Effects of corona discharge plasma pretreatment on the drying performance and quality retention of Cornus officinalis

This study investigates the effects of corona discharge plasma (CDP) pretreatment on the hot-air drying performance and quality retention of Cornus officinalis fresh fruit. By integrating drying kinetics modeling, microstructural characterization, heat and mass transfer theory, and comprehensive quality assessment, the underlying mechanisms by which CDP enhances drying efficiency and product quality were systematically elucidated. The results demonstrated that CDP significantly increased the effective moisture diffusivity and accelerated the drying rate, with the Page model providing the best fit for drying behavior (R² > 0.99). Scanning electron microscopy revealed that CDP facilitated the formation of microporous surface structures, thereby enhancing heat and mass transfer capabilities. Furthermore, CDP markedly inhibited the activities of polyphenol oxidase (PPO) and peroxidase (POD), mitigating enzymatic browning. Notably, treatments at 9 kV for 3 minutes and 10 kV for 3 minutes significantly elevated total phenolic content (TPC) and total flavonoid content (TFC). Principal component analysis indicated that group G6 (10 kV, 3 min) achieved the highest comprehensive score (1.902), identifying it as the optimal condition for processing Cornus officinalis. These findings provide both theoretical underpinnings and practical insights for the efficient application of plasma technology in the processing of traditional Chinese medicinal materials.