Widely targeted metabolomic analysis of active compounds at different maturity stages of ‘Hupingzao’ jujube

Understanding the variation in active ingredients of ‘Hupingzao’ during maturity is important for the development of functional jujube products and the efficient use of ‘Hupingzao’ resources. We investigated the metabolic variation of active ingredients of ‘Hupingzao’ at different maturity stages (S1–S5) using widely targeted metabolites. In total, 406 compounds were detected, 191 were annotated by the KEGG database, and 40 active compounds showed significant differences, which may be related to 18 core metabolic pathways. Except for some nucleosides and carbohydrates, the content of most active compounds increased and then decreased with jujube fruit growth. ‘Hupingzao’ was richer in nucleosides and organic acids. The ideal times for the development of eight different active compounds (nucleosides, carbohydrates, organic acids, amino acids, lipids, alcohol, vitamins, and terpenoids) were at seven different maturity stages (S5, S5, S3, S4, S2, S3, and S1), respectively. Widely targeted metabolomics analysis was shown to be a good method to determine the composition of functional jujube compounds. The results of this study serve as a new theoretical reference for functional food experts to promote functional jujube products of ‘Hupingzao’.