Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia.
Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia.
Food Chem. 2015 May 1;174:147-53. doi: 10.1016/j.foodchem.2014.11.030. Epub 2014 Nov 11.
The reactivity of SO2 with the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and in Folin Ciocalteu (FC) assays was analysed under different experimental conditions. There was significantly higher reactivity between SO2 and DPPH in buffered methanol than in methanol alone. When DPPH and FC assays were performed in a mixture of caftaric acid and SO2, there were synergistic effects that were more pronounced with the FC assay. Phenolics are an important parameter of wine quality, and their accurate characterisation in wine is essential. Analysis of white wines with DPPH and FC assays overestimates the contribution of phenolics to the antioxidant potential (AOP). SO2 contributes (from 20% to 45%) to the AOP of the white wines analysed. As SO2 reactivity depends highly on buffer composition, pH, time of incubation and other compounds, e.g. phenolics and aldehydes, different experimental protocols can produce large variations in AOPs, and therefore control of experimental conditions is extremely important.
二氧化硫（SO2）与 2,2-二苯基-1-苦基肼自由基（DPPH）和福林-希考尔特（FC）反应的活性在不同的实验条件下进行了分析。在缓冲甲醇中，SO2 与 DPPH 之间的反应活性明显高于甲醇。当 DPPH 和 FC 反应在咖啡酸和 SO2 的混合物中进行时，存在协同作用，FC 反应更为明显。酚类物质是葡萄酒质量的一个重要参数，因此准确描述葡萄酒中的酚类物质至关重要。用 DPPH 和 FC 反应分析白葡萄酒会高估酚类物质对抗氧化能力（AOP）的贡献。SO2 （从 20%到 45%）对白葡萄酒的 AOP 有贡献。由于 SO2 的反应活性高度依赖于缓冲液组成、pH 值、孵育时间和其他化合物，例如酚类物质和醛类，不同的实验方案可能会导致 AOP 产生很大的变化，因此对实验条件的控制极为重要。
