Hydrolysis of Oat Starch by Amyloglucosidase and Pullulanase

Abstract

This study describes the enzymatic conversion of oat starch to maltose and glucose under laboratory conditions. First, oat starch is isolated by two different extraction methods (alkali and acid-alkali). Second, enzymatic starch hydrolysis is carried out for 10% and 12.5% starch solutions obtained by both extraction methods. Third, pullulanase usage together with amyloglucosidase is investigated during saccharification. Finally, effects of the extraction method, starch concentration, and use of pullulanase are evaluated. The use of a 12.5% starch solution obtained by the acid-alkali method results in higher rates of conversion of starch to glucose and maltose, expressing better substrate for syrup production compared to alkali starch. The use of pullulanase increases the rate of starch conversion to glucose and maltose. The highest conversion of starch to glucose is found to be 49.06% when pullulanase (12 U) is used with amyloglucosidase. The highest dextrose equivalence (DE) value is 97.71, and it is obtained by using pullulanase in 10% acid-alkali starch. The data obtained in the study show that oat starch can be a suitable source for use in sugar syrup production. The 12.5% starch concentration provides high yield, and the use of pullulanase increases both the amount of hydrolysis products and the DE value.