Medium engineering of phenylethanoid transfructosylation catalysed by yeast β-fructofuranosidase

Tyrosol and hydroxytyrosol, by-products of olive oil production, are valuable substrates for enzymatic transglycosylation that can provide products with pharmaceutical potential. Phenylethanoid fructosides are produced from sucrose and phenylethanoids by the catalytic action of beta-fructofuranosidases. This work dealt with the potential of the most abundant beta-fructofuranosidase, baker's yeast invertase, for this bioconversion. The effects of sucrose and phenylethanoid concentrations were investigated with a focus on the selectivity of phenylethanoid transfructosylation and fructoside yields. For this purpose, initial rate and progress curve experiments were carried out for the initial (hydroxy)tyrosol and sucrose concentrations of 0.072-0.3 M and 1-2 M, respectively. Reaction courses exhibited either a maximum or plateau of fructoside yield in the range of about 10-18%. The addition of deep eutectic solvents was applied in the concentration range from 5 to 70% (v/v) to investigate the possibility of shifting the reaction equilibrium towards fructoside synthesis. [GRAPHICS]

Automated summary

Tyrosol and hydroxytyrosol, by-products of olive oil production, can be used as valuable substrates for enzymatic transglycosylation to produce pharmaceutical products. This study investigated the potential of baker's yeast invertase for the conversion of sucrose and phenylethanoids to phenylethanoid fructosides. The effects of sucrose and phenylethanoid concentrations on transfructosylation selectivity and fructoside yields were studied, with the addition of deep eutectic solvents to shift the reaction equilibrium towards fructoside synthesis.