Aqueous extracts from date by-products of the sucrose-rich variety "Deglet Nour" were used as a starting substrate to achieve the enzymatic synthesis of fructooligosaccharides (FOS) commonly used as prebiotics. A crude β-fructofuranosidase (Ffase) preparation from Aspergillus awamori NBRC4033 was immobilized on chitosan by covalent binding through glutaraldehyde linkages (Yi = 88%, Ya = 54%), and used for this purpose. The effect of water-extraction volume on the FOS synthesis by transfructosylation was studied. It was found that 150 mL/100 g of date by-products gave the best FOS concentration and productivity (123 g/L and 18.5 g/h/100 g respectively), related to an optimal sucrose conversion of 53.26%. The main FOS product was purified via a biogel-P2 gel filtration column. Its structure was determined as 1-kestose: α-D-glucopyranosyl-(1→2)-β-D-fructofuranosyl-(2→1)-β-D-fructofuranoside by combination of 1H, 13C and 2D-NMR techniques. Our results provide new insights into the enzymatic synthesis of FOS from an alternative source of sucrose, namely date by-products.
immobilization, fructooligosaccharides, β-fructofuranosidase, Aspergillus awamori, date by-products
Publication DOI: 10.1007/s12257-011-0388-9Journal NLM ID: 101263166Publisher: Seoul, Korea: Korean Society for Biotechnology and Bioengineering
Correspondence: Issam.Smaali@insat.rnu.tn
Institutions: Laboratory of Protein and Bioactive Molecules Engineering-INSAT, Centre Urbain Nord, University of Carthage, Tunis, Tunisia, Institut de chimie moléculaire, UMR 6229, CNRS-URCA, Reims, France, INRA-URCA UMR FARE 614, Reims, France
Methods: enzymatic digestion, extraction, cell growth, centrifugation
Found