Behavior of 2-O-α-D-Glucopyranosyl-L-ascorbic Acid in a Flour-water Suspension and Its Effectiveness as a Dough Improver

Abstract

The behavior of 2-O-α-D-glucopyranosyl-L-ascorbic acid (AA-2G) in a whole wheat flour suspension was investigated. AA-2G was hydrolyzed by a non-dialyzable and heat-labile component in flour and liberated L-ascorbic acid (AA). The pH profile for the hydrolysis is similar to that of rice α-glucosidase. However, the hydrolysis of AA-2G was inhibited completely by endogenous sugars, mainly maltose, which were produced rapidly during the hydration of flours. In the presence of Saccharomyces cerevisiae strain with a strong maltose-utilizing capability, the hydrolysis of AA-2G proceeded in a flour suspension, and was followed by the formation of dehydro-L-ascorbic acid. The hydrolysis of AA-2G also proceeded in yeasted dough, concomitant with increases in the resistance on an extensigram and in the loaf volume of the bread. These effects of AA-2G on dough were less than those of equimolar AA because of the imperfect liberation of AA. The results show that AA-2G could be useful as a highly stable dough improver.