Phenolic profile and antioxidant activity of honeysuckle (Lonicera caerulea) berry pomace

Effective processing of fruit and berry pomace may generate valuable functional ingredients for developing food products with higher amounts of different dietary polyphenols and other health-beneficial phytochemicals. Honeysuckle berries are rich in vitamins, polyphenolic compounds (anthocyanins, iridoids, phenolic acids and flavonoids), saponins and sugars. The aim of this study was to investigate the phenolic composition of honeysuckle berry pomace extracts by traditional and advanced extraction methods. Triacylglycrerols, anthocyanins and other phenolic compounds, iridoids, organic acids, monosaccharides were performed by ultraperformance chromatography (UPLC) coupled with a time-of-flight mass spectrophotometer (Q-TOF). Saponin content was determined by the UV spectrophotometric method. The main identified triacylglycerols were 1-linolyl-2-linolyl-3-linolylglycerol (LLL), 1-oleoyl-2-linolyl-3-linolylglycerol, 1-oleoyl-2-oleoyl-3-linolylglycerol, 1-palmitoyl-2-linolyl-3-linolylglycerol, and 1-palmitoyl-2-linolyl-3-oleoylglycerol. For instance, the main triacylglycerol LLL varied from 33.84% to 59.10% in EtOH and H2O extracts. Honeysuckle pomace presented six anthocyanins; cyanidin3-glucoside was identified as the main anthocyanin. Monosaccharides such as fructose and glucose were predominant sugars in all honeysuckle berries extracts. The main organic acids, iridoids and phenolics were citric acid, chlorogenic acid, and quercetin-3-rutinoside. Loganic acid, loganic acid-7-O-pentoside, alpigenoside, quercetin hexoside, kaempferol/luteolin hexoside, and luteolin-3-rutinoside were identified in the obtained extracts. The quantitative determination of citric acid showed an interval from 107mg to 171 mg gE−1 extract. In general, honeysuckle is a good source of dietary antioxidants and may be a promising functional ingredient for increasing nutritive value and also may be used as a functional powder for the manufacture of cosmetics, food supplements and etc.