| The ultrasound-assisted enzymatic synthesis conditions of konjac glucomannan oleate were studied. With esterification rate as evaluation index, the effects of ultrasonic frequency, ultrasonic power, reaction temperature, reaction time, medium initial water activity and concentration ratio of enzyme to konjac glucomannan on ultrasound-assisted enzymatic synthesis of konjac glucomannan oleate were investigated. Then the synthesis conditions were optimized by L18(37) orthogonal experiment. The results showed that the optimal conditions were obtained as follows: ultrasonic frequency 20 kHz, ultrasonic power 220 W, reaction temperature 50?℃, reaction time 8 h, medium initial water activity 0.65 and concentration ratio of enzyme to konjac glucomannan 1∶?1.Under the optimal conditions, the esterification rate reached 83.40%, much higher than 9.48% of enzymatic process without ultrasound- assist at reaction time 8 h, so the effect of ultrasound on esterification was remarkable. |
