Bacterial Spores and Food Safety

Bacterial spores when present in processed foods can germinate under favorable conditions and cause either food spoilage or food borne illnesses when the food is consumed. E.g. the spores of Clostridium botulinum present in low acid canned foods. The use of high temperature processing in combination with anaerobic storage conditions is usually sufficient to eliminate bacterial spores based on their D-values. However, if marginal heating is done (sub-lethal heat processing) due to compromises for nutritional or organoleptic quality, the spores may survive and subsequently germinate, causing a food safety problem. Although GMP of thermally processed foods requires that enough heating be applied to eliminate microbial vegetative organisms and spores, sometimes residual bacterial spores, especially the spores of thermophillic organisms may still be present following the heating process of canned foods. However these thermophillic spores may pose no food safety problem due to the fact that the cans are cooled down quickly following the heating process and then stored at room temperature conditions, which inhibit the germination, and subsequent proliferation of the spores. In dried/powdered foods that are to be reconstituted before consumption, bacterial spores, if present, can become a food safety problem and can lead to spoilage of the improperly stored reconstituted food or lead to intoxication of consumers when the food is ingested.
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Effect of Thermal Modification and Lipid Oxidation on Traditional Food Flavors

Thermal modification of foods involves heating foods to optimum temperatures so as to achieve desirable changes in the quality and flavor of the food. Thermal modification contributes to the flavor of traditional foods by inducing both desirable and undesirable flavors in the food which are responsible for the distinctive character of the food. The action of heat (cooking, frying, steaming, roasting, grilling, etc) contribute to the characteristic flavor of traditional foods by release of volatiles, induction of maillard reaction, condensation, polymerization, and degradation of organic and chemical compounds. The degree and manner to which foods are thermally modified determine the type of flavors produced, which also characterizes the distinctive flavor attributes of the food.
Lipid oxidation is the addition of oxygen molecules unto unsaturated fatty acids leading to the formation of peroxides, which are then degraded to form secondary oxidation products e.g. aldehydes, ketones, and hydrocarbons. Lipid oxidation can also contribute some desirable flavor attributes that are characteristic of processed foods.