Ultrasound-assisted extraction and antioxidant activity of polyphenolic compounds from three different fruit form of Lonicera caerulea L.

This study compared different forms of Lonicera caerulea L. fruit (fresh berries, dried berries, freeze-dried powder) to assess their suitability for storage and transport by analyzing their polyphenolic compounds content via ultrasound-assisted extraction. Optimal conditions were identified for extracting phenolics, flavonoids, and anthocyanins with orthogonal experiment, and antioxidant activities of the polyphenolic compounds were detected by free radical scavenging activity against DPPH and ABTS. The optimal extraction conditions were identified as follows: for total phenolics, 60% ethanol, 30 min, and 300 W; for flavonoids, 80% ethanol, a 60:1 liquid to solid ratio, and 500 W; for anthocyanins, 40 min at 40 °C with 80% acidified ethanol. The polyphenolic compounds in dried berries showed stronger free radical scavenging abilities with the increase of compounds concentration, which was close to or more than that of ascorbic acid. Above all, dried berries were the most suitable form for guiding the harvest, storage, processing and high value-added product development of its Fruit, which provides practical basis for industrial application and functional product development of Lonicera caerulea L.