Biotechnology in food processing

Biotechnology has been broadly defined as the utilization of biologically derived molecules, structures, cells or organisms to carry out a specific process. This is true of many established food processes – for example, cheesemaking and brewing.

The beauty of modern biotechnology lies in the specificity. The biotechnologist can target only one or two protein molecules for change in an organism containing thousands of proteins.

The seemingly minor alterations can have profound effects. The amount of an important flavor, color or enzyme may be increased many fold. It can allow crops to grow under marginal to poor conditions.

With a few exceptions, most short-term results of modern biotechnical applied to food production will be invisible to the consumer’s eye.

However, indirect effects on existing product, such as cost savings and product improvements, will be far reaching.

It is therefore important for the public to be informed of the benefits that the biotechnological revolution can provide.
Biotechnology in food processing

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Technology of bread baking

The function of baking is to present cereal flours in an attractive, palatable and digestible form.

Most bakery products are made of the same few ingredients – flour, shortening, sugar, eggs, water or milk and leavenings.

The dough is kneaded by hand or machine. After the dough rests for some time (about 2 hours) it is manipulated to push out the gas that has been evolved.

Three process are commence when the ingredients for bread making are mixed.
*The protein in the flour begin to hydrate and to combine with some water , to form gluten.
*Air bubbles are folded into dough. During the subsequent handling of the dough these bubbles divide or coalesce.
*Enzyme in the yeast start to ferment the sugars present in the flour and later sugar released by diastatic action of the amylases on damaged starch in the flour, breaking them down to alcohol and carbon dioxide.

The dough is then moulded into loaf shape and allowed to rest in the baking pan for 45 to 60 minutes at 38° – 48° C for final proof and is then baked for about 30 minutes with steam injected into the oven to produce a glaze on the crust.

Loaf sized are breads is baked in an oven pre-heated to 204° C. After the first 15 minutes of baking, the temperature is reduced if the crusts become to brown. Baking is continued until the bread is fully baked.

There are four major changes to the dough piece which can be seen as it is baked:
*A large reduction in product density – the dough gets thicker, associated with development of an open porous or flaky structure
*A change of shape associated with shrinkage or spread and increase on thickness
*A reduction in moisture level, to between 1-4%
*A change in surface coloration
Technology of bread baking

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