Citric acid is primarily found in citrus fruits, especially lemons and limes. The amount of acidity can be estimated by a fruit's taste, so fruits with high amounts of citric acid taste more sour. Citric acid is also found in most berries, including cranberries, black currants, red currants, raspberries and strawberries.
Vegetables, such as cayenne peppers and artichokes, also contain citrus acid. Tomatoes, which technically are fruits, contain the acid as well.
Citric acid is used in food and beverage processing too. Processed foods and drinks that contain the substance include soda, preserves, sourdough bread, wine, mayonnaise and even some ice creams. Citric acid is used as an emulsifier in ice creams that contain vegetable fat. The acid is also the main ingredient in frozen fruit treats, such as sherbet.
In the beauty and cosmetic industry, citric acid is included in various skin care preparations and soaps. The acid is used to adjust the pH levels in the products and provide antioxidant protection and skin exfoliation for the user.
Excessive consumption of citric acid can result in nausea, diarrhea and vomiting. The ingredient, when added to a lotion or cream, may cause dermatitis to develop in people with sensitive skin.