Effects of different pretreatments on physicochemical properties and phenolic compounds of hawthorn wine

The physicochemical properties, organic acid, and phenolic profiles of hawthorn wines prepared by different pretreatments were analyzed. It was found that fermentation together with smashed seeds was favorable for ethanol production, while thermal maceration, addition of pectinase and amyloglucosidase significantly increased the levels of sugar-free extract, residual sugar, total phenolics, flavonoids, and most individual phenolic comounds, showing beneficial effects on improving nutritive value of hawthorn wine. Addition of pectinase and amyloglucosidase caused an increase of methanol content by 34.88% and 26.97%, respectively, while thermal maceration decrease the methanol content by 36.20%. Addition of amyloglucosidase yielded the highest contents of procyanidins as well as flavanols, while thermal maceration and addition of pectinase were favorable for improving phenolic acid level. All the pretreatments significantly increased the contents of succinic acid and malic acid in the final wines, among which thermal maceration and addition of pectinase yielded the highest content of succinic acid and malic acid respectively.