Comparative study on metabolites, nutrients, and antioxidant capacity of endosperm in Gymnocladus chinensis, Gleditsia sinensis, and Gleditsia japonica var. delavayi.

'Zaojiaomi' is a traditional food derived from Gleditsia sinensis or Gleditsia japonica var. delavayi endosperm. However, metabolite profile of Gymnocladus chinensis endosperm and its comparison to the aforementioned species remains understudied. This research employed a UPLC-MS based metabolomics approach to investigate and compare metabolite composition of G. chinensis endosperm with that of G. sinensis and G. japonica endosperm. A total of 1177 metabolites were identified, with 579 and 577 differentially abundant metabolites found between G. chinensis vs. G. japonica and G. chinensis vs. G. sinensis, respectively. They were mainly enriched in pathways related to flavonoid biosynthesis, suggesting potential for enhanced antioxidant activity, compared to G. japonica and G. sinensis. Additionally, G. chinensis endosperm was found to be rich in L-arginine, L-aspartic acid, and zinc elements, which have various health benefits. These findings provide valuable insights into metabolic composition of G. chinensis endosperm and its potential as a functional food source.