Phenolics and antioxidant activity of Saskatoon berry (Amelanchier alnifolia) pomace extract

Saskatoon berries (Amelanchier alnifolia Nutt.) have significantly higher levels of anthocyanins (ACY) among berries with potential health benefits. The pomace is a by-product of juice extracted from berries and is a potential source of inexpensive polyphenols. The objectives of this study were to extract the maximum amount of total phenolics from saskatoon pomace, to determine the antioxidant activity, and to identify individual phenolic components. Pomace extracts showed high content of total phenolics, total ACY, and total flavonoids of 43.3, 2.8, and 10.3 g/kg of dried weight (DW) of pomace. A high oxygen radical absorbing capacity value of 119.4 μmol Trolox equivalents/g DW and free radical scavenging activity of pomace extract (200 ppm, 86.8%) were observed. Five major ACY, two flavonols, and three chlorogenic acids were identified and quantified in pomace extracts. This study shows that saskatoon berries pomace rich in antioxidant phenolics could be extracted by "green" solvents (water and ethanol) and used as suitable food product applications.