Microbiological Contamination of Food Raw Materials and Ready-To-Eat Foods: Analytical Review

Microbiological contamination changes the qualitative and quantitative profile of food, which makes it an important issue of food safety systems. Finished products with components of animal origin or combined vegetable and livestock raw materials are especially prone to microbiological contamination. This review features the most common sources of microbiological contamination and its prevention in finished products. The review covered 20 years of English and Russian scientific articles and standards indexed in Scopus, ScienceDirect, PubMed, and eLIBRARY.RU. The descriptors included microbiological contamination, food raw materials, and ready-to-eat products. The analysis involved some older publications, provided they possessed a high scientific relevance and/or a high citation index. The search criteria concentrated on the detection of microbiological contaminants in food raw materials and food products in Russia and abroad. The percentage of detections for individual groups of microorganisms was calculated as opposed to their total number. The data obtained can be summarized as follows. Regular industrial monitoring can minimize the risk of microbiological contamination. Complex finished products have a higher risk and require heat treatment. Composite products that cannot be succumbed to additional heat treatment need new technologies that minimize microbiological contamination, e.g., intensive cooling, shock freezing, electromagnetic processing, protective food coatings, etc. Even a small amount of animal raw materials may cause extra risk of contamination with Listeria monocytogenes, Salmonella enteritidis, etc. A mix of different raw materials changes the microbiological profile of the finished product. As a result, finished products have to be monitored throughout the entire shelf-life cycle, regardless of the percentage of animal raw material in the formulation.