氢氧化钠-盐酸改性处理后的余甘果粉末对EGCG的吸附作用研究

Effects of pretreatment of Phyllanthus emblica fruit powder using Sodium hydroxide-hydrochloric acid on adsorption of EGCG

本研究以氢氧化钠-盐酸改性处理后的余甘果粉末为吸附剂,对表没食子儿茶素没食子酸酯(EGCG)进行批量吸附研究。研究结果表明,改性处理的余甘果粉末对EGCG的吸附符合拟二级动力学模型;当EGCG溶液初始浓度为25～800 mg/L、吸附温度25～55℃时,改性余甘果粉末对EGCG的吸附行为可用Langmuir和Freundlich等温吸附方程进行描述;在该条件下,吸附反应的标准吉布斯自由能变为-21. 20～-24. 11 k J/mol,表明吸附反应可自发进行,并以物理吸附为主导。可见,余甘果可以作为EGCG类功能性食品的候选载体。

The NaOH-HCl pretreated Phyllanthus emblica fruit powder samples were prepared and then were used as absorbent for isolating Epigallocatechin gallate(EGCG)in this study.The adsorption behaviors of EGCG onto emblica fruit powder in aqueous solution were studied at a concentrations range of 50-800 mg/L and temperature range of 25,40 and 55 C.The results showed that both of the Langmuir and Freundlich models adequately described the isothermal adsorption process,with an excellent fitness to the pseudo-second-order adsorption kinetics model.Thermodynamics analysis suggested that the adsorption process was endothermic and spontaneous,suggesting that the emblica fruit powder has the potential for using as a food matrix for delivering EGCG in food nutrition applications.