The relationship between cell wall composition and extractability of anthocyanins from red grape skins
was assessed in Tempranillo grape samples harvested at three stages of ripening (pre-harvest, harvest
and over-ripening) and three different contents of soluble solids (22, 24 and 26 Brix) within each stage.
Cell wall material was isolated and analysed in order to determine cellulose, lignin, non-cellulosic polysaccharides,
protein, total polyphenols index and the degree of esterification of pectins. Results showed
the influence of ripeness degree and contents of soluble solids on cell wall composition. Furthermore,
principal components analysis was applied to the obtained data set in order to establish relationships
between cell wall composition and extractability of anthocyanins. Total insoluble material exhibits the
biggest opposition to anthocyanin extraction, while the highest amounts of cellulose, rhamnogalacturonans-
II and polyphenols were positively correlated with anthocyanin extraction. Moreover, multiple linear
regression was performed to assess the influence of the cell wall composition on the extraction of anthocyanin
compounds. A model connecting cell wall composition and anthocyanin extractabilities was built,
explaining 96.2% of the observed variability.