BEHAVIOR OF 2-O-ALPHA-D-GLUCOPYRANOSYL-L-ASCORBIC ACID IN A FLOUR-WATER SUSPENSION AND ITS EFFECTIVENESS AS A DOUGH IMPROVER

The behavior of 2-O-alpha-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 t hat of rice alpha-glucosidase. However, the hydrolysis of AA-2G was in hibited completely by endogenous sugars, mainly maltose, which were pr oduced rapidly during the hydration of flours. In the presence of Sacc haromyces cerevisiae strain with a strong maltose-utilizing capability , the hydrolysis of AA-2G proceeded in a flour suspension, and was fol lowed by the formation of dehydro-L-ascorbic acid. The hydrolysis of A A-2G also proceeded in yeasted dough, concomitant with increases in th e resistance on an extensigram and in the loaf volume of the bread. Th ese effects of AA-2G on dough were less than those of equimolar AA bec ause of the imperfect liberation of AA. The results show that AA-2G co uld be useful as a highly stable dough improver.