摘要:文章研究《专业方向实验Ｉ》中的实验果胶的提取，在原果胶提取实验中学生的提取率低，果胶品质不佳，实验不成功。文章通过研究、改进实验手段，从而得到更高产率和更高质量的果胶，提高教学质量。在原实验基础上，对酸提取法进行研究改进，把单一的盐酸提取改为盐酸与草酸的混酸溶液提取，除去活性炭脱色，用无水乙醇沉淀法分离，增加无水乙醇的洗涤次数为3次。通过单因素实验，考察水浴温度、保温时间、混酸 (HCl-H2C2O4)调节的提取液的pH值、料液比四个因素对果胶提取率的影响，并对单因素实验的因素进行正交优化。结果表明：以处理过的新鲜柑橘皮为原料，按1:5 (g/mL)的料液比加入蒸馏水，用混酸 (HCl-H2C2O4)调节提取液的pH值到2，100℃水浴保温50min后，采用无水乙醇沉淀法提取果胶，提取出的果胶再用无水乙醇洗涤，放入60℃-70℃烘箱烘干即得果胶成品。改进后的实验方法提高果胶的提取率平均在30%，提高了得率，简化了实验步骤。
关键词：果胶；混酸提取；乙醇沉淀；提取率
Abstract:Articles in the study of the specialization experiment I experimental extraction of pectin in the same low rate of extraction of pectin extraction experiment of middle school students, poor quality pectin, experiment was not successful. Means of article improvement through research, experimentation, resulting in higher yield and better quality of pectin, improving the quality of teaching. In the original experiment, based on studies on acid-extraction method to improve, hydrochloric acid extraction from single to a mixture of hydrochloric acid and oxalic acid solution, get rid of decoloration, separated by ethanol precipitation, ethanol increase washing times for 3 times. By orthogonal experiments to study the water bath temperature and holding time, mixed acid (hydrochloric acid - oxalic acid), adjust the pH value, extract liquid effect than the four factors on extraction of pectin and orthogonal optimization experimental factors on the single factor. Results indicates that: to processing had of fresh orange skin for raw materials, by 1:5 (g/mL) of material liquid than joined distilled water, with mixed acid (hydrochloric acid - oxalic acid) regulation extraction liquid of pH value to 2,100 ℃ water bath insulation 50min housed no water ethanol precipitation method extraction pectin, extraction out of pectin then with no water ethanol washing, into 60 ℃- 70 ℃ oven drying is was pectin finished. Improved experimental method to increase the rate of extraction of pectin from 30%, the average, raising rates, simplifies the experimental steps.
Keywords: Pectin；Mixed acid extraction；Ethanol precipitation；Extraction rate
