文从理论和实验上详细研究了利用激光散射原理快速测量牛乳蛋白质含量的测定技术。 由于牛乳蛋白质的测量精度要求很高，为了消除因入射光的光功率漂移而引起的误差，我们采用散透比法来测量牛乳蛋白质的含量，即在光的入射平面内同时90°处的散射光光强Is和测量0°处的透射光光强It，用它们的比值来表征测试牛乳蛋白质含量的光学参量。因为牛奶中含有脂肪和蛋白质两种散射大分子；而且由于无法先用一种快速溶解液将脂肪快速溶解掉而只剩下蛋白质，如果用一种较慢的方法除去脂肪，就脱离了我们设计快速测试仪的初衷。因此只能直接测量牛乳这一复合体中的蛋白质，而利用一种单色光直接测量牛乳这一复合体中的蛋白质在国际上尚属空白。从上世纪五十年代起，就有人利用光散射原理测量牛乳脂肪的研究，并有仪器出现(只是由于这种仪器存在问题而没有普及)。但是半个世纪以来利用该原理测量牛乳蛋白质的研究却始终没有成功。这是迄今没有利用该原理研制出牛乳多成份测试仪的关键所在。经过大量实验和对牛乳脂肪蛋白质的散射特性分析，我们找到了他们的散射规律，并建立了牛乳脂肪和蛋白质的关联散射模型，并采用多元线性回归的曲面拟合法彻底突破了这一难关，无需把蛋白质从牛乳中分离出来，可直接对牛乳这一复合体中的蛋白质进行测量，完全实现了快速而准确的牛乳蛋白质测试，为利用光散射原理同时测量牛乳多成份这一研究领域开辟了光明而广阔的前途。同时也为将该理论应用于同时测量多种成分物质的研究领域奠定了基础。 由于我国乳品工业与发达国家的差距仍然十分明显，而且牛乳的质量检测是最薄弱环节之一，因此牛乳蛋白质快速测定仪的成功开发，对促进我国乳品工业发展，提高乳品质量会带来巨大贡献，它有广阔的市场前景和很大的社会、经济效益。尤其在加入WTO后的今天，为增强我国乳品工业的国际竞争力，具有重大现实意义。更多还原

【Abstract】 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.更多还原