Bioactive compounds in Amelanchier alnifolia L. berries

Introduction. The dark blue berries of the Saskatoon (Amelanchier alnifolia L.) shrub are powerhouse of health-promoting substances. Rich in flavonoids, phenolic compounds, and anthocyanins, these berries offer significant antioxidant and anti-inflammatory benefits, and may also help regulate blood sugar levels. Their diverse bioactive profile suggests they could be a valuable addition to a healthy dieta and potentially have therapeutic applications [1]. Material and methods. In July 2023, Saskatoon berries were harvested from the Rietavas region (55.67282,22.11187). To evaluate preservation impacts, the berries were subjected to three methods: freeze-drying, air-drying at 40˚C, and frezing at -18˚C. Subsequently, extraction of bioactive compounds was performed using an ultrasonic bath. Variables tested included extraction temperatures (20-25˚C and 50-55˚C), ethanol concentrations (30%, 50% and 70%), and extraction durations (10,30 and 40 minutes), with a 1:20 berry to ethanol ratio. To determine antioxidant activity, spectrophotometric DPPH and ABTS methods were applied. To determine the amount of phenolic compounds, the spectrophotometric Folic-Ciocalteu method was used. To determine the amount of flavonoids, a reaction with aluminum (III) chloride and hexamethylenetetramine solutions was used. Results and their discussion. After examining Amelanchier alnifolia L. berries, the total phenolic content was found to vary from 3,37 mg GAE/g to 18,69 mg GAE/g. The highest phenolic content of 18,69 mg/g was found in freeze-dried Saskatoon berries. The lowest phenolic content of 3,37 mg/g was found in dried Saskatoon berries. The highest flavonoid content of 13,71 RE/g was found in freezedried berries. The lowest flavonoid content of 5,45 RE/g was found in dried berries. The change in free radical scavening ranged from 156,06 ɥmol/g to 182,24 ɥmol/g. The strongest antioxidant activity of 182,24 ɥmol/g was found in freeze-dried berries. The lowest antioxidant activity of 156,06 ɥmol/g was observed in dried berries. Antioxidant activity ranged from 56% to 65%. The strongest antioxidant activity was found in freeze-dried Saskatoon berries – 65%, and the lowest antioxidant activity – 56% in frozen Saskatoon berries.