Comparative evaluation of results of laboratory researches of milk in Kuzbass while carrying out control and surveillance measures for identifying false

Abstract

Milk is one of the main products of the consumer basket, a source of nutrients, and has specific characteristics due to its chemical and microbiological composition. Falsification of dairy products against the background of an increase in production cost dictates the need for quality control and sanitary and epidemiological supervision in the framework of protecting consumer rights and human well-being. The aim of the work is a comparative assessment of the results of laboratory studies of milk sold in retail of the Kemerovo Region (Kuzbass) during detection of falsification. Material and methods. In this work, using capillary electrophoresis, chromatography, voltammetry, spectrophotometric and titrimetric methods, the organoleptic parameters, fatty acid composition of cow's milk fat, mass fraction of fatty acid versus total fatty acids, the presence of vegetable fats in the fat phase, the ratio of the mass fractions of methyl fatty acid esters, acidity, mass fraction of dry skim milk residue (DSMR), density, phosphatase presence, mass fraction of fat, protein, purity group, presence of starch, soda, preservatives, the level of pesticides, aflatoxin M1, presence of antibiotics (penicillin, streptomycin and tetracycline group), microbiological indicators (total plate count, colifoms, pathogenic microorganisms, including salmonella, S. aureus, L. monocytogenes). The objects of research were coded samples of drinking pasteurized milk with various fat content, manufactured by enterprises of the Kemerovo Region, Moscow Region, Kazakhstan, Altai Territory. Results and discussion. In total, for 2017-2019, 258 samples of pasteurized drinking milk were studied, of which 11 samples did not meet the requirements of regulatory documents on physical-chemical and organoleptic quality indicators. In 11 rejected samples, the mass fraction of protein was underestimated by 25-50%, the DSMR by 8-13%, the density by 1-2%. In all inappropriate samples, deviations were established in the fatty acid composition of cow's milk fat and the proportion of vegetable fats in the fat phase (the proportion of phytosterols in the total sterol content). Increased acidity was detected in 1 sample. For one sample, the excess of the permissible negative deviation of the net content from the nominal quantity was determined. Thus, over three years, the share of products that do not meet the requirements of regulatory documents in terms of quality indicators, identified during laboratory tests, amounted to 4.3%. There were no inconsistencies with the regulatory requirements regarding the presence of phosphatase, purity group, the presence of starch, soda and preservatives. According to safety indicators (content of toxic elements, pesticides; aflatoxin M1 mycotoxin; absence of antibiotics, microbiological indicators) it was found that all samples met the requirements of Technical Regulations of the Customs Union 021/2011 "On food safety". Violation of the requirements for information on labeling was established for 15% of tested samples of dairy products. Conclusion. According to the results of the control and supervision measures in 2017-2019, 11 milk samples were rejected. At the same time, inconsistencies regarding mandatory labeling requirements were detected in 15% of samples, exceeding permissible negative deviations from the nominal volume was found in 0.3% of samples. Non-compliance for a number of indicators (density, acidity, etc.) was found in 4.3% of samples. There were no inconsistencies with the requirements of Technical Regulations of the Customs Union 021/2011 "On food safety".