ABSTRACT
Intrinsic, extrinsic, and implicit factors are involved in food quality, e.g., causing food deterioration (Nychas and Skandamis 2005). Therefore the overall effect of a combination of factors is generally much higher than the perceived effect of each individual one. The most important intrinsic parameters are water activity, acidity, redox potential, available nutrients and natural antimicrobial substances. Extrinsic parameters are related to the environment in which a food is stored, notably temperature, humidity and atmosphere composition. Physical or chemical treatments often result in changes in the characteristics of a food product determining the microbiota associated with it. Implicit factors are those physiological properties that enable particular organisms to fl ourish resulting from the interaction of the above mentioned factors, i.e., intrinsic, extrinsic. Thus, implicit parameters are the result of the development of a microorganism which may have a synergistic or antagonistic effect on the microbial activity of other microbial communities present in the food product (Huis in’t Veld 1996).
