Evaluation of the physicochemical and pasting properties of physically modified local maize starch

Abstract

This study was conducted at the laboratories of Food Science Department, Faculty of Agriculture, Damascus University, and the Central Grain Laboratory in order to evaluate the physicochemical and pasting properties of starch extracted from local and physically modified maize cultivars. Two cultivars of maize grown in two different regions were selected, the starch was extracted and physically modified by pre-gelatinization and milling methods, and then the physicochemical and pasting properties of the extracted starch were evaluated according to the methods approved by AACC. The results showed significant differences in the studied physicochemical and pasting indicators of the original starch extracted from the studied corn varieties, as well as between the two cultivation sites. On the other hand, the results showed that the process of pre-gellation of starch led to significant changes in the values of all physicochemical indicators, except for the moisture content, compared to the original starch, and the values of these indicators decreased significantly. In addition, the pre-gelatinization process led to a significant decrease in the studied pasting indicators. On the contrary, the process of physical modification of starch by grinding method did not cause significant differences in most of the studied

physicochemical indicators, except for the lipid content and color degree, compared to the original starch, while the most important effect was a significant decrease in pasting indicators. As a result, calculating the relative effect of the studied variables that affected the physicochemical and pasting properties of starch, according to the F-test at a confidence level of 5%, showed that the modification method was responsible for the largest percentages of variance in all these variables.