Spectroscopy, Microscopy and Fluorescence Imaging of Origanum vulgare L. Basis for Non-destructive Quality Assessment

JOHANNA MENDES NOVO; ANALÍA IRIEL; MARIA CLAUDIA MARCHI; M. GABRIELA LAGORIO

PHOTOCHEMISTRY AND PHOTOBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2013 vol. 89 p. 1383 - 1390

0031-8655

The organs of Origanum vulgare L. plant were examined by optical microscopy, scanning electron microscopy and autouorescence imaging. The different organs were also studied spectroscopically. Fluorescence emission spectra were recorded for intact inorescences, leaves and stems. Several uorescence ratios (Blue/Red, Blue/Far-red, Green/Red and Green/Far-red), which varied depending on the considered organ of the plant, were derived. For leaves, a dependence of uorescence spectra with water content was obtained as well. The intact samples were also analyzed by Attenuated Total Reectance Fourier Transform Infrared Spectroscopy. These spectra were transformed to the Remission function depending on the wavenumber and two absorption bands (811 and 1740 cm1), which displayed differences according to the plant organ sampled, were detected. These results were consistent with higher carvacrol content in inorescences. The spectroscopic results were connected with the microscopic observation and with the presence of relevant nutraceutics contained in the plant. The optical indexes derived in this work may serve as potential indicators to be explored in the development of nondestructive methods for oregano quality assessment.