Production of fructooligosaccharides by high pressure-treated crude inulinase enzymes

We examined effects of high pressure treatment on a crude inulinase enzymes preparation to prepare fructooligosaccharides (FOS) by using fructosyltran sferring activity in it. By a treatment, of the crude enzyme solution at 70 0 MPa for 60 min at pH 5.0, activities degrading inulin, nystose and 1-kest ose decreased to 0.9%, 2.5% and 14.7% of its original activities, respectiv ely. But sucrose degrading activity still remained up to 51.2%, suggesting that an exo-type inulinase was almost inactivated, while beta-fructofuranos idase activity was survived relatively. Fructooligosaccharides actually for med were broken down into glucose and fructose almost completely, when the non-treated crude enzyme solution was used for the reaction with 16% or 48% (w/v) sucrose at pH 5.0 and 50 degrees C for 24 hours. Contrary to this, f ructooligosaccharides were not degraded and remained, when the crude enzyme solution treated by high pressure at 700 MPa for 60 min was applied under the same conditions. It was suggested that these results were attributable to the inactivation of exo-type inulinase under high pressure.