Quality Changes of Blackcurrant Nectar Under Different Storage Conditions
Grażyna Jaworska
Department of Fruit, Vegetable and Mushroom Technology, University of Agriculture in Krakow, Poland
Krystyna Pogoń
Department of Fruit, Vegetable and Mushroom Technology, University of Agriculture in Krakow, Poland
Marek Klimek
Department of Fruit, Vegetable and Mushroom Technology, University of Agriculture in Krakow, Poland
Ewelina Gwóźdź
Department of Fruit, Vegetable and Mushroom Technology, University of Agriculture in Krakow, Poland
Keywords: Fruits, Beverages, Stability, Antioxidant activity, Colour.
Abstract
Blackcurrant nectars were stored for 12 months: in cooling conditions (6-8°C); in ambient conditions (18-22°C); in thermostatic chamber (25-31°C); in thermostatic chamber (39-40°C).
Time and storage conditions had no effect on dry matter content, total solids, ash and total acidity. During 6 months of storage total phenols content decreased by 0-13% and then increased by 12-26%. After 12 months of storage level of vitamin C in blackcurrant nectars fell by 70% in the nectar stored in cooling conditions and by 75-87% in the remaining beverages. A continuous decline in antioxidant activity (against ABTS and DPPH) was observed throughout the storage period; the changes observed did not depend on storage conditions. An increase in colour parameters (L*, a*, b*, c*, h*) has been observed. Changes in the quality of nectar stored for 3 months in thermostatic chamber were greater than those noted in nectar stored for 12 months in cooling conditions.