Importance of Starch Damage in Wheat and Milling Industry
Importance of Starch Damage in
Wheat and Milling Industry
By, Rabia Tiryaki, MSc,
Bastak İnstruments , Turkey
Wheat, which is the
most consumed nutrient among cereal products, has maintained its indispensable
place and importance in human nutrition as a strategic product throughout the
ages. Grain products, one of the indispensable basic needs of people living in
all developed and developing countries, meet a large part of the daily energy
required by the human body. In addition, wheat and flour production activities
have once again revealed the economic value of the flour industry and the need
of countries in terms of food security, shown with the food crisis that started
in 2007 and the global economic crisis that started and continued in 2008.
At the beginning of the
chemical and physicochemical properties sought in wheat and flour or semolina
produced from wheat, the agricultural products that were the subject of the
most international trade in history; amounts of water, ash, protein, gluten,
gluten index, Zeleny sedimentation, starch and starch damage.
The amount of starch,
which is the main component in wheat flour at the highest rate, has a very
important effect on bakery products. Starch interacts with the other components
and forms the dough structure. Water absorption, one of the most important
functional parameters of starch, affects the quality and texture of bakery
products. While intact starch granules have the ability to absorb approximately
0.33 times their weight in water, damaged starch granules can absorb water as
much as their own weight.
Starch grains are found
in a regular and organize structure between protein networks in the endosperm.
However, they completely or partially lose their structure during the milling
of wheat. The resulting flour contains damaged starch and undamaged starch
granules in varying proportions. The the ratio and texture will vary depending
on the grinding system and the adjustment of the rollers-,
The amount of starch
damage has become an important quality parameter of interest to all sectors
based on grain production, especially in recent years. After the inevitable
effect of starch damage on the final product was revealed, it has become a
routine analysis in many bread production industries and grain quality control
In order to obtain
dough of suitable consistency, the absorption of flours containing excessively
damaged starch should be reduced. Excess
starch damage reduces the bread volume, affects the quality of the bread by
spoiling the crumb properties. For a good bread making, the flour to be used
must contain a certain level of damaged starch.
When there is not enough gluten to cover the large amount of surface
area that occurs, an excessive increase in this ratio reduces its ability to
hold gas and adversely affects the fermentation process.
The amount of damaged
starch has an important place in the quality parameters for the pasta industry.
During pasta making, damaged starch forms a substrate for amylase. They
increase the amount of substance that passes into the cooking water by breaking
down and cause turbidity. Semolina, which is a grinding product with low starch
damage, is preferred in the pasta industry.
For the biscuit
industry; Soft grain structure, lower protein and higher starch ratio form the
appropriate quality feature. The amount of starch damage affects the cracking
rate of biscuits. The amount of damaged starch is directly related to the
enzyme activity. Alpha and beta amylase enzymes in wheat can only break down
damaged starch. Considering that different products are obtained by using
different properties of wheat fractions in different ways, it is essential to
determine the optimum damaged starch property in order to produce the product
under optimum conditions.