超声脱酯制备低甲氧基果胶

The Preparation of Low-methoxyl Pectin by Ultrasonic Method

分别采用超声波法、酸法和超声辅助酸法3种方法制备低甲氧基果胶,对比分析不同超声强度、超声时间、酸浓度及酸降解时间对低甲氧基果胶制备的影响,并利用傅里叶红外光谱和高效液相色谱对商品果胶的酯化度进行定性及定量分析,结果表明:超声波法、超声辅助酸法及酸法3种方法均可达到降解高甲氧基果胶制备低甲氧基果胶的效果。果胶甲酯化度和乙酰化度随着超声时间的增长,超声强度的增大而减小。当超声时间150 min,超声强度285 W/cm2时,制备的低甲氧基果胶的甲酯化度达到31.27,乙酰化度达到0.69;当超声时间90 min,超声强度475 W/cm2时,制备的低甲氧基果胶的甲酯化度达到32.56,乙酰化度0.67,说明超声波为一种绿色、低碳的可控制备低甲氧基果胶的方法。

From the aspect of ultrasonic intensity, ultrasonic time, acid concentration and acid degradation time, the process of ultrasound, ultrasound-assisted acid method and acid were investigated to prepare LMP, and the degree of esterification of pectin was analyzed by FTIR and HPLC. The results show that： the ultrasonic method, ultrasound-assisted acid method and the acid method can achieve the effect of HMP degradation in order to prepare LMP. The DM and DA of pectin were decreasing when ultrasound time and ultrasound intensity were increasing. When the ultrasonic time was 150 min and ultrasound intensity was 285 W/cm2, the DM of LMP reaches 31.27 and the DA of LMP reaches 0.69;ultrasonic time was 90 min and ultrasonic intensity was 475 W/cm2, the DM of LMP reaches 32.56 and the DA of LMP reaches 0.67. Ultrasound provides a green, low-carbon method of controllable preparation for low-methoxyl pectin.