【作者】 王衍彬；

【导师】 叶兴乾；

【作者基本信息】 浙江大学 ， 食品科学， 2003， 硕士

【摘要】 超声乳成份分析仪(Ultrasonic milk analyzer)由浙江大学食品系根据超声波原理研制，可以迅速检出牛乳蛋白、脂肪、固形物、掺水量、密度和冰点。本课题研究了超声快速乳成份分析仪的稳定性和准确性，常见的乳中掺假物对乳成份分析仪测定的影响，其研究结果与FOSS乳成份分析仪(FOSS milk analyzer)和国家标准方法(GB)的分析结果相比较。主要结论如下： 超声乳成份分析仪对原料乳成份的检测结果显示，超声乳成份分析仪的准确性与重复性都比较好，可以在原料乳成份检测时用它来代替国标检测方法。超声乳成份分析仪的测定结果随温度上升而有所升高，但在25℃—35℃之间升幅较小，所以使用时必须将温度控制在此范围之内。 超声乳成份分析仪可以直观显示牛乳的掺水率，但在掺水量超过20％时，蛋白、脂肪、固形物和密度数据会有一定的偏差。掺水量为20％时，超声分析仪的数据比国标数据约高5％左右。 乳中掺加蛋白粉，国标方法、Foss分析仪和超声分析仪的蛋白数据都会上升，上升幅度超声分析仪明显小于前两者。加脲对超声乳成份分析仪的蛋白数据基本无影响，对掺水率数据影响也较小，但会使其固形物和密度数据上升。 掺加植脂末，会使超声分析仪的脂肪数据上升，其升幅远小于国标方法，但掺加植脂末对超声分析仪的掺水率测定影响较大，掺加3.4％植脂末即可抵消10％的掺水量。 乳中掺蔗糖和食盐会使超声分析的检测数据异常上升，且升幅较大。每增加1.2％的盐，蛋白数据平均增加1.5％左右，固形物数据平均增加4％左右；每增加0.6％的蔗糖，蛋白数据会平均增加0.2％，并可抵消10％的掺水量，但对脂肪数据基本无影响。根据乳成份的均衡性，可以利用超声分析仪判断乳中食盐和蔗糖的掺假情况。更多还原

【Abstract】 Ultrasonic milk analyzer is designed by Zhejiang University for fast and effective analysis of fat content, milk solids non fat (SNF), protein, milk density, freezing point and added water in milk as well for raw milk,. The principle is based on changes of ultrasonic physical properties when ultrasound moved through milk. This study was done to made an investigation on ultrasonic milk analyzer’ s characteristics, analyzed the influence of milk adulterations on this instrument. The results were compared with that from the Foss 134 infra milk analyzer and standard methods(GB). The main results were as follows:Ultrasonic milk analyzer has its high stability, accuracy, and good repeatability. The data showed that it had not great difference with that from standard milk analysis technology(GB). The measured data of the Ultrasonic milk analyzer increased with the temperature rose, but the deviation was very small within which showed that the Ultrasonic milk analyzer should operate under this condition.Ultrasonic milk analyzer could indicate the adulterated water ratio directly, however, when the adulterated water ratio is about to 20%, its data was more than 5% nearly compared with that of GB milk analysis technology, and when the ratio was beyond 20%, its measurement had deviation to some extent.The protein detected by these three methods increased a little, when hydrolysed animal protein powder was added in raw milk, but the protein detected by ultrasonic milk analyzer was smaller than that of the other two analysis technology obviously. When raw milk was adulterated with urea ,protein measured by ultrasonic milk analyzer and the adulterated water hadn’ t change in general, but the SNF and density rose.When raw milk was adulterated with non-dairy creamer, fat measuredby ultrasonic milk analyzer increased, but its amplitude is smaller than that of GB milk analysis technology, and the adulterated water ratio was as affected too. When raw milk contained 10% added water was adulterated with 3.4% no-dairy creamer no added water would be appeared in the analyzer.When cane sugar and table salt were added in raw milk, all parameters measured by ultrasonic milk analyzer increased greatly. When 1.2% table salt was added to milk, the protein increased about 1.5% averagely, the SNF increased 4% averagely; When 0.6% cane sugar was added to milk, the protein increased about 0. 2% averagely, at the same time, it counteracted the content of 10% adulterated water. No influence was observed on the fat when the milk was adulterated by cane sugar. According to the proportionality of milk components, ultrasonic milk analyzer could be utilized to detect the adulteration of cane sugar and table salt in raw milk.更多还原