库仑滴定法用电生成氧化剂作为评估干邑白兰地和白兰地抗氧化性能的工具。

Coulometric titration with electrogenerated oxidants as a tool for evaluation of cognac and brandy antioxidant properties.

机构信息

Analytical Chemistry Department, Kazan Federal University, Kremlyevskaya, 18, Kazan 420008, Russian Federation.

出版信息

Food Chem. 2014 May 1;150:80-6. doi: 10.1016/j.foodchem.2013.10.133. Epub 2013 Nov 4.

DOI:10.1016/j.foodchem.2013.10.133

Abstract

Stoichiometric coefficients for reactions of cognac antioxidants with coulometric titrants (electrogenerated bromine and hexacyanoferrate(III) ions) have been found. Ellagic and gallic acids react with both titrants while aldehydes (vanillin, syringic and coniferaldehyde) - with electrogenerated bromine only. Furfurals do not show significant reactivity toward both oxidants. Cognac and brandy total antioxidant capacity (TAC) and ferric reducing power (FRP) based on reactions with electrogenerated bromine and hexacyanoferrate(III) ions, respectively, have been evaluated. Both parameters for cognacs are statistically significant higher than for brandies and grow with the age increase. Beverages under investigation has shown relatively high antiradical activity toward 2,2-diphenyl-1-picrylhydrazyl (7-92% and 5-93% for cognacs and brandies, respectively). Total phenolics content has been evaluated by Folin-Ciocalteu method. Older beverages represent the higher phenolics content caused by more time of extraction from oak barrels. Positive correlations (r=0.8077-0.9617) have been observed for TAC and FRP with antiradical activity and total phenolics content.

摘要

已发现干邑白兰地抗氧化剂与库仑滴定剂（电生成溴和六氰合铁(III)离子）反应的化学计量系数。鞣花酸和没食子酸与两种滴定剂反应，而醛（香草醛、丁香醛和松柏醛）仅与电生成的溴反应。糠醛对两种氧化剂均无明显反应活性。基于与电生成溴和六氰合铁(III)离子的反应，评估了干邑白兰地和白兰地的总抗氧化能力（TAC）和铁还原能力（FRP）。干邑白兰地的这两个参数均显著高于白兰地，且随陈酿时间的增加而增加。所研究的饮料对 2,2-二苯基-1-苦基肼（DPPH）具有相对较高的自由基清除活性（干邑白兰地和白兰地的清除活性分别为 7-92%和 5-93%）。总酚含量采用福林-希卡尔法评估。由于从橡木桶中提取的时间更长，较老的饮料具有更高的酚类含量。TAC 和 FRP 与自由基清除活性和总酚含量之间存在正相关关系（r=0.8077-0.9617）。