Analysis of pigment composition and color dynamics of crabapple

Crabapple is an important ornamental tree species. This study analyzed 13 crabapple cultivars, examining pigment composition and content across different stages of development. According to the phenotypic and CIE Lab color system, different crabapple cultivars were clustered and analyzed, and the flower, leaf, and fruit colors of crabapple were divided into different lines. High performance liquid chromatography coupled with a diode array detector (HPLC-DAD) analysis showed that cyanidin-3-<italic>O</italic>-galactoside was the main anthocyanin in crabapple, with higher levels in the deep-red-line variety. Additionally, the petals of the purplish-red-line crabapple were found to contain higher levels of anthocyanins and carotenoids. The red-line leaves of crabapple exhibit high anthocyanin content, which gradually decreases as the leaves turn green. The ratio of carotenoids to chlorophyll was relatively high in yellow leaves. In fruits, the red-line crabapple exhibits the highest percentage of anthocyanins, which are the primary pigment substances. As the fruit changed from red to green, chlorophyll and carotenoids gradually accumulated, while anthocyanin content decreased. In yellow-line fruits, the percentage of carotenoids was relatively high. The results indicated that the color change in crabapple was driven by shifts in the relative proportions of these three pigments. Particularly, the ratio of flavonols was relatively high in the white-line crabapple petals. The ratio of flavanols to flavanones was higher in yellow leaves and fruits. This suggests that flavonols and flavanols act as co-pigments of anthocyanins, enhancing color presentation. Furthermore, crabapple is rich in phenolic compounds, including phloridzin, chlorogenic acid, hyperoside, taxifolin, and epicatechin.