Polysaccharide composition of Monastrell red wines from four different Spanish terroirs: effect of wine-making techniques.

Monastrell wines made from grapes grown in four different Spanish "terroirs" (Cañada Judío, Albatana, Bullas, and Montealegre) were studied. Different wine-making techniques were also used, including different refrigeration techniques (prefermentative cold maceration and dry ice addition) and the addition of two different enzymes (ß-galactosidase and commercial pectinase enzyme). The results pointed to significant differences in the Monastrell wine polysaccharide fractions according to the geographical origin of the grapes. The Rhamnogalacturonan II (RG-II) concentration was 2-fold higher in the Montealegre terroir than in the Bullas terroir. The use of enzymes also modified the polysaccharide content of the wines. RG-II levels were higher in the wines from three terroirs when commercial enzymes were added. The arabinose/galactose ratio of one of the wines was modified by the use of enzymes during wine-making, and some prefermentative cold maceration samples showed high values for several polysaccharides. This study shows the great importance of the "terroir effect" in the polysaccharide composition of wines.