Effect of Four Drying Methods on the Quality of Intermediate Moisture Lowbush Blueberries

ABSTRACT Lowbush blueberries have been processed by freeze dry, forced air, vacuum oven, and micro‐convection methods to a moisture content of 16‐25%. The drying effect on the product quality was evaluated. There were no significant differences in vitamin A and niacin retention except freeze dried berries had higher vitamin C retention. No significant differences occurred in retention of mineral content except higher sodium and lower magnesium were found in the micro‐convection and freeze dry methods, respectively. Freeze dried and vacuum dried blueberries had higher soluble solids retention and were darker and redder than forced air or micro‐convection dried berries. Freeze dried berries were found to have highest rehydration ratio and lowest bulk density.