Only 10 years ago, the study of the quality of milk and dairy products was possible only in the conditions of laboratories. The analysis process was rather time-consuming, required highly qualified staff, could take up to 15 hours. The development of technology has radically changed the situation. Modern methods of express analysis, thanks to the introduction of new methods, help to carry out research an order of magnitude faster, not so dependent on the qualifications of personnel with high accuracy in determining the parameters.
There are several different methods for studying the quality of milk and dairy products based on different principles, but providing high accuracy and speed of analysis. The necessary equipment is made by both foreign and domestic manufacturers. Models of various productivity are calculated on use in farms and big laboratories.
The modern class of equipment includes infrared spectrometers. These are high-performance devices that provide high-quality, fast examination of samples with a minimum amount of preparatory work. Such express analyzers are equipped with interferometers operating using the Fourier transform theory. Their action is based on scanning the spectrum of the middle infrared range. To analyze the spectrum obtained, special software is used, which ensures the reliability of the results at the level of 99%.
Infrared spectrometers are great for large enterprises that buy milk from farms. With their help, you can not only determine the content of impurities, but also to determine exactly what substance was added. The analysis process takes an average of 1 minute.
Equipment that uses the principle of infrared analysis provides an assessment of the entire range of dairy products. For the study also used the method of diffuse reflection using the integrating sphere. Thus, quality is assessed:
- sour cream;
- cottage cheese products;
As you can see, it is possible to analyze both pasty and solid samples, as well as liquid products. IR analyzers combine:
- ease of use;
- high accuracy;
- management, understandable at an intuitive level.
Devices operating on the principle of analysis of the infrared spectrum, produced in different price categories, depending on the number of additional functions and performance.
Ultrasound based analyzers
The second common method for the study of milk and dairy products is ultrasound. It is based on a clear dependence of the speed of propagation, as well as the degree of absorption of milk ultrasound, depending on its composition. Thus determine the amount of fat and dry fat-free substances. It was experimentally proved that at a temperature of 14 ° C the speed of sound propagation in the dairy environment is not determined by the mass fraction of fat, but depends on the content of SOMO.
To analyze the fat content, the milk is heated to 50 ° C and an amendment is introduced, which is determined by the amount of dry skimmed residue. With the help of ultrasound, analysis of the content in milk is available:
Ultrasonic devices provide accurate measurement of fat content at the level of 0.1%. The required time for analysis is on average 1.5 minutes.
Alternative and promising methods for the study of milk
Ultrasonic and infrared analyzers have proven their effectiveness, but the development of technology does not stand still. The developers are trying to investigate the qualitative composition of milk by other methods. The most interesting and promising of them is the use of the nuclear magnetic resonance (NMR) effect. Its indisputable advantage lies in the non-invasiveness and non-destructiveness of samples in the course of research.
Using NMR analyzers, it is easy to control the quality of dairy products. Their action is based on the fact that the water protons have a relaxation rate of 1 / T2 proportional to the protein content. Thus, rather quickly and without time-consuming preliminary preparation of the sample, it can be examined for the content of casein (the main milk protein):
- cottage cheese;
- condensed milk.
The accuracy of research using the effect of nuclear magnetic resonance varies within 0.5%. This is slightly higher than that of ultrasonic and infrared counterparts, but in some cases, ease of use of the device and the speed of the study is more important.
Modern methods and hardware for determining the quality and composition of dairy products are simple and reliable, guaranteeing high accuracy of the parameters obtained. They greatly facilitated the task and helped to ensure the possibility of conducting research outside the laboratory. Today, such an analyzer can be purchased and used in any farm for its own quality control of products.