葡萄中有机酸的提取工艺参数优化及同时测定

Optimization of Extraction Parameters and the Simultaneous Determination of Organic Acids in Grapes

摘要:

根据单因素试验结果与响应面分析法中的Box-Behnken 试验设计原理选取试验因素与水平，对葡萄有机酸提取率有影响的料液比、乙醇体积分数和pH值3个因素进行优化；结果表明：葡萄有机酸提取的最佳工艺参数为料液质量体积比1 g∶16 mL，乙醇体积分数76.37%，pH值11.87；在此条件下，葡萄有机酸质量分数为216.907 ?滋g/g。硫酸铜与柠檬酸、酒石酸和苹果酸反应生成的络合物吸收光谱重叠严重，用光度法难以进行单一组分的测定。采用偏最小二乘-光度法对柠檬酸、酒石酸和苹果酸模拟混合试样进行同时测定，并应用于葡萄有机酸的测定。对模拟混合试样，回收率99.6%～99.8%；RPEs为0.64%～0.67%。

Abstract:

According to the results of single factor experiments and response surface analysis of Box-Behnken experimental design principle, the factors that influence the extraction rate of the organic acids in grapes were optimized. The 3 factors were solid to liquid ratio, the volume fraction of ethanol and pH value. The results showed that the optimum extraction conditions for organic acids in grapes were as follows: the solid to liquid ratio was 1∶16(g/mL), the volume fraction of ethanol was 76.37% and the pH value was 11.87. Under this condition, the extraction mass fraction of organic acids in grapes was 216.907 μg/g. The absorption spectra of complexes that generated by citric acid, tartaric acid and malic acid with copper sulfate were overlapping seriously. So it's very difficult to separate each component with photometric method. In this paper, the partial least squares method was used for simultaneous determination of the simulation ofmixed citric acid, tartaric acid and malic acid complexes. And the method was also be used in the determination of organic acids in grapes. To the analog mixed sample the recovery rate was 99.6%~99.8%, and the RPEs was 0.64%~0.67%.