Question

Bread or idli rises because of
a) Heating
b) Grinding
c) Growth of yeast cells
d) Kneading

Answer 1

Hint: Fermentation is both a natural and industrial process. Naturally, it is performed by yeast. Artificially it is done for production of different products like alcohol, bread. Bread or idli are made by the process of fermentation. Bread mainly involves use of yeast.

Complete answer:
 To answer this question, we must understand process of bread-making:
Bread making is an important occupation to mankind. The mixture of tiny creatures with wheat flour has paved a way to this amazing discovery. Bread making requires, mainly four ingredients: wheat flour, yeast, salt and water.
Method: The method bread making involves following steps:
> Sifting- Sifting of dough is the first step. It is done to remove foreign particles, aerate the mixture and make it more homogenous.
> Next step is to mix the dough properly using various methods.
> After the dough is set, it is cut into pieces which are then rounded to ball shape.
> The gluten fibers need to be given time to recover their extensibility so that they can be moulded properly without breaking surface skin. This is done by passing the pieces into intermediate proofer.
> After this, the dough is passed through a set of rollers to form a sheet.
> This sheeted dough is moulded to cylindrical shape by passing it through pressure.
> The moulded pieces are placed into tins where they are greased. This panned dough is passed to the final prover under controlled conditions.
> The dough tins are transferred to the baking oven.
> Once baking is completed, the breads are de-panned, cooled and then sliced. Sliced breads are then packaged in suitable packaging material, generally polypropylene pouches.

Thus, the correct answer is option C- Growth of yeast cells.

Note: The principle behind this method:
As the yeast consumes, wheat starch is partly converted to sugar. This process is called fermentation. Carbon-dioxide is released in this process and that leads to a porous texture of bread.
The wheat gets hydrated to form gluten. Gluten appears like silky stretched fibers. Carbon-dioxide formation leads to gluten formation. Alcohol is released in the fermentation process, this adds flavors to the bread.