Electrochemical Analysis of Coffee Extractions at Different Roasting Levels Using a Carbon Nanotube Electrode

This study reports on the electrochemical analysis of coffee extractions at different roasting levels by using a carbon nanotube (CNT) electrode. The roasting levels, ranging from 1 (low) to 6 (high), were determined according to the roasting time after fixing the roasting temperature. Level 1 roasting resulted in light roasted beans and level 6 in dark roasted ones. Based on the roasting level, the concentration of chlorogenic acids, including 3-caffeoylquinic (3CQ), 4-caffeoylquinic (4CQ), and 5-caffeoylquinic (5CQ) acid, can be determined. Cyclic voltammetry (CV) experiments revealed that the reduction current at +0.27 V was proportional to the concentration of chlorogenic acids. High-performance liquid chromatography (HPLC) revealed an inverse correlation between the roasting level and chlorogenic acid amount. The total amounts of chlorogenic acids in coffee extractions determined by HPLC were in agreement with those obtained by CV using the CNT electrode at roasting levels 1 - 5. At level 6, the amount of chlorogenic acids determined by the current peak was larger than that detected by HPLC. As a result, the chlorogenic acid amount was overestimated in the CV experiment at +0.27 V, indicating that electrochemically active materials were generated at level 6. The CV profile showed that the reduction peak at +0.10 V increased with an increase in roasting level. Thus, the peak intensity at +0.10 V can be used to evaluate the roasting level even if the concentration or dilution conditions are provided.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:37

Enthalten in:

Analytical sciences : the international journal of the Japan Society for Analytical Chemistry - 37(2021), 2 vom: 10. Feb., Seite 377-380

Sprache:

Englisch

Beteiligte Personen:

Wada, Ryotaro [VerfasserIn]
Takahashi, Shota [VerfasserIn]
Muguruma, Hitoshi [VerfasserIn]
Osakabe, Naomi [VerfasserIn]

Links:

Volltext

Themen:

Carbon nanotube
Chlorogenic acid
Coffee
Coffee infusion
Cyclic voltammetry
Journal Article
Nanotubes, Carbon
Plant Extracts
Redox reaction
Roasting level

Anmerkungen:

Date Completed 27.09.2021

Date Revised 08.08.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.2116/analsci.20N021

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM314937277