Food preservation

Food preservation (from the Latin conservare, 'to preserve, to keep') refers to the process of treating food so that it can be kept for longer. Products treated and packaged in this way are called preserves (via conserve from Middle Latin conserva: technically 'medicine preserved with honey or sugar').

Preservation includes processes that are intended to stop or slow down the spoilage or decay of the food and its ingredients into inedible or harmful decay products. In addition, preservation may aim to stabilize and maintain nutritional value, flavor, color, and texture (structure) over the long term. However, most processes require a compromise of these objectives. In many cases, the transition between the method of preparing and preserving a food is fluid. Often it is precisely the method of preservation by which a particular food is defined as such.

The decay which preservation is intended to prevent usually occurs as a result of biochemical processes such as microbial or enzymatic activity (autolysis). The most common application is the preservation of food in the context of industrial production, storage in the home, kitchen, in the context of self-sufficiency in food, and as a preservative technique for food and similar natural objects in museums and collections. The emergence of a food industry and the production of ready-made food on a large scale was only made possible by modern preservation techniques.

Typing

A distinction is made in the preservation of foodstuffs or semi-luxury foods:

• Fully canned products with a very long shelf life of at least two years, at temperatures below 25 °C for at least 4 years,
• Three-quarter tins which can be kept for up to 12 months (at max. 15 °C),
• Semi-preserves (preserves) which can be kept below 5 °C for at least 6 months,
• Tropical preserved at temperatures above 40 °C for at least one year,
• Long-term preparations not intended for human consumption.

Principles

To prevent biological decay, there are basic principles that also occur in combination:

1. Harmful organisms are killed or inhibited in their reproduction.
2. Contact with the harmful organism is eliminated and renewed contact is prevented.
3. The harmful organism is deprived of one of the bases necessary for it.
4. One of the ingredients is added (e.g. by distillation or refining, etc.) in such a high concentration or in such a highly concentrated form that it prevents the development of harmful organisms.
5. Food additives, such as preservatives inhibit the development of harmful organisms (see also list of food additives).
6. Food's own substances such as enzymes. Proteins are changed (denatured) to stop or slow down the chemical deterioration of the product.
7. The food is protected from physical environmental influences or is processed in such a way that it can retain its original properties for longer.