Phenolic profiles and antioxidant activities of Saskatchewan (Canada) bred haskap (Lonicera caerulea) berries

Abstract

Phenolic extracts from five Saskatoon, Saskatchewan, bred and grown haskap berry varieties (Aurora, Blizzard, Honey Bee, Indigo Gem, and Tundra) were characterized via liquid chromatography with photodiode array detection (HPLC-PDA) and mass spectrometry (HPLC-MS/MS). Tundra had the highest phenolic content (727.0 mg/100 g FW) while Indigo Gem had the highest anthocyanin content (447.8 mg/100 g FW). HPLC-MS/MS identified two previously unreported anthocyanins (Tundra variety): delphinidin-sambubioside and a peonidin-pentoside. Fruit extracts were fractionated to produce an anthocyanin rich (40% ethanol) and flavanol/flavonol rich (100% ethanol) fraction. This process affords the ability to isolate/concentrate specific subclasses for nutraceutical applications. High in vitro radical scavenging was observed for all haskap phenolic extracts. An extract from the Tundra variety delayed borage oil oxidation more effectively than commercial antioxidants (BHT and Rosamox). These results show the high phenolic content of these haskaps along with their capacity for radical scavenging/delaying lipid oxidation, indicating potential commercial value.