Enzymatic solubilization of arabinoxylans from isolated rye pentosans and rye flour by different endo-xylanases and other hydrolyzing enzymes. Effect of a fungal laccase on the flour extracts oxidative gelation

Figueroa-Espinoza Maria-Cruz, Poulsen Charlotte, Borch Soe Jorn, Zargahi Masoud Rajabi, Rouau Xavier. 2002. Enzymatic solubilization of arabinoxylans from isolated rye pentosans and rye flour by different endo-xylanases and other hydrolyzing enzymes. Effect of a fungal laccase on the flour extracts oxidative gelation. Journal of Agricultural and Food Chemistry, 50 (22) : 6473-6484.

Résumé : Water-extractable (WEP) and water-unextractable (WUP) pentosans were isolated from a rye flour. The effect of a commercial enzyme preparation, Grindamyl S 100 (GS100), containing pentosanase activities, was investigated on WEP, WUP, a mix of WEP and WUP, and the rye flour, with the aim to monitor the solubilization and depolymerization of high molecular weight arabinoxylans and the effect on the viscosity of the reaction medium. The effects of other hydrolyzing enzymes were also tested. Three xylanases were used: xylanase 1 (Xyl-1) from Aspergillus niger, the main activity present in GS100; xylanase 2 (Xyl-2) from Talaromyces emersonii; and xylanase 3 (Xyl-3) from Bacillus subtilis. Xyl-3 was used in combination with Xyl-1, (1,4)-bêta-D-arabinoxylan arabinofuranohydrolase, endo-bêta-D-glucanase, or ferulate esterase from A. niger, but no synergism was observed. GS100 and xylanases increased the arabinoxylan solubilization, Xyl-3 and Xyl-1 being those that presented the best yields of extraction without extensive depolymerization of water-extractable arabinoxylans. Both xylanases were affected by an inhibitor in rye flour. Flour treated with hot ethanol was used to study the oxidative gelation of flour extracts treated with xylanases, in the presence of laccase from Pycnoporus cinnabarinus. Two doses of xylanases were tested (0.5 and 2.5 units). Only the flour extracts treated with 0.5 unit of Xyl-1 thickened.

Mots-clés Agrovoc : seigle, pain, pentosane, xylane, activité enzymatique, laccase, solubilisation, gélification, farine de seigle, glucane, estérase

Classification Agris : Q02 - Traitement et conservation des produits alimentaires

Auteurs et affiliations

• Figueroa-Espinoza Maria-Cruz, INRA (FRA)
• Poulsen Charlotte, Danisco Cultor (DNK)
• Borch Soe Jorn, Danisco Cultor (DNK)
• Zargahi Masoud Rajabi, Danisco Cultor (DNK)
• Rouau Xavier, INRA (FRA)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/519304/)

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