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The study was conducted to evaluate the optimized basis of pectinase enzyme treatment to Israel blue (Vitis
vinifera L.) grape juice through a general full factorial design and juice quality was assessed based on the ratio of Total
Soluble Solids to Titratable Acidity (TSSrr A), Total Monomeric Anthocyanin content (TAC), and antioxidant capacity.
Pectinase enzyme treatment was applied to the grape pulp to clarify grape juice and an optimization study was conducted to
determine the best level of treatment combination. Enzyme concentration (0.05 %, O. I 5 %, 0.5 %, 1.5 %, 2 %); incubation
temperature (40 <lC, 50°C) ,and incubation time (I hour, 2 hours) were used as variables. The increase of enzyme
concentration, incubation time and decrease of incubation temperature resulted in high levels of TSSrr A, TAC and
antioxidant capacity. The highest level of treatment combination was determined at (p < 0.05) level as 2 % pectinase
enzyme, 40°C incubation temperature, 2 hours' incubation time with TSSrrA 26.46, TAC 181.02 ± 4.03 mgfL and
antioxidant capacity based on OPPH radical scavenging assay as IC50 value of7.02 ± 0.34 rng of Gallic acid equivalents per
mL and ABTS radical scavenging assay as IC50 value of 0.33 ± 0.01 mg ofTrolx equivalents per mL.
