THE EFFECT OF PECTOLYTIC ENZYME TREATMENTS ON RED GRAPES MASH OF VRANEC ON GRAPE JUICE YIELDS

Laboratory and industrial trials were conducted to evaluate the effect of pectolytic enzyme treatments on red grape mash of Vranec on grape juice yields. The red grape Vranec for laboratory trials were taken from private winery “Imako vino” Stip (Macedonia) and trials were conducted in their laboratory. The red grape Vranec for industrial trials were taken from private winery “Tristo” Veles (Macedonia) and trials were conducted in their winery. The grapes were weighed, destemmed, crushed and divided in 5 liters plastic reservoirs for laboratory trials, and for industrial trials were placed in a stainless steel fermentor (4t.). All treatments were performed in doublecate. Red grape mash made from Vranec were macerated for 6 hours at 18 to 20oC with addition of one commercial pectolytic enzymepreparation (Vinozym Vintage FCE, Rohapect VR-C and Trenolin Rot DF). After addition of SO2 (50ppm) and yeast (Saccharomyces cerevisiae) NEUTRE SC (Lallemand, 2009)(200 mg/kg grape), maceration time of 5 days (~25 oC) was applied in order to study the effect of macerating enzymes on grape juice yields. After the maceration, the pomace was removed, in the obtained 4 different variations. Pectolytic enzyme preparation was not added to control trial. All treatments were performed in duplicate. Results of laboratory and industrial trials from our experiments, gives increased on free run juice yields by 4.85%-6.35% compared with non-treated mash of control trials.