Utah Esthetics Written State Practice Exam

What is lactic acid primarily derived from?

1. Fruits

2. Vegetables

3. Milk

4. Grains

The correct answer is: Milk

Lactic acid is primarily derived from milk, as it is a natural byproduct of the fermentation of lactose, the sugar found in milk. This process is carried out by lactic acid bacteria, which convert lactose into lactic acid, giving products like yogurt and sour milk their characteristic tangy flavor. Lactic acid plays an important role in various applications, including skincare, where it serves as an alpha hydroxy acid (AHA) known for its exfoliating properties and ability to promote skin hydration. While fruits, vegetables, and grains can contain various organic acids, they do not primarily produce lactic acid. The specific association of lactic acid with dairy makes milk the correct choice for its primary derivation.