Preparation of poly (vinyl alcohol)/microcrystalline cellulose composite film and its application for the preservation of Lanzhou lily ( Lilium davidii var. unicolor )

In this research, microcrystalline celluloses (MCC) extracted from Jerusalem artichoke stalk, Sweet sorghum stalk, Distiller’s grains, and Chinese herb residue were respectively incorporated with poly (vinyl alcohol) (PVA) to prepare the biodegradable composite films for the preservation of Lanzhou lily. The effects of different MCC sources and contents on the physicochemical properties of composite films were investigated. The crosslinking of four kinds of obtained MCCs with PVA could significantly improve the thermal stability and UV–Vis barrier property of PVA film. When the amount of MCC was 5%, the decrease of PVA/CHRMCC composite film was the largest among the four films, which was 30.97%. In the second stage of thermal decomposition, the decomposition temperature of MCC/PVA composite film is lower than that of pure PVA film (233.12 °C). A majority of PVA/MCC composite films have good mechanical properties and flat surface, especially the composite films fabricated with 5% MCC, which was elected for subsequent preservation of lily bulbs. Lily bulbs packaged with PVA/MCC composite films demonstrated enhanced preservation efficacy. This is attributed to the film’s ability to slow down respiration and decrease enzyme activity. Notably, by the end of the 12th day of storage, the PPO activity in lily bulbs wrapped with MCC/PVA was approximately 29% less than that of the control group. This can be ascribed to the film’s capability in inhibiting gas exchange and the accumulation of malondialdehyde. Moreover, PVA/CHRMCC composite film was recommend based on subordinate function method.