Rocío B. Pellegrino Vidal

A new strategy is proposed for second-order data fusion based on the simultaneous modeling of two data sets using the multivariate curve resolution-alternating least-squares (MCR-ALS) model, applying a new constraint during the ALS stage, called "Proportionality of Scores". This approach allows for the fusion of data from different sources, without requiring common dimensionality, and enables the application of specific constraints to each data set. This strategy was applied to the determination of five pharmaceutical contaminants (naproxen, danofloxacin, ofloxacin, sarafloxacin, and enoxacin) in environmental water samples, by fusing two sets of excitation-emission fluorescence matrices, measured before and after photochemical derivatization. The predictive performance of the fused model was compared to individual PARAFAC models built for each fluorescence data set, showing that data fusion significantly increases precision and accuracy, as indicated by the elliptical joint confidence region test. Data fusion allowed improvement of relative errors of prediction, from 13-32% to 8-15% in validation samples and from 25-121% to 13-20% in real samples. The advantages of data fusion were evident in both cases, particularly in instances of substantial signal overlap between analytes or the presence of uncalibrated interferents with similar profiles, as demonstrated by the superior predictive capacity achieved through the proposed strategy.

Background and goals The search for strategies to improve the quality of Argentine Malbec wines has led to experimentation with production of wines that achieve superior sensory properties after prolonged bottle aging. During aging, a series of complex oxidation-reduction and polymerization reactions occur. These reactions, responsible for changing the sensory aspects of wines, can be influenced by a variety of factors (terroir, winemaking practices, storage conditions, etc.). Thus, understanding the chemical processes that take place during bottle aging could significantly impact the enology industry. This work evaluates the evolution of aromatic profiles over time in Malbec wines from Mendoza and California. Methods and key findings Wines from Mendoza and California were obtained under standardized conditions. Determination of volatile profiles was carried out on young wines by gas chromatography-mass spectrometry and, subsequently, after seven years of aging. The effect of time and region on volatile profiles was investigated. The aging time showed a significant effect on the aromatic composition. While the profiles obtained after seven years were less diverse than at bottling, they retained a significant number of desirable volatile compounds. Additionally, the volatile profiles of the aged wines still permitted differentiation of samples by country of origin. Conclusions and significance The information obtained enabled us to assess the evolution of aromatic profiles during bottle aging of Malbec wines from Mendoza and California, and could be useful in decision-making regarding the blending, marketing, and storage of these wines.