As acidic compounds, organic acids are characteristic components of a large number of natural substances.

An important group are the fruit acids, often hydroxycarboxylic acids such as citric acid or tartaric acid. They are not only used in the food industry, but also in many technical areas, e.g. for gentle pickling and surface treatment of metals, especially stainless steel, copper and brass items, but also in such different applications as smoothing silk or the setting of gypsum.

Due to their special properties, there are also a variety of possible applications in pharmacy and cosmetics, often as a natural preservative.

Due to their lime-dissolving properties, these acids have long been used in cleaning agents. In the food industry, citric acid and tartaric acid are used for natural acidity regulation and also for preserving food. For example, citric acid is permitted in the EU as a food additive under E 330 and natural L(+)-tartaric acid under E 334.