Citric acid is a naturally occurring chemical substance found in lemons and citrus fruit as well as in strawberries, pineapple, and kiwi in smaller quantities.
It’s used in food processingas a natural preservative and thickening agent as well as to regulate acidity.
In cooking it’s used to thicken jams. It’s also used as a tenderizer in marinades while it’s also added to fruit salads to prevent fruit discoloration.
Citric acid prevents the formation of sugar crystals in homemade marmelades and caramel. It can be used as a substitute for lemon.