Citric acid is one of the most common food preservatives and flavouring additives. It can be found naturally in citrus fruits but is also manufactured. Its name is derived from the fact that it's an organic acid found in many fruits and vegetables, especially citrus fruits. Citric acid is a concentrated powder that is prized for its sour flavour, preservative quality, and ability to act as a pH buffer. For these reasons, citric acid is found on the ingredients list of many foods in your kitchen pantry, including preserves.
Because citric acid kills bacteria, mold, and mildew, it's also great for general disinfecting and cleaning. It's also effective at removing soap scum, hard water stains, calcium deposits, lime, and rust. Also, it serves as a preservative in many cleaning solutions.