MICROBIOLOGY AND THE SHELF LIFE OF REFRIGERATED PRODUCTS
shelflife of food products is most familiar to consumers through the open dating used on refrigerated goods The shelf life of these types of products is affected, for the most part, by their microbiological status. These products pose the highest food safety risk and have the shortest shelf life because they are the most susceptible to microbiological deterioration and the possibility of the growth of pathogenic organisms. Bacteria need certain conditions for growth - namely available moisture, the proper pH, the right temperature and nutrients and time. By controlling these conditions one can prevent the growth of these organisms and extend the shelf life. Once the product has been developed utilizing a combination of the proper ingredients, pH, water activity and microbiological inhibitors, its shelf life can be determined in real time at the various temperatures, which may be encountered during storage and distribution. The growth of yeasts, mold, spoilage and pathogenic bacteria, etc., can be monitored by microbiological methods. Other noticeable reactions such as gas production, syneresis (phase separation), and changes in color or viscosity can give further indications as to what might have to be changed in the formulation or packaging to increase the shelf life. Another means of ensuring the product will have an adequate shelf life is to challenge the product with inoculi of various spoilage organisms, as well as some potentially pathogenic bacteria. This step will ensure the product will be safe for the consumer as well as aesthetically pleasing at the end of its shelf life. Listeria monocytogenes grows under refrigerated conditions. It is imperative that it not be present in refrigerated products, but that it be dealt with via elimination from the plant environment to assure against its presence in the product. Microbiological shelf-life determinations can usually be accomplished in real time and are therefore, quite accurate.