制备西瓜皮果胶工艺条件的研究

A RESEARCH ON TECHNOLOGICAL CONDITIONS FOR WATERMELON RINDS PECTIN PREPARATION

本文研究了以西瓜皮为原料，采用稀Ｈ２ＳＯ３（其中含有少量Ｈ３ＰＯ４）溶液萃取，乙醇沉淀的方法制备西瓜皮果胶的工艺条件。探讨了萃取温度、萃取时间、萃取液ｐＨ值对果胶产率、凝胶强度的影响，获得最佳提取条件是：将一定量西瓜皮，置于ｐＨ２．８的Ｈ２ＳＯ３溶液（其中含少量Ｈ３ＰＯ４）中，加热至９５℃并恒温１２０ｍｉｎ萃取液过滤浓缩后，加入浓缩液体积１倍的９５％乙醇以沉淀果酸。以此法制得的果胶得率为２．１％，制得的果胶半乳糖醛酸的含量大于６０％，酯化度（ＤＥ值）大于６０％，胶凝度为１６５级。产品质量符合食品化学法规标准（ＦＣＣ）。

In this article the technological conditions of the pectin preparation from watermelon rinds based on two methods of diluted H2SO3 solution extraction (containing a small amount of H3PO4) and ethanol precipitation extraction was discussed.The temperature,time of extraction,the effect of pH value of extraction solusion on the pectin productivity and the gelation intensity were also discussed.It was proved that the best extraction procedure was as follows .Put a certain amount of watermelon rinds into the H2SO3 solution of pH value 2.8 (containing a small amount of H3PO4),heat it to 95℃,and then kept it unedr a constant temperature for 120 min.The extraction solution being filtered and concentrated,added 95% ethanol of the same volume as that of the concentration solution to precipitate the pectin.The productivity of the pectic thus prepared will be 2.1%,and the content of the semi-lactose aldehydic acid over 60%,the DE(Degree of Esterification)over 60% and the DG(Degree of Gelation)at level 165.The quality of the product confirms to the standard of FCC.