Natural Systems for Preventing Contamination and Growth of Microorganisms in Foods

Food-borne illness is a vast and costly worldwide problem. Although complex, it may be divided into two major types of animal and human disease: intoxication caused by toxic substances in food and secondly, infection, caused by microorganisms. Toxic substances may be already present in foods, or they may be produced by microorganisms through contamination and proliferation in food. Prevention of the invasion of foods by microorganisms may be achieved by effective use of intrinsic factors found in plants and animals. These factors include pH, moisture content, oxidationreduction potential, nutrient content, biological structures, and antimicrobial constituents. A second type of natural protection is that of microbial antagonism. Research work discussed includes that done in the author\u27s laboratories involving tannic acid and microbial antagonism against Listeria monocytogenes in milk. The safety of all natural mechanisms of defense is important economically and in public health. We predict that the use of antimicrobials occurring naturally in foods and safe microbial antagonism will receive more attention in future food safety research