Geographic Regions and Environmental Factors Influence the Nutritional and Flavor Quality of Newhall Navel Oranges

Newhall navel oranges show distinct quality differences across major producing regions in China but their specific quality characteristics remain unclear. This study compared their sensory, nutritional, and flavor properties, and investigated environmental effects and related underlying mechanisms. The results showed that Newhall navel oranges from Xinfeng, Jiangxi Province, achieved the highest overall sensory score, characterized by high sucrose content, richer aroma, and greater consumer preference. In contrast, those from Zigui, Hubei Province, exhibited higher acidity alongside greater levels of functional components (ascorbic acid, hesperidin, β-carotene). Further analysis identified (E)-2-hexenal, ethyl butanoate, octanal-D, hexanal-D, ethyl acetate, and pentan-2-one as differential aroma markers across producing regions. Hesperidin and ascorbic acid were significantly positively correlated with altitude but negatively correlated with temperature and light time, whereas sucrose content showed a negative correlatedion with altitude. Variations in the fruit quality of Newhall navel oranges were significantly correlated with climatic conditions: higher altitude and lower temperature may be associated with elevated ascorbic acid contents, while greater precipitation may correlate with reduced sugar concentrations. This study provides indirect evidence for the influence of geographical regions and environmental factors on the quality differences of Newhall navel oranges.