Fast, sensitive, and sustainable colorimetric detection of chlorogenic acid in artichoke waste material
Doretta Cuffaro, Pasquale Palladino, Maria Digiacomo, Simone Bertini, Maria Minunni, Marco Macchia
Abstract
Caffeoylquinic acids (CQAs) are nutraceutical polyphenols highly represented in natural sources, including artichoke waste (AW). In this study a colorimetric method for rapid and sustainable detection of a 5-CQA isomer (Chlorogenic acid) in AW extract was developed by using alkaline Tris buffer (10 mmol L −1 , pH 9) to generate a yellow color associated with 5- to 3-CQA isomerization reaction, as suggested by NMR and MS analyses. The strong absorbance at 360 nm was followed by standard UV–Vis methodology. The colorimetric assay was exploited for detection of 5-CQA into leaf extract from artichoke, obtaining a value of 15.2 ± 0.3 μg/mg of dry extract, in agreement with HPLC analysis (14.3 ± 0.7 μg/mg, 106 ± 2 % recovery) used as validation technique, with excellent linear correlation and precision (R 2 = 0.9996, av RSD% = 3.2 %). The method is fast and selective, offering a valuable tool for nutraceuticals identification and food waste valorization. • Caffeoylquinic acids (CQAs) are phenolic plant metabolites abundant in artichokes. • 5-CQA and 1,5-CQA solutions give yellow color in Tris buffer 10 mM at pH 9. • A selective colorimetric assay allows the determination of CQAs in artichoke waste.