Secondary aroma compounds in fresh grape marc distillates as a result of variety and corresponding production technology.

In order to investigate secondary aroma compound composition of fresh grape marc distillates as a result of variety and production technology, 30 samples (6 varieties x 5 samples) were produced. White grape marcs from Malvazija istarska, Chardonnay and Muscat Blanc were obtained as by-products in standard white wine production, while red grape marcs from Teran and Cabernet Sauvignon were obtained after standard red wine production procedures. Marcs from red grape variety Muskat ruža porecki were obtained during production of rose wines. Fermented marcs were distilled using a traditional copper alembic. Obtained distillates were subjected to GC/MS and GC/FID analysis. Malvazija istarska distillates exhibited exceptionally high methanol content. Distillates from white grape varieties were found to be characterized by higher C6-alcohols and 1-propanol concentrations, while red grape distillates contained higher amounts of the majority of alcohols, acids, and esters. In Muskat ruža distillates intermediate concentrations of many important aroma compounds were found. It was concluded that differences in production technology parameters, depending on the variety, resulted in differences in secondary aroma profiles, most evident between distillates from white and red varieties. These findings were confirmed applying SLDA which resulted in 100% correct classification of distillates according to variety and corresponding production technology.