RP-HPLC法测定SO_2处理前后新疆无核葡萄干中的B族维生素

建立了高效液相色谱同时测定SO_2处理前后无核葡萄干中4种B族维生素(V_(B1),V_(B2),V_(B3)和V_(B6))的分析方法。考察了流动相组成、p H值及梯度洗脱程序对分离效果的影响。最终采用pH 4.4缓冲溶液和乙腈作为流动相进行梯度洗脱,4种B族水溶性维生素的线性范围为0.1~20 mg/L,r20.999,检出限为0.013~0.064 mg/L,方法的平均回收率为83.0%~101.4%,相对标准偏差为0.6%~4.8%。同时利用该法对SO_2处理前后无核葡萄干中4种维生素含量的影响进行研究。结果表明,空白无核葡萄干中V_(B6)的含量最大,V_(B1)含量较低;但SO_2处理对葡萄干中V_(B1)的含量影响最大,其它3种B族维生素的含量变化不大。该方法简便,快速,准确性和重现性均较好,可用于葡萄干中B族维生素的测定。     

Comprehensive Evaluation of Antioxidant Activity of Ribes berry Fruit Species: A Chemometric Approach

Currant fruit extracts were characterized by (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, 2,2-azinobis-3 ethyl benzothiazoline-6-sulfonic acid cation decolorization activity, total reducing power, cupric ion reducing antioxidant power, and ferric ion reducing antioxidant power (FRAP) assays to evaluate their antioxidant activity. All five antioxidant assays revealed the highest antioxidant activity to be present for the black currants. The highest concentrations of phenolics were present in the black currants (1690?±?10?mg gallic acid equivalents (GAE)/100?g fresh weight), while the lowest value was obtained in the white currants (579?±?5?mg GAE/100?g fresh weight). The correlation between the total phenolic content and antioxidant activity assays was evaluated using regression analysis. A significant positive correlation was obtained between the total phenols and the cupric ion reducing antioxidant power (r?=?0.97, p?r?=?0.93, p?currants as a distinctive cluster.