METHOD OF RAPID REMOTE CONTROL OF CASEIN CONCENTRATION IN DAIRY PRODUCTS IN UNOPENED PACKAGES

We propose a new nuclear magnetic resonance (NMR) method of rapid remote determination of casein concentration in dairy products in unopened packages. The method was successfully tested for whole milk products in unopened packages. The milk products had a fat concentration in a range of 0-6%, casein concentration in a range of 0-3% and were produced by different manufacturers in Leningrad Region, Russia. Because the milk packages had different sizes and shapes, we used a new receiver magnetic resonance imaging (MRI) solenoid that has a variable radius and shape for an improvement of signal-to-noise ratio of MR images of milk products measured in MRI system, GEMS Vectra, 0.5 T. Practical ApplicationsThis method may have two possible ways of practical implication. Using this rapid remote method, the adulteration of casein concentration in dairy products particularly in sealed packages can be detected, e.g., milk, condensed milk, cottage cheese produced with the use of adulterated skim milk powder containing whey powder. According to the preliminary estimation, the minimum casein concentration recorded with the method proposed is less than 0.5%. The method is based on measuring the water protons spin-spin relaxation time 1/T-2, which is proportional to the number of hydrogen atoms bound to casein micelles due to chemical exchange and hydration. Therefore, the method may be used for research purposes of casein micelles hydration processes that influence vastly the stability of the micelles in the milk protein, the structure and mechanical properties of protein coagulum formed in the production of sour milk products, the consistency of the finished cheese. Therefore, this method that uses NMR imaging could be used for remote research of the spatial distribution of hydration parameters (hydration properties, the mobility of water in the hydration shells, etc.) in the foods that are produced and kept in sealed containers, and of storage control quality.