Invertase-catalyzed reactions in alcoholic solutions.

The formation of alkyl beta-D-fructofuranosides by invertase from sucrose in aqueous solutions of methanol, ethanol, or n-propanol is studied for the dependence on alcohol and invertase concentrations as well as on reaction time. The yield of alkyl beta-D-fructosides is shown to be controlled by three competitive reactions: the alcoholysis of sucrose, the hydrolysis of sucrose, and the hydrolysis of alkyl beta-D-fructosides. Both the conversion rate of sucrose and the fraction of alkyl beta-D-fructosides in the product mixture are dependent on the chain length of the alcohols. They decrease in the sequence methanol > ethanol > n-propanol. Alkyl beta-D-fructosides are also formed by invertase starting from alcoholic solutions of fructose.