An electronic tongue based on a flow injection system equipped with a multichannel amperometric detector was used to determine the antioxidant activity, total phenols and bitter taste of red wines. The detector composed of four glassy carbon electrodes, arranged in a square configuration, where two parallel electrodes (poised at E1 = +400 and E2 = +800 mV) were followed by other two electrodes (poised at E3 = +800 and E4 = 400 mV). This configuration allowed to gain information on the content of the antioxidants activity (E1) and total phenols (E2 and E3). E1/E2 was used to express the proportion of strong vs. weak antioxidants. E3/E4 was used to express an index of reversibility. Finally, the ratio E2/E3 was used to control the system. Overall, the four electrodes led to seven variables, which provided a characteristic pattern profile. The eleven variables in total were analyzed by principal component analysis (PCA) to determine, the antioxidant activity, total phenol content and bitterness value of red wine samples. The results of antioxidant activity were correlated with the Folin Ciocalteu index (R =0.94). Bitterness was correlated with the descriptors of the e-tongue (R =0.81). Overall, the analysis with the proposed electronic tongue is simple (only a dilution is required), fast (the analysis takes less than 20 seconds per sample), objective (precision within 5 %, expressed as RSD%) and cheap compared to classical sensory analysis.

中文翻译：

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多通道安培电子舌快速同时测定红葡萄酒的抗氧化活性、总酚和苦味

基于配备多通道电流检测器的流动注射系统的电子舌被用于测定红葡萄酒的抗氧化活性、总酚和苦味。检测器由四个玻璃碳电极组成，呈方形排列，其中两个平行电极（位于 E1 = +400 和 E2 = +800 mV）后面是另外两个电极（位于 E3 = +800 和 E4 = 400毫伏）。这种配置允许获得有关抗氧化剂活性 (E1) 和总酚 (E2 和 E3) 含量的信息。E1/E2 用于表示强抗氧化剂与弱抗氧化剂的比例。E3/E4 用于表示可逆性指数。最后，比率 E2/E3 用于控制系统。总的来说，四个电极导致了七个变量，提供了一个特征模式轮廓。通过主成分分析 (PCA) 分析总共 11 个变量，以确定红葡萄酒样品的抗氧化活性、总酚含量和苦味值。抗氧化活性的结果与 Folin Ciocalteu 指数相关（R = 0.94）。苦味与电子舌的描述相关（R = 0.81）。总体而言，与经典感官相比，所提出的电子舌的分析简单（只需稀释）、快速（每个样品的分析时间不到 20 秒）、客观（精度在 5% 以内，表示为 RSD%）且便宜分析。抗氧化活性的结果与 Folin Ciocalteu 指数相关（R = 0.94）。苦味与电子舌的描述相关（R = 0.81）。总体而言，与经典感官相比，所提出的电子舌的分析简单（只需稀释）、快速（每个样品的分析时间不到 20 秒）、客观（精度在 5% 以内，表示为 RSD%）且便宜分析。抗氧化活性的结果与 Folin Ciocalteu 指数相关（R = 0.94）。苦味与电子舌的描述相关（R = 0.81）。总体而言，与经典感官相比，所提出的电子舌的分析简单（只需稀释）、快速（每个样品的分析时间不到 20 秒）、客观（精度在 5% 以内，表示为 RSD%）且便宜分析。