What is the scientific basis for adding yeast to the dough in the preparation of bread?

The correct option is

To generate carbon dioxide for rising

Explanation

The preparation of bread relies on the metabolic activity of yeast, specifically Saccharomyces cerevisiae (commonly known as Baker’s Yeast). This microorganism utilizes fermentable sugars in the flour to perform alcoholic fermentation.

Scientific Basis

When yeast is mixed into the dough, it breaks down carbohydrates through anaerobic respiration. This biochemical process yields two primary by-products:

• Carbon Dioxide (CO₂): The gas is released in the form of bubbles, which get trapped within the gluten network of the dough. The accumulation of this gas causes the dough to expand in volume, a process known as leavening or "rising."
• Ethanol: A small amount of alcohol is produced, which evaporates during the baking process.

The porous and soft texture of bread is a direct result of the CO₂ bubbles expanding further when subjected to heat during baking. Therefore, the primary function of yeast is to generate carbon dioxide for rising, not to act as a preservative or antibacterial agent.

Key Takeaway

Baker’s Yeast serves as a bio-leavening agent in bread making by producing carbon dioxide through fermentation, which is responsible for the rising and porous texture of the dough.