Effects of N₂-LED Integrated Cold Storage on Postharvest Quality Retention of Sichuan Pepper

This study examines the effects of nitrogen (N₂), cold storage (CS), yellow LED irradiation, and their combined application (N₂+LED+CS) on the quality of Sichuan pepper during storage. While individual treatments have been reported, their combined effect remains unexplored; this approach simultaneously targets temperature, oxygen, and light. The research focused on how these methods influence qualitative characteristics, including the preservation of OH-α-sanshool (the numbing component), total polyphenol content (TPC), total flavonoid content (TFC), and flavor compounds over a 60-day storage period. Preliminary screening of individual storage factors (temperatures: 5, 10, 20, 40 °C; O₂ levels: 0%, 10%, 20%, 40%; and LED colors: white, red, blue, yellow) showed that 5 °C and 0% O₂ significantly slowed degradation of TPC, TFC, and flavor compounds, while yellow LED notably preserved OH-α-sanshool. The combined N₂+LED+CS approach was particularly effective, reducing losses in TPC and TFC by 46.88% and 57.00%, respectively, compared to the control group. Additionally, OH-α-sanshool levels under N₂+LED+CS conditions were maintained at 19.04 mg/g, representing a 115.38% reduction in loss. The study concludes that the N₂+LED+CS method is a simple and efficient strategy that does not rely on chemical preservatives, offering a potentially sustainable approach to Sichuan pepper preservation.