In general, it was concluded that the two common organic acids
in the food products; LA and AA, can affect the physicochemical
properties of N and CL wheat starches. Such effects were tracked
before and after gelatinization. These changes were more obvious
when LA was added. CL starch was more resistant to the changes
caused by addition of the acids. Apparently, the acids used, particularly
LA, could depolymerize some starch molecules that might be
related to the lower pH of this acid. From the DSC results, it was
found that the acids may reduce the degree of crystallinity of the
starch. The structural changes of the starch molecules caused by
the acids are important since they are probably the reasons for
the physicochemical changes of the starches treated by the acids
including interactions with water, thermal and gelling properties.
Nevertheless, further investigations are required to show exactly
how these acids can affect the molecular structure of the starches.
Based on the results, starches became more susceptible to the acids
after gelatinization. Therefore, cooked starchy foods may be more
prone to the effects of LA and AA than uncooked samples.