A novel method for evaluating flavanols in grape seeds by near infrared hyperspectral imaging.
Chemical composition of seeds changes during grape ripening and this affects the sensory properties of wine. In order to control the features of wines, the condition of seeds is becoming an important factor for deciding the moment of harvesting by winemakers. Sensory analysis is not easy to carry out and chemical analysis needs lengthy procedures, reagents, and it is destructive and time-consuming. In the present work, near infrared hyperspectral imaging has been used to determine flavanols in seeds of red (cv. Tempranillo) and white (cv. Zalema) grapes (Vitis vinifera L.). As reference measurements, the flavanol content was estimated using the p-dimethylaminocinnamaldehyde (DMACA) method. Not only total flavanol content was evaluated but also the quantity of flavanols that would be extracted into the wine during winemaking. A like-wine model solution was used for this purpose. Calibrations were performed by partial least squares regression and they provide coefficients of determination R(2)=0.73 for total flavanol content and R(2)=0.85 for predicting flavanols extracted with model solution. Values up to R(2)=0.88 were reached when cultivars were considered individually.
Food Colour & Quality Lab., Dept. Nutrition & Food Science, Facultad de Farmacia, Universidad de Sevilla, 41012-Sevilla, Spain.
Francisco J
FJ
Rodríguez-Pulido
Food Colour & Quality Lab., Dept. Nutrition & Food Science, Facultad de Farmacia, Universidad de Sevilla, 41012-Sevilla, Spain.
José Miguel
JM
Hernández-Hierro
Food Colour & Quality Lab., Dept. Nutrition & Food Science, Facultad de Farmacia, Universidad de Sevilla, 41012-Sevilla, Spain.
Julio
J
Nogales-Bueno
Food Colour & Quality Lab., Dept. Nutrition & Food Science, Facultad de Farmacia, Universidad de Sevilla, 41012-Sevilla, Spain.
Belén
B
Gordillo
Food Colour & Quality Lab., Dept. Nutrition & Food Science, Facultad de Farmacia, Universidad de Sevilla, 41012-Sevilla, Spain.
M Lourdes
ML
González-Miret
Food Colour & Quality Lab., Dept. Nutrition & Food Science, Facultad de Farmacia, Universidad de Sevilla, 41012-Sevilla, Spain. Electronic address: heredia@us.es.
Francisco J
FJ
Heredia
D044950:Flavanones / Q000032:analysis*; D010936:Plant Extracts / Q000032:analysis*; D012639:Seeds / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared / Q000379:methods; D027843:Vitis / Q000737:chemistry*
D044950:Flavanones; D010936:Plant Extracts
Chemometrics; Flavanols; Grape seeds; Hyperspectral imaging; Near infrared; Vitis vinifera L