基于LC-MS技术分析褚橙商品成熟与生理成熟时果实内在品质的差异OACSTPCD

Chu orange(Citrus sinensis L.)is one of most valuable fruit in the Yunnan Province for its high economic and nutritional value.To investigate the effects of changes in mic-molecule secondary metabolites dur-ing the physiological maturation period on the intrinsic quality of the fruit,a widely targeted metabolomic analysis of fresh pulps was conducted using liquid chromatography-mass spectrometry(LC-MS)on Chu orange fruits at the commercial ripeness(PR)and physiological ripeness(R)stages.The final differential compounds were ana-lyzed using partial least squares discriminant analysis(PLS-DA),volcano map analysis,and hierarchical cluster analysis(HCA).A total of 822 metabolites were detected in commercially mature and physiologically mature or-ange fruits.In total,43 differential metabolites belonging to 31 kinds were identified,including amino acids and the derivatives(6 kinds),flavonoids(4 kinds),sugars and the derivatives(2 kinds),lipids(1 kind),nucleic acids and the derivatives(1 kind),phenols(3 kinds),alkaloids(8 kinds),aromatic compounds(1 kind),terpenoids(2 kinds),spices(2 kinds),and organic acids and the derivatives(1 kinds).The contents of 29 compounds were up-regulated,while the contents of 14 compounds were significantly decreased.Differential metabolites were en-riched into five crucial pathways,including phenylalanine metabolism,fructose and mannose metabolism,amino sugar and nucleotide sugar metabolism,valine,leucine and isoleuaocine biosynthesis,and starch and sucrose metabolism,which might affect the quality of Chu orange.The changes in the abundance of metabolites such as sugars,flavonoids,alkaloids,amino acids,phenols and organic acids in Chu orange resulted in changes in fruit taste after physiological maturity.This study provides some basic data for metabolic regulation mechanism and a comprehensive utilization of intrinsic quality formation of Chu orange fruit.