油茶皂素脱色及色泽评价方法比较研究

采用过氧化氢/凹凸棒土耦合体系对油茶皂素进行脱色, 考察了过氧化氢用量、温度、时间和凹凸棒土用量对脱色率的影响, 探究了皂素脱色的最佳条件, 并比较了分光光度计法、分光辐射亮度计法、罗维朋比色计法、色阶比色法和直观拍照法等不同色泽评价方法对皂素颜色测定的优劣。研究结果显示: 最佳脱色条件为H₂O₂用量6%, 温度80℃, 时间3h, 凹凸棒土用量3%, 此条件下皂素呈现乳白色。5种色泽评价结果基本相近。分光光度计法可对茶皂素色泽精确定量分析; 分光辐射亮度计法适用于较小色差情况下的颜色评价; 罗维朋比色计法在需要对茶皂素溶液进行较广泛的色泽分析场景中具有优势; 色阶比色法操作简便, 可行性强; 直观拍照能对以上方法佐证。

Comparison of Decolorization and Color Evaluation Methods of Camellia oleifera Saponin

The coupling system of hydrogen peroxide and attapulgite was used to decolorize Camellia oleifera saponin. The effects of the amount of hydrogen peroxide, temperature, time, and attapulgite amount on the decolorization rate were investigated, and the optimal conditions for decolorization of saponins were explored. The advantages and disadvantages of different color evaluation methods, such as spectrophotometer, spectroradiometer, Lovibon colorimeter, color scale colorimeter, and visual photography, on the color determination of saponins were compared. The results showed that the optimum decolorization conditions were 6% H₂O₂, 80 ℃, 3 h, 3% attapulgite, and the milky white Camellia oleifera saponin. The results of five color evaluation methods are basically similar. The color of Camellia oleifera saponin could be accurately and quantitatively analyzed by spectrophotometer. The spectroradiometer method was suitable for color evaluation with small color difference. The Lovibond colorimeter method had advantages in the scene where a wide range of color analysis of Camellia oleifera saponin solution was required. Color scale colorimetry has simple operation and high feasibility. Visual photography could support the above methods.