Caractéristiques de pectines de marcs de raisins provenant d'essais comparatifs de vinification en rouge

Abstract

The pectins extracted in a hot acid medium (pH 1,4 at 70 °C for 4 hours) from Carignan pomace washed in hot water (75 °C, 30 mn) desceded and pipped stemmed are different according to the vinification methods. in traditional vinifica tion with crushed grapes, there are changes during the fermentation on skins (reduction in the arnount extracted and in the quality of the pectins). The pectin extract from marc of heat-treated vintage (5,4 % dry weight) contains 77 % galacturonic acid esterified to 52 %, with a jellying power of 63 ° JAKOVLIV or 31 0 SAG. Due to its poor jellying power, it is not possible to forsee and industrial recuperation from the pomace of this variety.