Microbiological indicators of quality and safety of hard rennet cheese with linseed content during storage

Abstract

Food fortification is one of the most important processes for improving the nutritional quality and quantity of food products. Currently, the development of new recipes for dairy products is one of the driving forces of the dairy industry. The purpose of this study was to determine the suitability of the developed hard cheese with flax seeds for storage under the conditions defined by the standard. Microbiological studies were performed according to standard methods, which included the preparation of samples for the study, carrying out tenfold dilutions and sowing them on selective and storage media. Coliform bacteria and lactic acid microorganisms were determined according to DSTU 7357:2013, Salmonella and Listeria bacteria according to DSTU EN 12824:2004 and DSTU ISO 11290-1:2003, respectively. The developed Gouda-type hard cheese with flax seeds showed high microbiological indicators, which characterize its safety and quality, during storage at the temperature regime t... +5 ± 1 °C for 45 days. In particular, according to the amount of coliform bacteria, the product during 45 days of storage had a titer one order of magnitude higher than the maximum allowable limit (0.01 g), and according to the content of Staphylococcus aureus, it had an amount almost 20 times lower than the maximum allowable standard. Pathogenic microorganisms such as L. monocytogenes and Salmonella spp. were not detected in 25 g of the product during the entire storage period. At the end of the storage period, the number of lactic acid bacteria in the cheese was 8.0 ± 0.1 × 108 CFU/g. Therefore, the hard rennet cheese with flax seeds developed by us should show functional properties, both due to the content of flax seeds – a source of omega-3 fatty acids, and due to the vital activity of lactic acid microflora.