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Fast and Simultaneous Determination of Antioxidant Activity, Total Phenols and Bitterness of Red Wines by a Multichannel Amperometric Electronic Tongue
Author(s) -
Merkyte Vakare,
Morozova Ksenia,
Boselli Emanuele,
Scampicchio Matteo
Publication year - 2018
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201700652
Subject(s) - electronic tongue , chemistry , phenols , phenol , amperometry , antioxidant , chromatography , taste , wine , analytical chemistry (journal) , food science , electrode , biochemistry , organic chemistry , electrochemistry
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 E 1 =+400 and E 2 =+800 mV) were followed by other two electrodes (poised at E 3 =+800 and E 4 =−400 mV). This configuration allowed to gain information on the content of the antioxidants activity (E 1 ) and total phenols (E 2 and E 3 ). E 1 /E 2 was used to express the proportion of strong vs. weak antioxidants. E 3 /E 4 was used to express an index of reversibility. Finally, the ratio E 2 /E 3 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 2 =0.94). Bitterness was correlated with the descriptors of the e‐tongue (R 2 =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.