Certified Cheese Professional Practice Exam

What chemical process does fermentation primarily involve?

1. Conversion of sugars to alcohol

2. Conversion of lactose to lactic acid

3. Production of carbon dioxide from glucose

4. Hydrolysis of proteins in milk

The correct answer is: Conversion of lactose to lactic acid

Fermentation primarily involves the conversion of lactose to lactic acid. This process is particularly relevant in the production of dairy products, such as yogurt and certain cheeses, where lactose, the sugar found in milk, is broken down by bacteria into lactic acid. This acidification is essential for developing the flavors and textures associated with fermented dairy products. It also plays a crucial role in preserving the product, as the lower pH inhibits the growth of spoilage and pathogenic bacteria. While the conversion of sugars to alcohol is an aspect of fermentation in processes like winemaking and brewing, it is not the primary focus in the context of cheese production. Similarly, the production of carbon dioxide from glucose is important in processes like bread-making and some beer fermentation, but it does not specifically relate to cheese. The hydrolysis of proteins in milk is important for texture and flavor development in cheese, but it is not the main chemical process involved in fermentation. Hence, the conversion of lactose to lactic acid is central to the fermentation necessary for producing many cheese varieties.