赣南脐橙生长过程中的主要滋味物质的变化

Changes of main taste substances during the growth of Gannan navel oranges

采用靶向代谢组学技术,对赣南脐橙生长过程中的主要糖、有机酸和氨基酸进行准确定量分析。结果表明,赣南脐橙不同生长阶段之间生长生理变化及相关代谢物特征差异明显,单果重量逐渐增加,果形指数略有下降。随着果实成熟糖类物质大量积累,其中蔗糖含量最高,果糖和葡萄糖含量相当。大部分有机酸在果实成熟过程中逐渐降解,总有机酸含量下降,其中柠檬酸占主导地位,占6种主要有机酸总和的90%以上。天冬氨酸是主要的氨基酸,蛋氨酸、精氨酸和脯氨酸呈现上调趋势,其余氨基酸整体呈下调趋势。糖酸比先升高后降低,最后达到最佳比例范围,表明果实在生长过程中不断改善其滋味品质。相关性分析揭示赣南脐橙生长过程中的风味特征物质包括果糖、葡萄糖、奎宁酸、亮氨酸、丙氨酸、谷氨酸和甘氨酸。构建代谢网络并结合热图分析,发现赣南脐橙果肉的滋味相关代谢物的表达在不同的生长阶段差异明显,客观反映了生长期对脐橙生长代谢和滋味品质的影响。除了研究主要滋味物质不同生长阶段代谢变化,还进行了风味评价和相关代谢物代谢网络的构建,加深对赣南脐橙营养成分和滋味有效成分特性的认识,有利于功能性脐橙产品的开发,并对优化脐橙育种以提高果实品质提供重要参考。

Targeted metabolomics technology was used to accurately quantify the major sugars,organic acids and amino acids during the growth of Gannan navel orange.The results revealed significant variations in growth physiology and related metabolite characteristics at different growth stages.The weight of single fruit gradually increased and the fruit shape index slightly decreased.As the fruit matured,sugars accumulated in large quantities,with sucrose having the highest content,and fructose and glucose having comparable contents.Most of the organic acids were gradually degraded during fruit ripening,and the total organic acid content decreased,with citric acid dominating,accounting for more than 90% of the total of the six major organic acids.Aspartic acid was the main amino acid,while methionine,arginine and proline showed an upward trend,and the rest of the amino acids as a whole exhibited a downward trend.The sugar-acid ratio first increased and then decreased,finally reached the optimal ratio range,indicating that the fruit continuously improved its flavour quality during the growth process.Correlation analysis revealed that the flavour profile substances during the growth process of Gannan navel orange included fructose,glucose,quinic acid,leucine,alanine,glutamic acid and glycine.The metabolic network was constructed and the heat map analysis was conducted,showing significant variation in the expression of flavor-related metabolites in the flesh of Gannan navel orange at different growth stages,reflecting the influence of the growth period on growth metabolism and flavor quality.Besides studying the metabolic changes of the main flavour substances at different growth stages,this paper also carried out flavour evaluation and constructed metabolic networks of related metabolites,deepening the understanding of the characteristics of the nutrient and flavour effective components of Gannan navel oranges.This research is beneficial for developing functional navel orange products and capable of providing an important reference for navel orange breeding to improve the quality of the fruits.