Food Spoilage: Microorganisms and their prevention

Food spoilage can be defined as “any sensory change (tactile, visual, olfactory or flavour)” which the consumer considers to be unacceptable. Spoilage may occur at any stage along food chain. Spoilage may arise from insect damage, physical damage, indigenous enzyme activity in the animal or plant tissue or by microbial infections. Most natural foods have a limited life. Perishable foods such as fish, meat and bread have a short life span. Other food can be kept for a considerably longer time but decomposes eventually. Enzymes can bring about destruction of polymers in some foods while chemical reactions such as oxidation and rancidity decompose others but the main single cause of food spoilage is invasion by microorganisms such as moulds, yeast and bacteria. In case of mould spoilage a furry growth covers the food and it becomes soft and often smells bad. Bacterial contamination is more dangerous because very often food does not look bad even though severely infected, it may appear quite normal. The presence of highly dangerous toxins and bacterial spores is often not detected until after an outbreak of food poisoning, laboratory examination uncovers the infecting agent.