水力空化对果胶粘度的影响及其凝胶色谱表征

Effect of hydrodynamic cavitation on the viscosity of pectin and characterization by gel permeation chromatography

为探明水力空化对果胶粘度及分子量分布的影响,通过空化装置产生空化效应并作用于果胶溶液,研究不同p H、温度、入口压力、初始浓度、作用时间下水力空化处理前后果胶粘度的变化,以粘度的下降率来衡量水力空化对果胶的作用效果,并采用凝胶色谱法(gel permeation chromatography,GPC)对空化处理前后的果胶分子量分布进行比较分析。结果表明,当溶液p H为5,温度为50℃,入口压力为0.1 MPa,果胶浓度为1 g/L,处理时间为60 min时,果胶粘度下降率达15.76%。经GPC分析发现,果胶相对平均分子量由70515 Da下降至57408 Da。所以用水力空化处理果胶可以有效降低果胶粘度及其分子量,为果胶降解提供了一个新方法。

In order to find out the effect of hydraulic cavitation on the viscosity and molecular weight distribution of pectin, the cavitation effect was generated by the cavitation device and acted on the pectin solution.The change of pectin viscosity before and after hydrodynamic cavitation treatment was studied under different pH, temperature, inlet pressure, initial concentration and reaction time. The effect of hydrodynamic cavitation on pectin was evaluated by the decreasing rate of viscosity. The molecular weight distribution of pectin before and after treatment was analyzed by gel permeation chromatography （GPC）.The results showed that when the pH of the solution was 5 ,the temperature was 50 ℃ ,the pressure of the population was 0.1 MPa, the concentration of pectin was 1 g/L and the treating time was 60 min, the viscosity of the pectin decreased by 15.76% .The GPC analysis showed that the relative average molecular weight of pectin decreased from 70515 to 57408.So the pectin treated by hydraulic cavitation can effectively reduce the viscosity of pectin and its molecular weight,which provided a new method for pectin degradation.