**3. Drying technologies**

Current drying methods have drawn increasing concerns due to low efficiency, high energy consumption, large carbon footprint and risks of causing quality and safety deterioration. As the results, the tree nut industries are under the pressure to develop more efficient and sustainable drying technologies that can preserve the quality and safety of dried products. In recent years, research works have been conducted mainly in two aspects: (1) to improve or optimize the operating conditions of the current HA drying practice; (2) to develop novel drying technologies based on thermal and non-thermal methods.
