title: Effect of growing zone and vintage on the prediction of extractable flavanols in winegrape seeds by a FT-NIR method.
abstract: The feasibility of Fourier transform-near-infrared (FT-NIR) spectroscopy for predicting the extractable content of phenolic compounds directly in intact grape seeds was evaluated. NIR calibration models were based on the correlation of spectral data with the phenolic composition determined by reference chemical methods for 40 grape samples. The vintage effect was studied evidencing that the predictive accuracy improved only for spectrophotometric indices when samples of two years were simultaneously considered. The statistical parameters of calibration showed that the models developed are sufficiently robust for quantitative purposes of total flavonoids, proanthocyanidins, low molecular weight flavanols, catechin, epicatechin, procyanidin B1, and galloylation percentage (standard prediction error (SEP%) < 15, predictive index (RPIQ) > 3.0), but could be also useful for screening of absorbance at 280 nm, total polymers, epicatechin gallate, and procyanidin B2 (SEP% < 15, RPIQ = 2.7-2.9). Although a calibration model is required for each geographical origin, the results suggest that FT-NIR spectroscopy is a promising analytical technique in this field.
authors.affiliation: Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università degli Studi di Torino , Via Leonardo da Vinci 44, 10095 Grugliasco, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Torchio
authors.forename: Susana
authors.initials: S
authors.lastname: Río Segade
authors.forename: Simone
authors.initials: S
authors.lastname: Giacosa
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Gerbi
authors.forename: Luca
authors.initials: L
authors.lastname: Rolle
mesh_terms: D010636:Phenols / Q000032:analysis* / Q000302:isolation & purification; D010936:Plant Extracts / Q000032:analysis / Q000302:isolation & purification; D012639:Seeds / Q000737:chemistry* / Q000254:growth & development; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D027843:Vitis / Q000737:chemistry* / Q000254:growth & development
chemical_list: D010636:Phenols; D010936:Plant Extracts