Comparative evaluation of cold plasma and microwave treatments for postharvest insect control and quality preservation in cereal grains

BACKGROUND: Postharvest cereal protection requires residue-free technologies that suppress stored-grain insects while preserving grain quality. This study directly compared atmospheric-pressure cold plasma (CP) and microwave (MW) treatments to determine which physical approach provides the more practical balance between pest control and quality retention. RESULTS: Evaluation was conducted from two complementary aspects: pest control and grain quality. Cereal grains were treated with CP at 10-20 kV or MW at 300-900 W. For pest control, both technologies produced significant intensity-dependent increases in adult mortality and reductions in grain weight loss caused by insect feeding and F₁ progeny emergence relative to untreated controls (P ≤ 0.05). CP achieved strong insect suppression at moderate voltages, whereas MW also provided effective control, particularly as power increased. For grain quality, protein and starch contents showed limited variation (< 3-4%), while enzyme activities and starch gelatinization enthalpy were more strongly affected by high-power MW than by CP. Total phenolic content and antioxidant activity increased at intermediate treatment intensities, indicating treatment-related modification of bioactive components. CONCLUSION: CP and MW are effective non-chemical disinfestation technologies, but they differ in their quality-related trade-offs. Under the tested conditions, CP offered the more favorable balance by suppressing insects while causing comparatively fewer biochemical and thermal changes, whereas MW requires careful optimization to avoid excessive quality deterioration. © 2026 Society of Chemical Industry.