Folin-Ciocalteu比色法测定核桃青皮果蔬酵素总多酚含量

Determination of total polyphenol in walnut green husk fruit and vegetable compound ferment by Folin-Ciocalteu colorimetry

以没食子酸为标准品，探究福林-酚（Folin．Ciocalteu）比色法检测核桃青皮果蔬酵素总多酚含量的最优条件，对检测波长、碳酸钠和Folin—Ciocalteu试剂用量、显色温度及显色时间进行了优化，并对该分析方法进行了评价。结果表明，总多酚含量测定的最优条件为检测波长696nln、样品液1mL、10％Folin．Ciocalteu试剂2．5mL、12％碳酸钠溶液1mL、显色温度45℃，显色时间0．5h。多酚含量在0～6μg／mL范围内与吸光值呈良好的线性关系（y=0．07243x-0．00091，R^2=0．99967），该法平均回收率为102．2％（RSD=2.35％）。该方法准确度高、重复性好，适于核桃青皮果蔬酵素总多酚含量的测定，此条件下测得核桃青皮果蔬酵素总多酚含量为3．26mg／mL。

Using gallic acid as standard, the optimal condition on determination of total polyphenol content in walnut green husk fruit and vegetable compound ferment by Folin-Ciocalteu colorimetry was studied. The detection wavelength, the sodium carbonate solution and Folin-Ciocalteu reagent addition, reaction temperature and time were optimized. In addition, the colorimetry was further assessed. The results indicated that the optimum con- ditions for total polyphenol determination in walnut green husk ferment were as follows： wavelength 696 rim, sample 1 ml, 10% Folin-Ciocalteul reagent 2.5 ml and 12% sodium carbonate solution 1 ml, reaction temperature 45 ℃ and time 0.5 h. Under the conditions, the absorbance increased linearly with the concentration of gallic acid in the range of 0-6 p.g/ml （y= 0.072 43x-0.000 91, R^2=0.999 67）. The average recovery rate was 102.2% with the relative standard deviations of 2.35%. The method was suitable for determining total polyphenol content in walnut green husk fruit and vegetable compound ferment with high accuracy and repeatability, and the total polyphenol content in walnut green husk fruit and vegetable com- pound ferment was 3.26 mg/ml.