Effect of drying method on drying time and physico-chemical properties of dried rabbiteye blueberries

Individually quick frozen (IQF) rabbiteye blueberry cultivars Brightwell and Powderblue were dried in an air-impingement dryer at 85 °C and 107 °C using two different configurations. The effect of cultivar, pick, grade, drying temperature and method on drying time and physico-chemical properties of dried blueberries were determined. Forced air dryer and a fluidized bed dryer were used as controls. Drying times were about 50% longer at 85 °C compared to 107 °C for all drying methods. Among the drying methods; fluidized bed dryer was fastest followed by air-impingement dryer(s) and forced air dryer to achieve a final water activity of 0.55 ± 0.05. Cultivar, drying method and their interaction with drying temperature shown significant effect (P ≤ 0.05) on drying times. Several tested variables and their specific interactions also showed significant effect on bulk density, color, texture and composition of dried blueberries. Impingement drying showed promise as an alternative to fluidized bed dryer to dry IQF rabbiteye blueberries.

► Drying method, temperature and cultivar showed significant effect on drying time. ► Modified impingement reduced the drying time at 85 °C compared to impingement dryer. ► Texture of the dried blueberries influenced by the cultivar and pick time. ► Cultivar, pick, grade, drying temperature showed significant effect on composition. ► Color and bulk density were influenced by pick, grade, drying method & temperature.