Effect of Pasteurization and Sorbate Addition on Some Quality Parameters of Verjuice

Verjuice is a sour taste and refreshing traditional drink which is favorably consumed in Turkey. Some people often produce this drink for their own consumption at homes without any technological application, which might be a reason for its limited shelf life. In this study, the effect of pasteurization (15 minutes at 85°C) and potassium sorbate addition (300 mg/L) on some physicochemical (color, pH, total acidity, °Brix and turbidity) and sensory quality characteristics of verjuice samples produced from Yediveren grapes (Vitis vinifera) and stored at 2°C for 7 days were evaluated. Pasteurization and potassium sorbate addition had a significant effect on pH and turbidity values of verjuice (p<0.05) while turbidity decreased and pH increased in all groups during storage. Brix value of samples did not show any differences between groups and during storage. Lightness and redness were significantly influenced by these applications (p<0.05) while there was insignificant differences in yellowness of samples between the treatments of pasteurization and potassium sorbate addition. Aroma scores of samples ranged from 3.2 to 4.0 and the overall acceptability score was between 3.4-3.8, above the average scores. As a result, the shelf life of verjuice can be increased by pasteurization and/or by adding antimicrobial additives to the extent permitted by the legislation