Chemistry is an integral part of our meals with a large number of chemical substances commonly added to foods to help their preservation or improve their taste. Since ancient times, additives such as salt, spices or sulfites have been used to preserve foods and make them more palatable. But the increased processing of foods in the 20th century created the need for new types of additives and their greater use.
For example, many of the lemon, lime or citrus soft drinks available today use citric acid as a way of enhancing the flavour. Food emulsifiers are chemical additives that encourage the suspension of one liquid in another, as in margarine, ice cream or salad dressing. Contrary to what one might think, gelatin is not an additive but a food product in its own right – a highly digestible animal protein and a pure food protein of natural origin which is added to other foods, not only for technological reasons but because it increases the protein content.
Many of our foods are in direct contact with plastics, papers, boards, metals or coatings. This explains why chemical substances called food contact additives are added to these materials as stabilisers, processing aids or processing agents. Water, too, needs to be treated. This is done through synthetic organic ion exchangers and adsorbents.