Improving Disinfection and Packaging Strategies for the Effective Preservation of Welsh Onion (Allium fistulosum L.)

This study aimed to improve postharvest preservation strategies for Welsh onion ( Allium fistulosum L.) by optimizing disinfection techniques and packaging methods. Conducted in two phases, the first involved disinfection using gamma irradiation (1, 3, and 5 kGy) and cold plasma (15, 20, and 25 kV for 5, 10, and 15 minutes). In the second phase, four gas-barrier nanocomposite films were tested under ambient and vacuum-sealed storage for 4, 8, and 12 months. Volatile compounds was analyzed via gas chromatography (GC and GC/MS). Cold plasma was more effective than gamma irradiation in preserving key postharvest quality parameters. The highest phenolic content and antioxidant activity were found in samples treated with cold plasma at 20 and 25 kV for 5 minutes. Nonetheless, all packaging treatments experienced declines in total phenolics, essential oil yield, and L* color values over time. Major volatile compounds in the essential oil included dipropyl disulfide, dipropyl trisulfide, dimethyl trisulfide, diallyl disulfide, and d-limonene. This study introduces an innovative approach that combines cold plasma treatment with nanocomposite-based packaging to extend shelf life and preserve the functional and sensory qualities of fresh vegetables during long-term storage. These findings offer valuable insights for postharvest management of leafy vegetables like Welsh onion.