The potential of enzyme entrapment in konjac cold-melting gel beads

Abstract

The encapsulation of proteolytic enzymes in cold-melting hydrogel has been investigated. The objective was to enhance proteolysis during cheese production by maintaining enzymes in the beads during the clotting step and by releasing them during ripening through bead liquefaction (as temperature decreases). Konjac flour, a glucomannan, forms a gel after a mild alkali treatment and heating. The gel is liquefied easily at cold temperatures (⩽10°C). A two-phase dispersion process has been adapted which allows the preparation of spherical konjac beads (50–500 μm diameter). The encapsulation yield of Protease B500 is about 50% based on residual proteolytic activity. A low leakage of enzyme at 30°C was found. This makes the system suitable for use during gel formation in cheese manufacture; however, at 4°C, the liberation of enzyme is 7% within 24 h, which is too low to ensure fast cheese ripening. Syneresis of the konjac gel beads under shear stress explains this low enzyme release. Evaluation of other gels is undertaken.