Volatile Organic Compounds In Sweet Passito Wines As Markers Of Grape Dehydration/Withering/Drying Process

Twenty-four sweet Passito wines from Italy were analyzed through gas chromatography-mass spectrom-etry. Apart from the vinification process , which was unknown , the Passito wines differed in the water loss technique used , the grape variety , and the latitude/orography of provenance. Two volatile organic compound markers , ethyl acetate and furfural , were identified , characterizing wines produced with the technique of Vin Santo , wines from sun drying , and wines from late harvest. These compounds were found at low concentrations in wines produced with grapes dehydrated in "fruttaio" (closed facility) , under controlled or uncontrolled conditions. Wines from Muscat varieties had more esters and terpenes , but the wines produced from grapes dehydrated in fruttaio in North Italy , particularly those grown on high mountains , had more than Muscat wines produced in South Italy or using sun drying. Primary and secondary aroma compounds are reported for each wine. A controlled environment during dehydration, preferably at low temperature, better preserves the aroma of grapes for wine production.