Optimization of enzymatic process parameters for increased juice yield from carrot (Daucus carota L.) using response surface methodology.

摘要

The effects of enzyme concn. (50-650 mg/kg grated carrot), pectolytic and cellulolytic enzyme ratio (3:7-7:3), incubation time (30-150 min) and temp. (25-65degC) on recovery and viscosity of juice extracted from grated carrots were investigated. A central composite rotatable design was used in designing treatment combinations of the 4 variables at 5 levels. To prepare the juice, blanched grated carrot was incubated with mixture of crude pectolytic enzyme from Aspergillus foetidus and crude cellulolytic enzyme from Trichoderma reesi prior to extraction. Enzyme-treatment increased juice recovery. A second-order response surface model adequately fitted the data. All the variables affected juice recovery and viscosity significantly. Enzyme concn., pectolytic and cellulolytic enzyme ratio, incubation time and temp. had total and combined effects on both responses at linear, square and interactive levels. Optimum extraction conditions included: an enzyme concn. of 210.7 mg/kg grated carrot; a pectolytic and cellulolytic enzyme ratio of 3.84:6.16; an incubation time of 130 min; and an incubation temp. of 47degC. Under these conditions, the juice yield was 74.3% and its viscosity was 1.07 cP.