'Barton' Pecan Drying: Interaction Between Microwave, High Temperature and Storage Time on the Nut Color and Volatile Compounds Profile

Due to the limitations of conventional drying systems in pecan postharvest management, alternative technologies capable of accelerating moisture reduction while preserving kernel quality are required. Therefore, the present study aimed to assess the impact of drying pecan nuts using microwave radiation (100 W), hot airflow (40°C), and ambient temperature airflow, followed by storage for 6 months at 20°C, on color parameters and volatile compound profile of 'Barton' pecans. Microwave drying led to a significant reduction in drying time and proved to be 256.8 times and 15.7 times more efficient than drying with ambient airflow and at 40°C, respectively. Moreover, microwave drying demonstrated superior preservation of yellow color after 6 months of storage at 20°C compared to pecans dried using airflow. Variations were observed in the abundance of volatile compounds in the dried pecans among the three conditions. Pecans dried using microwave radiation exhibited higher levels of volatiles derived from amino acid degradation (2-methylbutanol, 2-methylpropanol, and 3-methylbutanol), while volatiles stemming from lipid degradation were more abundant in pecans dried using airflow. Our findings demonstrate that microwave drying (100 W) is a technically viable alternative for rapid moisture reduction while limiting the accumulation of volatile aldehydes associated with lipid oxidation in pecan kernels during prolonged storage.