Phenolic composition and cell-based biological activities of ten coloured potato peels (Solanum tuberosum L.)

•Coloured potato peels are rich sources of phenolic compounds.•Pelargonidin, peonidin and malvidin were the main anthocyanin compounds detected.•Caffeic and quinic acid were the most abundant non-anthocyanin phenolic compounds.•All hydroethanolic extracts presented antioxidant and antitumor activities.•No toxic effect to non-tumor cell lines was detected up to 304 μg/mL of extract. The present study provides an in-depth characterisation of the non-anthocyanin and anthocyanin phenolic compounds of potato peels from ten coloured potato varieties. Furthermore, the underexplored bioactive potential (antioxidant, cytotoxic and anti-inflammatory capacities) of the studied peels is comprehensively analysed. Among non-anthocyanin phenolics, caffeic and a caffeoylquinic acid were found in the highest concentrations in all samples, which also showed the presence of O-glycosylated flavonol derivatives and polyamine derivatives. Acylated anthocyanins were identified in red and purple varieties, being pelargonidin, peonidin, and malvidin the most prominent aglycones. All samples revealed antioxidant and antitumor activities, and no toxic effect. The extract of the Rosemary variety presented the best antioxidant and antitumor outcomes and was the only sample to reveal anti-inflammatory activity. These results are valuable for the food-industry by adding value to an important bio-residue, particularly concerning its potential as natural ingredients in novel food and pharmaceutical formulations.