Food Spoilage and Food Contamination

Abstract

The interaction of versatile nutrients and enzymes present in food leads to several degradative chemical changes that deteriorate the quality and shelf life of food. The deteriorative changes are enhanced by contamination that occurs at various stages of processing, handling and storage. The undesirable changes include lipid oxidation, enzymatic or non-enzymatic browning, putrefaction and toxicity due to hazardous substances. Contamination occurs from various physical, chemical and biological sources and is affected by external factors such as temperature, poor hygiene and sanitation. The intrinsic factors such as pH, redox potential, water content and the presence of antimicrobial substances in food also affect the degree of contamination and thereby the spoilage. Most of the contaminants occur from natural sources but some are added as a result of human activities. Contamination leads to spoilage of food due to the microorganisms, enzymes, chemical reactions (harmful additives, mycotoxins, bacterial toxins and radiations) and physical changes (caused by freezing, burning, drying, pressure). Spoilage changes the nitrogenous organic compounds in food into alpha-keto acids, ammonia, propionic acid, amides, imides, and urea. The organic acids are oxidized to carbonates causing the medium to become more alkaline and the consumption of contaminated and spoiled food can lead to various food borne illnesses and intoxication. Therefore, it is necessary to implement and maintain proper food hygiene during processing and storage. The various techniques such as biosensors, apt sensors and spectroscopy with chemometrics analysis for the quantitative assessment of food spoilage may be incorporated. The chapter focused on different aspects of food sanitation, microbiology, contamination, personal hygiene, spoilage and the effective measures to increase the shelf-life of the food and food products.