Francisco J. Heredia

TL;DR: Changes on turbidity, phenolic composition and color showed that animal and plant proteins differed in their clarifying efficiency and ability to interact with colorless phenolics and anthocyanins, depending on the age of wine, with important consequences on color quality and stability.

TL;DR: In the case of white grape seeds, it was proved that merged images were better to discriminate between varieties than the single CIELAB or spectral images.

Abstract: The colour of 123 Amontillado wines from “Condado de Huelva” Designation of Origin, made from white grapes of the Zalema variety and slowly aged in different types of wood casks, has been studied. Colour differences due to different materials from which the casks were manufactured (Spanish and American oak wood) have been appreciated. Tristimulus methods have been applied following the recommendations of the International Commission on Illumination (CIE). Colour parameters ( $$a_{10}^*$$ , $$b_{10}^*$$ , $$L_{10}^*$$ , $$C_{{\rm ab}10}^*$$ , h ab10) from CIELAB space and saturation ( $$s_{{\rm uv}10}^*$$ ) from CIELUV space have been used for calculus. The results indicated differences for lightness and saturation, which allows one to establish the areas of predominant colour for the characterisation of the colour of this type of wines. Multivariate statistical analysis demonstrated that different groups of selected variables give similar results, meaning that the wines aged in American oak barrels and Spanish oak barrels show significant (p<0.05) differences in colour variables. Three supervised learning methods, classification tree, linear discriminant analysis and back-propagation artificial neural network, have been applied for distinguishing between classes.

TL;DR: In this article, a method for determining phenolic compounds of wood and its extractability to the hydroalcoholic medium is proposed in an in situ, non-destructive, and fast way.

TL;DR: In this paper, the authors compared the reliability of the Lovibond method versus the more rigid recent CIE methods, including the Munsell system, with the simplified methods proposed by the L'office Internationale de la Vigne et du Vin (OIV).