ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Natural pigments in anionic layered clays as fluorescent indicators for volatile amines with antimicrobial properties

Ligia Todan, Mariana Voicescu, Daniela C. Culita, Irina Atkinson, Elena M. Soare, Iuliana Raut, and Mariana Constantin

Ilie Murgulescu Institute of Physical Chemistry of the Romanian Academy, Bucharest, Romania

E-mail: l_todan@yahoo.co.uk

Received: 16 December 2024  Accepted: 11 July 2025

Abstract:

Quercetin, a naturally occurring flavonoid, is of interest both as a dye as well as a biologically active molecule. The fluorescence properties of quercetin can be used to study interactions with specific targets under certain environmental conditions, as these interactions lead to changes in quercetin’s chemical structure. The present study proposes a new approach for detecting biogenic amines—an indicator of food spoilage—and extending food shelf-life by preparing composites based on quercetin and anionic layered minerals, both in their native form and modified with surfactants. The structural and spectroscopic characteristics of the quercetin-matrix system were analysed by X-ray diffraction, Fourier-transform infrared spectroscopy, UV–visible spectroscopy, and fluorescence experiments. Additionally, the antimicrobial activity of the obtained powders was evaluated. The powders were exposed to pyridine and ammonia as reference amines, and their fluorescence response was measured. Interactions between quercetin and the carrier-surfactant system were evidenced which promoted the fluorescence of the composites in the presence of amines compared to quercetin alone. Furthermore, the quercetin-layered minerals-surfactant system shows potential as an effective indicator for volatile amines. Notably, the system without surfactant exhibits antimicrobial activity, demonstrating its ability to preserve food quality.

Keywords: Quercetin; Layered double hydroxides; Fluorescence; Antimicrobial activity; Biogenic amines

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04251-w

Chemical Papers 79 (10) 7117–7125 (2025)