Green coffee beans of Coffea arabica and Coffea canephora accessions from different geographical origin (Brazil, Colombia, Ethiopia, Honduras, Kenya, Mexico, Peru, Uganda and Vietnam) were extracted and the extracts analysed by HPLC-ESI-MS/MS for the identification and quantification of chlorogenic acids and caffeine content. Principal component and cluster analyses were used to identify chemical patterns separating the different species and accessions based on their geographical origin. C. canephora showed always a higher caffeine content with respect to C. arabica, whereas the C. arabica accessions from Kenya showed a higher chlorogenic acids and a lower caffeine content. The antioxidant capacity of green coffee extracts was assayed by the reducing power and DPPH assays. The antioxidant capacity correlated with the chlorogenic acids content. The resultsshow that the C. arabica from Kenya possesses the highest chlorogenic acids/caffeine ratio and, among the C. arabica accessions, the highest antioxidant capacity. Therefore, the C. arabica from Kenya is the most suitable green coffee source for nutraceutical applications because of its high antioxidant capacity and low caffeine content.

Highlights•Bilberry antioxidant compounds are selectively extracted by subcritical CO2.•Anthocyanins, flavonoids, phenolics and proanthocyanidins show antioxidant properties.•Cyanidin-3-O-glucoside and cyanidin-3-O-arabinoside are selectively extracted. AbstractAnthocyanins and other phenolic compounds of bilberry (Vaccinium myrtillus) are known for their antioxidant properties. Supercritical (SC) and subcritical (SubC) CO2 extractions have been used to improve extraction and selectivity of plant bioactive compounds. Bilberry was extracted by SC CO2 followed by SubC CO2 with 10% v/v ethanol as co-solvent. Total phenolic compounds, anthocyanins and proanthocyanidins were quantified and chemically characterized by HPLC-DAD-ESI-MS/MS. Antioxidant activity was tested by reducing power assay, free radical scavenging activity (DPPH) and ABTS radical cation assay. SubC CO2 selectively extracted cyanidin-3-Oglucoside and cyanidin-3-O-arabinoside. Delphinidin-3-O-glucoside, ellagic acid pentoside, feruloyl hexoside and several quercetin glycosides were also extracted. SubC CO2 extracts showed a high antioxidant activity [DPPH IC50 = 102.66 (±2.64); ABTS IC50 = 8.49 (±0.41) and reducing power activity IC50 = 10.30 (±0.10)]. SubC-CO2 extraction of bilberry is an efficient method to recover selectively compounds with a high antioxidant activity and a high potential for pharmacological applications. Graphical abstractSupercritical and subcritical CO2 extraction of bilberry allowed to recover selectively cyanidin-3-Oglucoside and other compounds with a high antioxidant activity. Abbreviations