Effect of pectolytic enzymes on the composition of white grape musts and wines

The effect of two commercial pectolytic enzymes was investigated on different compounds of the musts and on the fermentation process. Two different enzyme treatments (grape pomace and must) were compared to a non-enzymatic treatment. Settling and clarification processes were improved in the enzyme-treated musts. Generally, the enzyme-treated musts had higher titratable acidity and total polyphenols, and lower total pectin content than non-enzyme treated must. During the fermentation of musts, the development of reducing sugars, titratable acidity and total polyphenols was similar in all cases. The wines made from enzyme-treated musts had a lower amount of total pectins and higher titratable acidity, but their acetic acid values were lower than non-enzyme treated wines. The methanol content was higher in the enzyme-treated wines than in the non-enzyme treated wines, but was lower than the legal limit (150 mg/L).