An integral profile of bioactive compounds and functional properties of prickly pear (Opuntia ficus indica L.) peel with different tonalities.

Prickly pear peel is an agroindustrial by-product source of dietary fiber and bioactive compounds. Three tonalities of prickly pear cultivars: Cristalina (green), Selección 2-1-62 (yellow-orange) and Roja Lisa (red) were evaluated regarding their bioactive compounds and functional, rheological, and morphological properties. Phytochemical profile assessed by UPLC-ESI-QTOF MS^E allowed the identification of 145 compounds: sixty-eight extractable polyphenols, fifteen hydrolysable polyphenols, forty-one betalains, sixteen carotenoids, and five phytosterols. Cristalina showed the highest amount of extractable polyphenols (ferulic and benzoic acid, kaempferol 3-O-glucoside), Cristalina and Selección of hydrolysable polyphenols (gallic acid 3-O-gallate, cinnamic acid, hesperidin, myricetin 3-O-rhamnoside). Betaxanthins, carotenoids, and phytosterols were detected in all cultivars, mainly in Roja Lisa. All cultivars showed acceptable hydration properties, which was related to their porosity. Selección showed the highest elastic (G') and lower viscous (G″) behavior. These results suggest that prickly pear peels can be used as functional ingredients rich in bioactive compounds.