Influence of pressing on aroma and phenolic profiles of Malvazija istarska and Chardonnay grape musts

During harvest 2006, the influence of grape mash pressing on aroma and phenolic composition of Malvazija istarska and Chardonnay grape musts, both originating from the western vine growing areas of Istrain peninsola, was studied. Pressing was performed using a pneumatic press of 500 L capacity. The samples of must fractions were collected at pressures of 0.5, 1.0 and 1.5 bar, while free-run must was used as a control. In all obtained musts following physico-chemical parameters were determined: sugars, pH, total acidity, varietal aroma compound concentrations, hydroxycinnamic and hydroxybenzoic acid, and flavan-3-ols concentrations, total phenols content, and antioxidant activity. On the basis of the results obtained, it was concluded that pressing significantly influence the chemical composition of analyzed musts.