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Give us day by day our daily bread ? this is the Christian prayer for basic
food. For some it would be a Godsend to be able to incorporate the starch
qualities from wheat into other plants so that they could also be used to
produce starch, June 2005 by Flora Mauch, Checkbiotech.

Bread consists of starch, a complex carbohydrate made up of many glucose
molecules linked together and also found in other foods such as potatoes,
rice, and corn.

Yet, starch is not limited to food. It is also used to produce products,
such as paper, glue, textiles and building materials. This is due to starch?
s sticky property that enables it to give the end product the desired
texture.

In order to make starch, plants collect energy from the sun in a process
called photosynthesis. Many plants store the energy produced during
photosynthesis process in the form of glucose, which in turn is stockpiled
to starch. This carbohydrate consists of two forms of glucose units, amylose
and amylopectin, differing in their glucose linkage.

The properties of starch, which are important in food production and for
industrial uses, vary with the relative accumulation of these two major
components. Cooking and textural characteristics depend not only on the
ratio of amylopectin to amylose, but also on the degree of amylopectin
branching. In general one can say that the higher the branching of
amylopectin, the more favorable it is for industrial uses.

Modifying this parameters is not a new idea. Usually, it has been
accomplished using chemical or physical methods. Of late, biotechnological
alternatives are found in the use of enzymes.

The latest example is created by the team of Dr. Baek Hie Nahm from the
Department of Bioscience and Bioinformatics of the Myongji University.
Having known which gene led to the production of an enzyme responsible for
processing amylopectin branching, Dr. Nahm transfer the same gene into rice
plants.

As a result, they obtained transgenic rice with an increased degree of
amylopectin branching. In this way, starch is already being modified while
the rice is sprouting, what biologists call an in vivo modification. Thus,
at the time of harvest, the starch features all the properties important for
the industrial uses.

Letting the genetically modified plant carry out the starch-modifying
process, eliminates the chemical or physical treatment that is presently
required. This facilitates the convenience of a fast and efficient starch
production at a more economical and environmentally friendly price.

In vivo modification of starches using genetic engineering holds potential
for both enhancing nutritional qualities and for obviating post-harvest
modifications.

Dr. Baek Hie Nahm delineates the present situation, ?Further studies are
required to examine if this modified starch exhibits properties that are
desirable for human consumption. Current and further research will bring to
light a more complete picture of the complex and intriguing mechanism of
starch synthesis.?

[www.checkbiotech.org];
subtopic_id=1&doc_id=10472

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