Metabolomics analysis reveals the non-enzymatic browning mechanism of green peppers (Piper nigrum L.) during the hot-air drying process

Non-enzymatic browning (NEB) reduced the colour quality of hot-air dried peppers, but the specific mechanism remains unclear. This may be related to the degradation of chlorophyll, ascorbic acid, and polyphenols. The findings revealed that the surface of pepper gradually browned during hot-air drying, with the ΔE