Differential Analysis of Anthocyanins in Red and Yellow Hawthorn (Crataegus pinnatifida) Peel Based on Ultra-High Performance Liquid Chromatography-Electrospray Ionization Tandem Mass Spectrometry

Anthocyanins constitute the primary pigment components in hawthorn (Crataegus pinnatifida) peel, yet their specific composition and concentration profiles remain poorly characterized. This study employed ultra-performance liquid chromatography–electrospray ionization–tandem mass spectrometry (UPLC-ESI-MS/MS)-based metabolomics to systematically compare anthocyanin profiles between red-peel (CPR) and yellow-peel (CPY) hawthorn cultivars. Our analysis identified 26 anthocyanin metabolites in CPR and 24 in CPY, with cyanidin-3-O-galactoside and cyanidin-3-O-arabinoside being the predominant compounds in both. Multivariate analysis revealed seven significantly differential metabolites, including cyanidin-3-O-galactoside, cyanidin-3-O-arabinoside, pelargonidin-3-O-galactoside, pelargonidin-3-O-glucoside, pelargonidin-3-O-arabinoside, and peonidin-3-O-galactoside. Notably, all the differential metabolites exhibited reductions in CPY compared to CPR. Chromatic analysis demonstrated that CPR possessed highly significantly lower hue angle values (hab) than CPY (47.7093 ± 4.1706, 83.6427 ± 1.4604, p < 0.01), showing strong negative correlations with key anthocyanins. These findings enhance the scientific understanding of anthocyanin biosynthesis in hawthorn peel and provide a certain reference for the development and utilization of anthocyanins in hawthorn peel.