Examination of ready-to-eat food for microbial spoilage at room temperature and considerations about official refrigeration regulations in Switzerland [German]

摘要

21 samples of so called "highly spoilable" ready-to-eat foods (Confectionery, gourmet salads, sandwiches, meat products) were purchased on the local market. After having measured the initial core temperatures (9 to 16 degreesC), the products were stored in an incubator at room temperature (22 degreesC). To analyze microbial growth, counts of aerobic, mesophilic bacteria, Enterobacteriaceae and enterococci were measured at 0, 4, 8 and 24 h. The applied experimental approach showed that from the point, where core temperatures of 18-20 degreesC were reached (3 h), a bacterial growth of at most one log occurred after 5 more hours of storage. Based on the obtained experimental data, conclusions were made with regard to the tolerable interruption of refrigeration chains and temperature measuring-points (core of product or refrigerator). Furthermore, the Swiss regulation, which decrees that foods where a rapid growth of microorganisms at room temperature must be expected ("highly spoilable" foods) have to be refrigerated to 5 degreesC or less, was critically discussed. Consequently, it was suggested to give more flexibility to the the food producers with regard to the set up of storage temperatures. However, this proposal was linked to the restriction that particular storage conditions are based on adequate scientific data showing that products at the expiry dates or when sold to the consumers do not exceed mandatory, quantitative microbiological criteria.