Question

All dairy fermentations use lactic acid bacteria for -

• A. Acidification and flavour production
• B. Salting
• C. Sweetening
• D. Bitterness

Hint:

The name of the bacteria itself gives away its main function: {Lactic Acid Bacteria} produce {Lactic Acid}. This acid is key to preservation, texture, and taste. Flavor compounds are the other major contribution.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
This question asks for the primary and universal function of Lactic Acid Bacteria (LAB) in the production of fermented dairy products like yogurt, cheese, and buttermilk.
Step 2: Detailed Explanation:
Lactic Acid Bacteria are the cornerstone of dairy fermentations. Their primary metabolic function is to consume lactose (milk sugar) and convert it into lactic acid. This has two major effects:
Acidification: The production of lactic acid lowers the pH of the milk. This acidity inhibits the growth of spoilage and pathogenic bacteria, thus preserving the product. It also causes the casein proteins to coagulate, forming the characteristic gel of yogurt or the curd of cheese.
Flavour production: Along with lactic acid, which provides a clean, tart taste, LAB also produce a range of other compounds like diacetyl (buttery flavor), acetaldehyde (green apple flavor in yogurt), and other esters and aldehydes. These contribute significantly to the unique aroma and flavor profile of each fermented product.
The other options are incorrect. Salting is a separate processing step, sweetening is usually done by adding sugar, and bitterness is a flavor defect, not a desired outcome.
Step 3: Final Answer:
The fundamental role of lactic acid bacteria in all dairy fermentations is acidification and flavour production.