Optimization of enzymatic production of prebiotic galacto/galacto(arabino)-oligosaccharides and oligomers from potato rhamnogalacturonan I.

A bi-enzymatic system using two multi-enzymatic preparations (Depol 670L and Gamanase 1.5L) was investigated for the production of prebiotic galacto/galacto(arabino)-oligosaccharides and oligomers with well-defined degree of polymerisation (DP) from potato galactan-rich rhamnogalacturonan I. Depending on the reaction condition, yields of low (DP of 2-6) and high-MW oligosaccharides (DP of 7-12) and oligomers (DP of 13-70) varied between 0.1-13.9, 0.0-37.5 and 0.0-75.7%, respectively. Substrate concentration and Depol 670L/Gamanase 1.5L ratio were identified as the most significant linear terms in oligosaccharide and oligomer yield models, respectively. Moreover, interaction between reaction time and substrate concentration had a significant effect on the yield of oligosaccharides, while interaction between reaction time and Depol 670L/Gamanase 1.5L ratio affected significantly the yield of oligomers. Higher yields of both oligosaccharides and oligomers were obtained when equal amount of Depol 670L and Gamanase 1.5L was used in combination. The DP and the monosaccharide composition of the generated galacto/galacto(arabino)-oligosaccharides and oligomers were confirmed.