Characterizing NAD- and NADP-dependent Alcohol Dehydrogenase Enzymes of Strawberries
in Journal of the American Society for Horticultural ScienceThe NAD-dependent and NADP-dependent alcohol dehydrogenase activities of strawberries (Fragaria xananassa Duch.) were found to have broad substrate specificities including those alcohols and aldehydes responsible for strawberry aroma and flavor either directly or through their ester products. NAD-dependent activities were greatest against short-chained alcohols, whereas the NADP-dependent activities were most active against aromatic and terpene alcohols. Differences were seen in substrate specificity between receptacle and achene alcohol dehydrogenase activities. Alcohol dehydrogenase activities were found to be developmentally regulated in receptacle tissue and increased during the period of fruit maturation and ripening. Isoelectric focusing of NAD-dependent ADH activities showed that several isozymes of this enzyme exist, that they differ between receptacle and achene tissues, and that they vary among specific genotypes. Our results suggest that NAD- and NADP-dependent ADH activities are integral components of flavor and fragrance volatile production in ripening strawberries.
