Acidity regulators is substances being used to maintain or chang the pH of food .

It is mainly useful to control acidifier the food needed , alkali agent and a buffer salt. With many of the features,acidifier improves food quality , such as changing the acidity of foods and maintaining and improving their flavor; enhancing antioxidant to prevent rancidity of food; and complexating with heavy metal ion to block oxidation or fading reaction, stable color, reduce the turbidity, enhanced gelling properties and so on.

Acid has a certain anti-microbial effects. using alone with acid to bacteria, we need too much for the concentration of anti-corrosion ,and it will affect the sensory characteristics of food,so it is difficult in practical applications.However, when in sufficient concentration, selecting a certain acidifier with other preservation methods, such as refrigeration, heating, etc., can effectively extend the shelf life of food. As for the choice of different acids, depends on the nature of the acid and its costs.

China has given approval license to: citric acid, lactic acid, tartaric acid, malic acid, partial tartaric acid, phosphoric acid, acetic acid, hydrochloric acid, adipic acid, fumaric acid, sodium hydroxide, potassium carbonate, sodium carbonate , sodium citrate, lemon acid, potassium, sodiun sesquicarbonate dihydrate, sodium dihydrogen citrate 17.