Fluorescence, Reflectance and Imaging as Tools in Devices for Artificial Vision. Evaluation of Yerba Mate Composition

TAMARA PARAPUGNA; MARÍA GABRIELA LAGORIO

Córdoba

Congreso; 16th international Congress on Photobiology; 2014

International Union of Photobiology

Yerba mate (YM) is massively produced and consumed as an infusion in South America [1]. This product is exclusively obtained from dried leaves, slightly toasted and milled, of Ilex paraguariensis Saint Hilaire, mixed or not with fragments of young dried branches, petioles and peduncles. For its commercialization YM must have a minimum percentage of leaves according to a standard classification. Until now, composition quantification (% leaves vs % sticks) is mechanically performed [2], thus development of new methods are still pending. In this work a quantification method using solid-phase molecular fluorescence or alternately diffuse reflectance spectroscopy (DRS) is proposed. In both cases, linear correlations between processed signals and composition were found (Figure 1-2). DRS is a more sensitive method. Image technique using a digital scanner is being developed.   Figure 1. Emission spectra (lexc 360 nm) for different YM compositions. Inset: Correlation Fluorescense emisision intensitity (If) (469 nm)/If (680 nm) vs. % sticks and linear fit ( y = (0.0169±0.0004)*x + 1.03 ±0.02; R2= 0.99384)   Figure 2. Reflectance spectra for different YM compositions. Inset: Correlation % Reflectance (669 nm) vs. % sticks and linear fit ( y = (0.45 ±0.02)*x + 16 ±1; R2= 0.98996)