低酯果胶的流变学性能研究

    Rheological properties of low methoxyl pectin

    • 摘要: 以商品低酯果胶为研究对象,以AR-500型动态流变仪为主要设备,考察低酯果胶溶液的流变学基本特性,以及温度、剪切速率、体系pH值、金属离子、糖等因素对其流体性能的影响。结果表明,低酯果胶溶液是典型的剪切稀化型非牛顿流体,果胶浓度越高,溶液剪切稀化现象越严重。同时其溶液流体行为受温度、剪切速率、pH值等因素的影响。体系温度和pH值的升高均可导致溶液黏度降低;剪切速率的影响与果胶浓度有关,在低浓度条件下(0.3%),低速率时(0~200 s-1)剪切稀化现象越严重,高速率(400~700 s-1)时转变为胀塑性流体;在高浓度(1%、2%)条件下,随着剪切速率增高,溶液流体逐渐趋向于理想状态的牛顿流体。金属二价离子对低酯果胶溶液有显著的增稠效应,其增稠效果与离子浓度呈正相关。

       

      Abstract: The fundamental rheological properties of low methoxyl pectin(LMP) and the effects of factors, such as temperature, shear rate, pH value, metal ions, sugar on rheological properties were researched with AR-500-type rheometers. Results indicate that LMP solution has typical shear-thinning property, and the rheological properties are influenced by temperature, shear rate, pH value, et al. The increasing of temperature and pH value can reduce the viscosity of LMP. The effect of shear rate is relation to the concentration of LMP. At the low concentration(0.3%), shear-thinning property of LMP will be more notability in the low shear rate(0~200 s-1) and the rheological behavior will be change to shear-thick property in high shear rate(400~700 s-1). At the high concentration(1%, 2%), the LMP will change to Newton liquid gradually with the increasing of shear rate. Metal ions obviously improve the viscosity of LMP solution, and the ability is correlated to the concentration of metal ions.

       

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