Simultaneous determination of flavonols and phenolic acids by HPLC-CoulArray in berries common in the Nordic diet

• HPLC coulometric array allowed determination of 9 phenolic compounds in berries.
• Phenolic profiles of bilberry, lingonberry, cloudberry and sea-buckthorn differed.
• Total phenolic content was highest in sea-buckthorn and lowest in cloudberry.

In this study we evaluated and applied an HPLC coulometric array (HPLC-CoulArray) method for simultaneous determination of flavonols and phenolic acids in bilberry, lingonberry, cloudberry and sea-buckthorn berry. Berry samples purchased from local supermarkets were freeze-dried, hydrolysed and extracted with 50% aqueous methanol containing TBHQ antioxidant and 1.2 M HCL, and analysed with HPLC-CoulArray. We found that phenolic profiles differed between berries. Quercetin was found in almost all berries, with the highest concentrations observed in lingonberry. Myricetin and isorhamnetin were only detected in bilberry and sea-buckthorn, respectively. Hydroxycinnamic acids (caffeic, ferulic, p-coumaric) were also detected in all berries, but hydroxybenzoic acids (gallic, vanillic) were not found in sea-buckthorn. Total concentration of phenolic compounds was highest in sea-buckthorn berry (270.5 mg/100 g DW), followed by bilberry (253.6 mg/100 g DW), lingonberry (219.7 mg/100 g DW) and cloudberry (121.7 mg/100 g DW).