Tofu whey permeate is an efficient source to enzymatically produce prebiotic fructooligosaccharides and novel fructosylated α-galactosides

This work addresses a novel and efficient bioconversion method for the utilization of tofu whey permeate (TWP), an important byproduct from the soybean industry, as a precursor of high value-added ingredients such as prebiotic fructooligosaccharides and novel fructosylated α-galactosides. This process is based on the high capacity of the commercial enzyme preparation Pectinex Ultra SP-L to transfructosylate the main carbohydrates present in TWP as sucrose, raffinose, and stachyose to produce up to a maximum of 164.2 g L (equivalent to 57% with respect to initial sucrose, raffinose, and stachyose contents in TWP) of fructooligosaccharides and fructosylated α-galactosides in a balanced proportion. Raffinose- and stachyose-derived oligosaccharides were formed by elongation from the nonreducing terminal fructose residue up to three fructosyl groups bound by β-(21) linkages. These results could provide new findings on the valorization and upgrading of the management of TWP and an alternative use of raw material for the production of FOS and derivatives.This work has been financed by the Ministerio de Economia y Competitividad (Projects AGL2011-27884 and AGL2014-53445-R) and by the Spanish Danone Institute.Peer Reviewe