Institute of Chemistry, University of Silesia, 9 Szkolna Street, 40-006 Katowice, Poland.
Faculty of Chemistry, University of Wroclaw, 14 Joliot Curie Street, 50-383 Wroclaw, Poland.
Talanta. 2015 Jun 1;138:64-70. doi: 10.1016/j.talanta.2015.01.026. Epub 2015 Feb 12.
The performance of the recently proposed excitation-emission fluorescence method was compared to the method using infrared measurements for the evaluation of the antioxidant properties of intact samples and extracts that had been obtained from tomato pastes. The oxygen radical absorbance capacity assay (ORAC) was applied in order to estimate the antioxidant capacity of the extracts, while the Folin-Ciocalteu reagent was adopted for the evaluation of the total phenolic content. The optimal extraction conditions for tomato pastes (three minutes of sonication under 80°C) were determined using the central composite design. Chemometric models such as the partial least squares regression and its N-way variant were further constructed in order to predict the antioxidant capacity or total phenolic content of the samples using either the IR or fluorescence spectra. The prediction errors that were obtained for the total antioxidant content were evaluated as the Trolox equivalents from the ORAC assay and were found to be equal to 2.011 (14.21%) for the fluorescence and 2.426 (17.15%) for the IR spectra, respectively. The prediction errors of the total phenolic content expressed as gallic acid equivalents were 0.067 (10.78%) for the fluorescence and 0.033 (5.36%) for the IR spectra, which were used as independent variables in the regression models.
最近提出的激发-发射荧光法的性能与使用红外测量法的性能进行了比较，用于评估完整样品和从番茄糊中提取的提取物的抗氧化性能。应用氧自由基吸收能力测定法（ORAC）来估计提取物的抗氧化能力，而采用 Folin-Ciocalteu 试剂来评估总酚含量。使用中心复合设计确定了番茄糊的最佳提取条件（80°C 下超声 3 分钟）。进一步构建了偏最小二乘回归及其 N 路变体等化学计量模型，以便使用 IR 或荧光光谱来预测样品的抗氧化能力或总酚含量。使用 ORAC 测定法获得的总抗氧化含量的预测误差被评估为 Trolox 当量，对于荧光光谱分别为 2.011（14.21%），对于 IR 光谱为 2.426（17.15%）。以没食子酸当量表示的总酚含量的预测误差对于荧光光谱为 0.067（10.78%），对于 IR 光谱为 0.033（5.36%），它们分别作为回归模型中的自变量。
