Effects of pretreatments on anthocyanin composition, phenolics contents and antioxidant capacities during fermentation of hawthorn (Crataegus pinnatifida) drink

• Three individual anthocyanins were found in hawthorn fruit for the first time.
• Cyanidin-3-galactoside is the main anthocyanin in Chinese hawthorn fruit.
• Heat pretreatment had good performance to increase anthocyanins and colour density.
• A significant positively correlation between anthocyanins and colour density.
• No significant effect of pretreatments on antioxidant capacity of hawthorn drink.

The effect of microwave and heat pretreatment on the content and composition of anthocyanins, phenolics, and the antioxidant capacity of hawthorn drink were studied. Nine anthocyanins were isolated by chromatographic separation from the Zirou hawthorn source and their structure identified using HPLC-DAD-ESI/MS analysis. Heat and microwave pretreatments had a significant impact on the relative contents of hawthorn anthocyanins, such as cyanidin-3-galactoside (82.9% and 76.9%, respectively) and cyanidin-3-glucoside (9.2% and 11.5%, respectively). Pretreatment had no significant effect on pH, total soluble solid or total acid. More anthocyanins remained after heat treatment than after microwaving (0.745 mg/100 mL), and were 52.4% higher than the control group after storage for 7 days. The colour density of the heat treated group was higher than the control group (24.5%) after 12 days of fermentation. The main antioxidant capacities of the hawthorn drinks came from total polyphenolics rather than total anthocyanins or total flavonoids.