| Cull rabbiteye blueberries were osmotically concentrated in 55° Brix sucrose solution for 3h (O3), for 3h with ultrasound (O3+U) and for 12h (O12). These and thawed (control) samples were air dehydrated at 70°C for 10h.; Osmotic concentration increased solids gain, moisture loss and decreased acidity, thus imparting some new desirable sensory properties to berries. Increased bulk density and low rehydration ratio of pretreated berries make them ideal for use in cereal bars, ice cream or ready-to-eat snack products. Concentration also induced high loss of anthocyanins and phenolics, mainly due to leaching into the sucrose solution. Approximately 60% anthocyanins and phenolics were lost during concentration for 12h. Air dehydration further decreased anthocyanins and phenolics, with higher negative influence on anthocyanins. Antioxidant activity was lowest in preconcentrated dehydrated berries. Berries without pretreatment had highest tissue collapse and may be ideal for use in breakfast cereals. |
