Metabolite Variations during the First Weeks of Growth of Immature and by Untargeted Liquid Chromatography-Mass Spectrometry/Mass Spectrometry Metabolomics.

Immature citruses are an important resource for the pharmaceutical industry due to their high levels of metabolites with health benefits. In this study, we used untargeted liquid chromatography-mass spectrometry (LC-MS) metabolomics to investigate the changes associated with fruit size in immature citrus fruits in the first weeks of growth. Three orange cultivars ( 'Navel', 'Valencia', and 'Valencia Late') and a mandarin ( 'Fremont') were separated into eight fruit sizes, extracted, and analyzed. Statistical analyses revealed a distinct separation between the mandarin and the oranges based on 56 metabolites, with an additional separation between the 'Navel' orange and the 'Valencia' and 'Valencia Late' oranges based on 21 metabolites. Then, metabolites that evolved significantly with fruit size growth were identified, including 40 up-regulated and 31 down-regulated metabolites. This study provides new insights into the metabolite modifications of immature and in the first weeks of growth and emphasizes the significance of including early sampled fruits in citrus maturation studies.