Résumé
Aleatico is an Italian red winegrape variety traditionally used partially dehydrated to produce Passito wines. The aim of this research is to assess the effect of two different off-vine withering techniques (natural sun-exposed: SUN, and controlled temperature and humidity conditions: CTR) on grapes physicochemical modifications, focusing on mechanical properties, phenolic profile, and cell-wall polysaccharide structures. The composition and extractability of polyphenols were studied before and after the two withering processes, differentiating the tissues (skin, pulp, seeds). A stronger effect on cell-wall polysaccharides composition pectin was highlighted by chemical and immunochemical approaches in SUN skins at the level of pectin chains and de-esterification, affecting grapes mechanical properties, especially for skin rigidity (