Predictive Microbiology and Role in Food Safety Systems

Abstract

Food preservation has always been a challenge for humankind. The possibility of storing foods for long periods contributed to the development of abilities that have facilitated the evolution of humans. In the beginning, the main concern was eating, and the procedures used for preservation of foods (e.g., fermentation, freezing, and drying) were relatively safe, considering the possibility of developing pathogenic microorganisms. These procedures essentially stopped or impeded the growth of microorganisms, except in the case of fermentation, where some desirable microorganisms could control the development of other microorganisms, including pathogens. The concept of food safety is associated with the preservation of food by heat. In these processes, the goal is to eliminate pathogenic microorganisms and to reduce spoilage microorganisms to an acceptable level. With the development of minimally processed foods, however, this concept acquires its maximum dimension. The traditional concept of food safety cannot be extrapolated to minimally processed foods. The preservation methods used for minimally processed foods are not directly focused on the total inactivation of the microbial population present in raw materials. These foods are defined as products that receive a nonsevere thermal process (up to 100jC) and are distributed and stored under refrigeration. This conservation procedure has propitiated the growth of some foodborne emerging pathogenic microorganisms (nonproteolytic Clostridium botulinum, Bacillus cereus, and Listeria monocytogenes, among others) at refrigeration temperatures. It is obvious that the microbiological safety of food during its shelf life relies mainly on the appropriate refrigeration procedures designed to prevent the growth or toxin production of microorganisms dangerous to consumer health. The consequence is that food safety is determined by the presence and growth of pathogenic microorganisms or their toxins during refrigeration storage. The presence