In this article, a combination of non-destructive NIR spectroscopy and machine learning techniques was applied to predict the texture parameters and the total soluble solids content (TSS) in intact berries. The multivariate models obtained by building artificial neural networks (ANNs) and applying partial least squares (PLS) regressions showed a better prediction ability after the elimination of uninformative spectral ranges. A very good prediction was obtained for TSS and springiness (R 0.
View Article and Find Full Text PDFTexture characteristics are valuable parameters in the perceived quality and overall acceptability of fresh fruit. The characterization of grape texture attributes, such as firmness and crunchiness, is usually performed by sensory analysis or instrumental texture analysis. Both methodologies are destructive.
View Article and Find Full Text PDFFourier-transform near infrared spectroscopy (FT-NIR) is a technique used in the compositional and sensory analysis of foodstuffs. In this work, we have measured the main maturity parameters for grape (sugars and acids) using hundreds of intact berry samples to build models for the prediction of these parameters from berries of two very different varieties: "Victoria" and "Autumn Royal". Together with the chemical composition in terms of sugar and acidic content, we have carried out a sensory analysis on single berries.
View Article and Find Full Text PDFCurrently, the analysis of bioactive compounds is easily carried out by modern chromatographic and spectrometric techniques, but the success of the procedure still depends on the efficiency of the extraction methods. This work aimed at finding the optimal conditions for ultrasonic-assisted extraction (UAE) of phenolic antioxidants from grape skin using single-factor experimentation combined with response-surface methodology. Our extraction parameters were ethanol concentration, time and temperature.
View Article and Find Full Text PDFMetabolic profiles of 32 Negroamaro red wines were analysed using (1)H NMR spectroscopy and multivariate statistical analyses (Principal Component Analysis, PCA, and Orthogonal Partial Least Square Discriminant Analysis, OPLS-DA). Among winemaking technologies three were compared: ultrasounds (U; 12 samples), cryomaceration using dry ice (C; 12 samples) and traditional (T; 8 samples). Moreover, each vinification technology was used for grapes grown by two different soil management practices, soil tillage (ST; 16 samples) and cover crop (CC; 16 samples), and by two different training systems, monolateral (M; 16 samples) and bilateral Guyot (B; 16 samples).
View Article and Find Full Text PDFFlavonoids and stilbenes are secondary metabolites produced in plants that can play an important health-promoting role. The biosynthesis of these compounds generally increases as a response to biotic or abiotic stress; therefore, in order to achieve as high phenolic accumulation as possible, the interactive effects of storage conditions (temperature and time) and UV-C radiation on polyphenols content in postharvest Redglobe table grape variety were investigated. During a storage time longer than 48h, both cold storage (4°C) and UV-C exposure of almost 3min (2.
View Article and Find Full Text PDFA series of N-terminus benzamides of glycine-based symmetric peptides, linked to m-xylylenediamine and 3,4'-oxydianiline spacers, were prepared and tested as inhibitors of beta-amyloid peptide Abeta(1-40) aggregation in vitro. Compounds with good anti-aggregating activity were detected. Polyphenolic amides showed the highest anti-aggregating activity, with IC(50) values in the micromolar range.
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