Widely targeted metabolomics to analyze the effect of polyvinyl alcohol/pullulan/ZnO-Nps composite film on postharvest storage of Allium mongolicum regel.

In this study, a composite film (CF) made of polyvinyl alcohol, pullulan, and ZnO nanoparticles was prepared by solution casting. The CF were applied to the postharvest preservation of Allium mongolicum Regel. Widely targeted metabolomics analysis of A. mongolicum Regel by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to investigate the mechanism of action of active substances in A. mongolicum Regel during CF-treated storage process. Analysis of the results showed that 1534 metabolites were present in CF-treated A. mongolicum Regel, of which 175 metabolites were significantly different. KEGG analysis showed that the differential metabolites were mainly involved in metabolic pathways, secondary metabolite biosynthesis, including the biosynthetic metabolism of compounds such as flavonoids and phenolic acids and alkaloids. The changes in these secondary metabolites further affected key metabolic pathways such as flavonoid biosynthesis, phenylalanine metabolism, carbon fixation in photosynthesis and glycolysis. These results help to explain the preservation mechanism of A. mongolicum Regel during the storage period and provide an important theoretical basis for the preservation of A. mongolicum Regel composite film packaging in the future.