Abstract: The total phenolic contents and in vitro antioxidant activities of the pericarps of three specialty small berries in northern China (Yanshan grape, Vitis yeshanensis J.X. Chen.; red bilberry, Vaccinium vitis-idaea Linn.; black nightshade, Solanum nigrum Linn.) were comparatively analyzed. Their anthocyanin characteristics were determined by ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS). The results indicated that the total phenolic content of red bilberry was the highest, followed by Yanshan grape with black nightshade having the lowest value. But the antioxidant activity of black nightshade was significantly higher than red bilberry and Yanshan grape. A total of 61 anthocyanin compounds were identified. Yanshan grape contained the largest number of anthocyanins, and its total anthocyanin content was 17 and 52 times as high as those of red bilberry and black nightshade, respectively. The three small berry species shared common features in their anthocyanin compositions. They all contained monoglycosides and diglycosides of six anthocyanidins as well as acylated anthocyanins with the major glycosyl and acyl groups being hexosyl and p-coumaroyl, respectively. However, there were significant differences in the composition of anthocyanins among the three berry species. The major anthocyanins in Yanshan grape, red bilberry and black nightshade were malvidin (89.22%), cyanidin (93.48%) and petunidin (55.55%), respectively. The relative contents of trihydroxylated anthocyanins in Yanshan grape and black nightshade were 94.58% and 65.76% with high methylation levels (97.25% and 81.83%), respectively. The anthocyanin composition of red bilberry was dominated by diglycosided (93.73%) and non-methylated anthocyanins (94.63%). The acylation degree of anthocyanins was low (4.92% and 4.78%) in Yanshan grape and red bilberry, but high in black nightshade (81.48%). Hexose, pentose and rutinose residues were detected in red bilberry and black nightshade, while only hexose residues in Yanshan grape. Yanshan grape and black nightshade contained mainly anthocyanin diglycosides (86.91% and 85.67%), while red bilberry contained mainly anthocyanin monoglycoside (91.92%). In Yanshan grape, trace anthocyanin components were detected and tentatively identified as anthocyanin triglycosides. These results provide references for the application of Yanshan grape, red bilberry and black nightshade in fields such as food and medicine.

Key words: anthocyanin characteristics; phenolic content; antioxidant activity in vitro; small berries in Northern China