title: Use of near infrared hyperspectral tools for the screening of extractable polyphenols in red grape skins.
abstract: Hyperspectral images of intact grapes were recorded at harvest time using a near infrared hyperspectral imaging system (900-1700 nm). Spectral data have been correlated with red grape skin extractable polyphenols (total phenolic, anthocyanins and flavanols) by modified partial least squares regression (MPLS) using a number of spectral pretreatments. The obtained results (coefficient of determination (RSQ) and standard error of prediction (SEP), respectively) for the developed models were: 0.82 and 0.92 mg g(-1) of grape skin for extractable total phenolic content, 0.79 and 0.63 mg g(-1) of grape skin for extractable anthocyanin content, 0.82 and 0.45 mg g(-1) of grape skin for extractable flavanol content. The obtained results present a good potential for a fast and reasonably inexpensive screening of the extractable polyphenolic compounds in intact grapes. Moreover, the heterogeneity of extractable polyphenols within the ripeness stage has been also evaluated using the proposed method.
authors.affiliation: Food Colour and Quality Laboratory, Department of Nutrition and Food Science, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: Nogales-Bueno
authors.affiliation: Food Colour and Quality Laboratory, Department of Nutrition and Food Science, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain.
authors.forename: Berta
authors.initials: B
authors.lastname: Baca-Bocanegra
authors.affiliation: Food Colour and Quality Laboratory, Department of Nutrition and Food Science, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain.
authors.forename: Francisco José
authors.initials: FJ
authors.lastname: Rodríguez-Pulido
authors.affiliation: Food Colour and Quality Laboratory, Department of Nutrition and Food Science, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain.
authors.forename: Francisco José
authors.initials: FJ
authors.lastname: Heredia
authors.affiliation: Food Colour and Quality Laboratory, Department of Nutrition and Food Science, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain. Electronic address: jmhhierro@us.es.
authors.forename: José Miguel
authors.initials: JM
authors.lastname: Hernández-Hierro
mesh_terms: D000872:Anthocyanins / Q000737:chemistry; D005419:Flavonoids / Q000737:chemistry; D016018:Least-Squares Analysis; D059808:Polyphenols / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared; D027843:Vitis / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D005419:Flavonoids; D059808:Polyphenols
keywords: Anthocyanins; Chemometrics; Extractable polyphenols; Flavanols; Grapes; Near infrared hyperspectral imaging