Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7583873 | Food Chemistry | 2019 | 11 Pages |
Abstract
Phenolic extracts from cv Tempranillo grapes subjected to water stress and irrigation treatment, both of them with high and low crop load, were analyzed by front-face fluorescence. Excitation-emission matrices (EEMs) were analyzed by means of unsupervised parallel factor analysis (PARAFAC), PARAFAC supervised by linear discriminant analysis, and discriminant unfolded partial least-squares. All algorithms allowed to differentiate between water stress and irrigation grape samples when the fluorescence maxima region of catechin and epicatechin, and resveratrol was considered. A central composite design was employed for the calibration of catechin, epicatechin and resveratrol. Resveratrol was quantified by U-PLS in both, irrigated and water stressed samples, and levels between 3.46â¯Â±â¯0.22 and 4.67â¯Â±â¯0.08â¯Î¼gâ¯mLâ1 and 2.43â¯Â±â¯0.60 and 3.03â¯Â±â¯0.10â¯Î¼gâ¯mLâ1, respectively, were found. PARAFAC only allowed the determination of the sum of catechin plus epicatechin (R2â¯=â¯0.9397). The determination of total catechin plus epicatechin by means of PARAFAC was successfully validated by liquid chromatography.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Manuel Cabrera-Bañegil, Esperanza Valdés-Sánchez, Daniel Moreno, Diego Airado-RodrÃguez, Isabel Durán-Merás,