Fig. 3.

HPLC profiles of phenolic compounds of standards and hawthorn slices detected at 280 nm. a HPLC chromatogram of phenolic standards with peaks noted as 1: gallic acid; 2: protocatechuic acid; 3: catechinic acid; 4: chlorogenic acid; 5: caffeic acid; 6: epicatechin; 7: ferulic acid; 8: rutin; 9: ellagic acid; 10: phlorizin; 11: cinnamic acid; 12: quercetin. b, c and d, HPLC chromatograms of phenolic acids in hawthorn slices dehydrated by freeze drying, hot air drying at 60 °C and microwave drying at 800 W, respectively