| Title: | "The problem of 2,4,6-trichloroanisole in cork planks studied by attenuated total reflection infrared spectroscopy: proof of concept" |
| Author(s): | Garcia AR; Lopes LF; Brito de Barros R; Ilharco LM; |
| ISSN/ISBN: | 1520-5118 (Electronic) 0021-8561 (Linking) |
| Abstract: | "Attenuated total reflection infrared spectroscopy (ATR-IR) proved to be a promising detection technique for 2,4,6-trichloroanisole (TCA), which confers organoleptic defects to bottled alcoholic beverages, allowing the proposal of a criterion for cork plank acceptance when meant for stopper production. By analysis of a significant number of samples, it was proved that the presence of TCA, even in very low concentrations, imparts subtle changes to the cork spectra, namely, the growth of two new bands at approximately 1417 (nuC horizontal lineC of TCA ring) and 1314 cm-1 (a shifted nuCC of TCA) and an increase in the relative intensities of the bands at approximately 1039 cm-1 (deltaCO of polysaccharides) and approximately 813 cm-1 (tauCH of suberin), the latter by overlapping with intense bands of TCA. These relative intensities were evaluated in comparison to a fingerprint of suberin (nuasC-O-C), at 1161 cm-1. On the basis of those spectral variables, a multivariate statistics linear analysis (LDA) was performed to obtain a discriminant function that allows classifying the samples according to whether they contain or not TCA. The methodology proposed consists of a demanding acceptance criterion for cork planks destined for stopper production (with the guarantee of nonexistence of TCA) that results from combining the quantitative results with the absence of the two TCA correlated bands. ATR infrared spectroscopy is a nondestructive and easy to apply technique, both on cork planks and on stoppers, and has proven more restrictive than other techniques used in the cork industry that analyze the cleaning solutions. At the level of proof of concept, the method here proposed is appealing for high-value stopper applications" |
| Keywords: | "Anisoles/*analysis Discriminant Analysis *Food Contamination Food Packaging/instrumentation Odorants/analysis Portugal Quercus/*chemistry Spectrophotometry, Infrared Taste Volatile Organic Compounds/*analysis Wine/analysis;" |
| Notes: | "MedlineGarcia, Ana R Lopes, Luis F Brito de Barros, Ricardo Ilharco, Laura M eng Research Support, Non-U.S. Gov't 2014/12/10 J Agric Food Chem. 2015 Jan 14; 63(1):128-35. doi: 10.1021/jf503309a" |
