微波辅助提取葡萄皮中花色苷的动力学和热力学特性

为拓展微波辅助提取技术在食品工业领域的应用，研究了微波辅助技术对提取葡萄皮中花色苷的作用，并对其动力学和热力学进行了评价。结果表明：柠檬酸浓度、液料比、提取时间和微波功率可以显著影响总花色苷提取率。采用高浓度柠檬酸水溶液（1.00?mol/L）提取的总花色苷含量（172.99?mg/100?g）是低浓度柠檬酸水溶液（0.02?mol/L）提取的总花色苷含量（43.48?mg/100?g）的4倍。此外，在实验选取的动力学模型中，指数衰减模型可以更好的拟合提取动力学数据（R2＞0.9875）。微波辅助提取葡萄皮中花色苷的有效扩散系数（2.12～4.87×10-11?m2/s）随着微波功率的增加而增大。微波辅助提取过程的热力学参数表明微波提取方式有利于传质过程。所得研究结果将为微波辅助提取技术的工业化应用提供理论依据。

Kinetics and thermodynamics characteristics of microwave assisted extraction of anthocyanins from grape peel

In order to expand the application of microwave assisted extraction (MAE) in food industry, the effects of MAE of anthocyanins from grape peel was investigated, and the related kinetics and thermodynamics were evaluated. The results showed that the citric acid concentration, liquid-to-solid ratio (RL/S), extraction time and microwave power level have a significant influence on the anthocyanins yield. The anthocyanins yield (172.99 mg/100 g) with the higher concentration of citric acid solution (1.00 mol/L) is 4 times larger than that (43.48 mg/100 g) in the lower concentration solution (0.02 mol/L). Furthermore, the extraction kinetic analysis indicated that the exponential decay model is the best model to fit the experimental data of anthocyanins obtained from MAE in this study (R2>0.9875). The effective diffusivity value of anthocyanins (2.12~4.87×10-11 m2/s) was enhanced concomitantly with increasing values of microwave power level in MAE process. The thermodynamic parameters of MAE indicated that microwave irradiation benefit the mass transfer. The result can provide a reference for industrial production of MAE.