苹果籽油中植物甾醇的提取及分光光度法含量测定研究

本实验采用皂化法提取苹果籽油中甾醇化合物，并采用薄层色谱法- 磷硫铁分光光度比色法对其进行定量分析。研究了最佳提取工艺、展开剂的组成及显色反应的条件，并探讨了该方法的精密度、稳定性及回收率等。甾醇的最佳提取工艺条件为：料液比1:4、KOH- 乙醇浓度0.5mol/L、皂化时间120min、皂化温度85℃；薄层层析最适宜的展开剂为乙醚:石油醚(3:7，V/V)，显色剂为0.02% 罗丹明6B- 乙醇溶液，经过薄层分离后在紫外灯照射下呈现紫色谱带，与磷硫铁显色剂反应能生成稳定的紫色物质，在波长660nm 处具有最大吸收值。分光光度法测定的最佳显色条件为乙醇用量2ml，磷硫铁显色剂2ml，50℃反应15min，该方法具有快速、精密度高，重现性和回收率好，且操作简单等优点。

Extraction and Spectrophotometry Determination of Sterol in Apple Seed Oil

In this study, the extraction technology of sterol from apple seed oil was confirmed by orthogonal test and quantitatively analyzed by thin layer chromatography-spectrophotometry. The results showed the optimal conditions extraction of sterol are as following: solid-liquid ratio 1:4, alkaline concentration 0.5 mol/L, saponification at 85 ℃ for 120 min, and the optimum developer solvent and color reagent for thin layer chromatography are aether: petroleum aether (3:7, V/V) and 0.02% alcoholic solution of butylrhodamin 6B, respectively. Sterol from apple seed oil represents purple band under ultraviolet lamp after TLC, and forms stabile green matter, which has the maximum absorbance at the wavelength of 660 nm, via reaction with H3PO4- H2SO4-FeCl3 color reagent. Moreover, the optimum color conditions of spectrophotometry are ethanol volume 2 ml, H3PO4- H2SO4-FeCl3 color reagent volume 2 ml, color reaction time 15 min and temperature 50 ℃. This method is easy and rapid with high precision and excellent reproducibility.