Microbial Food Spoilage: Control Strategies for Shelf Life Extension

Food spoilage can be defined as any sensory change in food flavor which the consumer considers to be unacceptable. Spoilage may arise from insect damage, physical damage (freezing, drying, etc.), chemical changes (usually involving oxygen), and indigenous enzyme activity in the animal or plant tissue. Spoilage is therefore complex and may occur at any stage along the food chain. Bacteria, fungi, yeast, and insects are the main cause for food spoilage. There are a wide range of metabolites produced during microbial spoilage including alcohols, sulfur compounds, hydrocarbons, fluorescent pigments, as well as organic acids, esters, carbonyls, and diamines. Preservation of food for its safety and long shelf life is dependent on the food type and properties (pH, water activity, nutrient content, antimicrobial constituents, etc.), initial microbial flora, and processing and storage conditions (heating, acidification, reduced water activity, storage atmosphere, chilled storage, etc.). This review deals with food spoilage, microbes causing food contamination, prevention of microbial spoilage, and preservation of foods.