Extraction efficiency and validation of an HPLC method for flavonoid analysis in peppers

► An improved HPLC method was developed for the quantification of flavonoids in peppers. ► Maximum levels of flavonoids were extracted in ethanol, while myricetin was found in N-N-dimethylformamide extract. ► Efficient extraction was observed at the 1:8 ratio of sample to solvent. ► Optimum conditions for acid hydrolysis of glucosides to aglycones was 3 M HCl at 60 min at 95 °C. ► Ethanol extract had maximum phenolics and DPPH radicle scavenging activity.