Citric acid is a natural acid found in fruits such as lemons, limes, peaches, plums, grapefruit and oranges. Citric acid is responsible for the tart taste in many citrus fruits and can be extracted by adding calcium oxide, which forms calcium citrate. Citric acid promotes healthy digestion, may prevent urinary tract infections, and is a natural preservative. Probably the most popular acid for wine making adding a pleasant fruity flavour. Can also be used in soft drinks making and as a household descaler. The acidic pH of citric acid also makes it useful as a preservative. Since many bacteria are unable to grow in an acidic environment, citric acid is often added to jams, jellies, candy, canned foods, and even meat products as a preservative. Because citric acid can be made in a powder form, it can be used in dry foods when a sour flavour is desired. Citric acid is therefore a dry alternative to lemon juice or vinegar in dry foods such as seasoning salts, flavouring powders, and crunchy snacks.