Microbiological quality of vacuum-packed pork meat: The influence of different technological factors on lactic acid bacteria growth

Environmental conditions provided by the preservation method are essential for the microbes to grow. Since the spoilage level is a count of microbes, essentially any microbe that is on the food product and can reproduce enough numbers can spoil the product. However, there are specific organisms known as specific spoilage organisms (SSO) that have been associated with spoilage in most foods produced today. Preservation of meat by vacuum-packaging does not stop the spoilage process but is prolonging the shelf-life of meat by influencing both the growth rate of bacteria and the microflora's profile. Because vacuum-packaging technology does not provide a perfect anaerobiosis and, on the other hand, the partial pressure of oxygen inside of the pack depends on oxygen transmission rate of the utilised packing materials as well as vacuum level, meat is exposed to many environmental factors which are favourable for the survival and propagation of the contaminating microbial flora mainly represented by total APC, psychrophillic and lactic acid bacteria. The present study is focused on the evolution of a typical spoilage bacteria group, respectively lactic acid bacteria group, as effect of modifying plastic film's oxygen rate transmission, vacuum levels or storage temperature.