Preservatives

Safety assessment of preservatives and food additives is based on reviews of all available toxicological data, including observations in humans and in animal models. This chapter describes the types of preservatives such as chemical preservatives added to the food, natural preservatives generated by or added to the food and gases used to modify the atmosphere above a food. The salts of organic acids are often added to low pH foods to reduce the growth of yeasts and moulds. Preservatives, such as sorbate and benzoate, are generally used for lower-pH foods because they work better in acidic environments at or near their pKa values. Extracts and essential oils from plants have been shown to inhibit the growth of a range of microorganisms. Modified atmosphere packaging (MAP) uses a combination of carbondioxide, oxygen and nitrogen to control microorganism growth and extend shelf life.