Impact of Ultraviolet radiation and 1-methylcyclopropane treatments on maintain quality and storability of Iceberg lettuce head during cold storage.

This study was carried out on head Lettuce (Lactuca sativa L. cv Iceberg) during two seasons, in 2020 and 2021, to study the effect of exposed head lettuce to ultraviolet radiation (UV-C) doses (200 and 250 nm for 5 min) and 1-Methylcyclopropene sheet (1-MCP) 1.5 and 5% alone and combination between them beside untreated control on maintaining quality and storability of lettuce heads during storage at 0°C and 95% relative humidity for 20 days. Results showed that all postharvest treatments-maintained head lettuce quality compared to untreated control during storage; however, exposed head lettuce to ultraviolet radiation 250 nm + 5% 1-Methylcyclopropene for 5 minutes and 200 nm + 5% 1-Methylcyclopropene for 5 minutes, were the most effective in reducing the weight loss percentage, decay score and total microbial count and incidence of discoloration. Also, maintained general appearance, ascorbic acid and total phenolic compound content. Furthermore, delaying polyphenol oxidase activity compared with other treatments.
Lettuce heads treated with ultraviolet radiation 250 nm + 5% 1-Methylcyclopropene showed the best appearance and maintaining postharvest quality and didn’t exhibit any changes in their appearance and gave excellent appearance at the end of storage period (20 days at 0 °C) while 200 nm + 5% 1-Methylcyclopropene treatment gave good appearance at the same period.