Final answer:
Fruit acid peel is classified as a food acid. Citrus fruits contain citric acid, while vinegars contain acetic acid. Acidic substances like fruit acids are commonly used as preservatives and for other purposes in the food industry.
Step-by-step explanation:
Fruit acid peel is classified as a food acid. Citrus fruits such as oranges and lemons contain citric acid, which is a weak acid. Vinegars, on the other hand, contain acetic acid. Acidic substances like fruit acids are commonly used as preservatives and for other purposes in the food industry.