Abstract: This study employed a mixture of hydroxypropyl methylcellulose (HPMC) as the film-forming matrix and sodium ligninsulfonate (Ls) as the CO2 sorbent to fabricate an edible film for modified atmosphere packaging of fruits. The effect of Ls content (3%, 6%, and 9% of HPMC in dry mass) on the film’s structure and gas permeability as well as on the respiration regulation and quality preservation of Shatang mandarin was investigated. The results demonstrated that Ls was compatible with HPMC and concurrently enhanced the strength and toughness of the composite film. Its CO2 and O2 barrier properties increased with Ls addition, both increasing by over 50% at 9% Ls addition. A high CO2 and low O2 atmosphere was formed inside Shatang mandarin wrapped with the composite film, reducing the respiration rate of fruit. The composite film with 6% Ls decreased the respiration rate, mass loss, and decay incidence by 32.5%, 11.0% and 48.2% compared with the untreated control group, respectively. Additionally, the composite film maintained the fruit hardness and the contents of soluble solids, titratable acid, and vitamin C in the fruit flesh, indicating the best quality preservation. In conclusion, the HPMC/Ls composite film possesses controllable gas permeability and enables controlled atmosphere preservation through appropriate inhibition of fruit respiration. It offers advantages such as simplicity, ease of use and environmental friendliness, and holds great potential for application in fruit preservation.

Key words: hydroxypropyl methylcellulose; sodium ligninsulfonate; edible film; Shatang mandarin; modified atmosphere