Extraction and physicochemical properties of pectin from Premna microphylla Turcz leaves

This paper was to explore the content and quality of pectin from Premna microphylla Turcz leaves in October,optimize the pectin extraction process and enhance the utilization efficiency of it. Firstly,single factor experiments were used to compare the effect of acid extraction method and the ultrasonic assisted extraction on the extraction rate of pectin.Then,according to the Box-Behnken design principle,the extracting process conditions of pectin through the acid extraction method were optimized by Response Surface Methodology( RSM). Finally,the pectins from the two methods were separated before the physicochemical properties of them were compared.The results showed that the acid extraction method was better and the optimum conditions of the acid extraction method were the solid- liquid ratio of 1∶ 30,the extraction temperature of 88 ℃,the extraction time of 2.2 h,and the p H solution of 1.6. Under above combined condition,the extraction rate of pectin was 10.57%. Ultraviolet and Infrared Spectroscopy indicated that the structures of pectin were similar to that pectin from the orange peel. The total galacturonic acid content of pectin obtained by acid extraction method was higher than that of the ultrasonic assisted extraction method. The value of p H and the degree of esterification of pectin from two methods were similar to that of the pectin from orange peel.The ash content and calcium content were higher than that of orange peel pectin.All the indicators of the pectin products meet industry standard requirements.