An organic compound with acidic properties is known as organic acid as the most common ones organic acids are carboxylic acids as in the biological system organic compounds contain only groups and generally are not referred to as organic acids. Various types of organic acids which are seen and used daily are lactic acid, acetic acid, formic acid, citric acid and oxalic acid. This organic acid is considered to be weak acid as it does not dissociate with the water completely and other organic acids are very much soluble in organic solvents. The conjugate bases of organic acids are citrate and lactate which are derived from citric and lactic acid. Human blood and urine thus contain this organic acid as well as degradation of products like amino acids and intestinal bacterial action on food components.
Organic acids are largely used in food preservatives because of their effects on bacteria as non- iodized organic acid penetrates the bacteria cell wall and could also disrupt the normal psychology of certain types of bacteria's. In biological terms organic acid are those acids which result in the synthetic activities of plants and animals in the form of uric acid which is termed as distinct from decomposition acids. Also these organic acids are found in all types of fruits and vegetables as these have a very pleasing flavor and also are relished by everyone. Citric acid one of the types of organic acid is very much found in fruits like oranges, lemon, lime, tangerine, tomatoes and cranberries etc. Another type of organic acid is called as oxalic acid which is found in both fruits as well as in vegetables. Especially food items like cocoa, coffee, chocolate and tea are known to be a rich source of it.
Acetic acid is very commonly found in plants as it contains sodium, potassium, ammonium and other alkalies which form salts and is found in juices of many vegetables. The other type includes tartaric acid which is found in grapes, mangoes and tamarind as this acid is converted into sugar and starches. Another one is the lactic acid which is produced by the fermentation of milk which contains sugar commonly known as lactose especially when the milk is sour. Another type includes mallic acid which is found in apples, cherries, apricots, peaches, pears and plums as these are in the combination with alkaline base.