Physicochemical and functional properties of the undervalued fruits of cactus Cylindropuntia imbricate (“xoconostle”) and antioxidant potential

Abstract

The acidic and not very fleshy fruits from Xoconostles (Xo) cacti are undervalued fruits. However, inhabitants of semi-arid regions consume these fruits that may also have a high nutritional value and natural antioxidants because of their content of dietary fiber (DF) and polyphenols. Currently, there is a lack of knowledge about the nutritional and functional properties of these types of fruits. The study aimed to evaluate the phytochemical profile, physicochemical, functional (water-holding, oil holding, and swelling capacities), and antioxidant properties of different sections (E: epicarp ; M-E: mesocarp-endocarp) of wild Cylindropuntia imbricata (Haw.) F.M. Knuth (Xoconostle) fruits. Results showed that Xo fruits have the highest concentration of condensed tannins (CT) and hydrolyzable tannins (HT) in E. The phenolic acids (PAs) identified in the fruits were caffeoyl tartaric acid , 5-5′-dehydrodiferulic acid, 1,2,2′-trisinepoylgentiobiose, catechin , sinensetine, dihydroquercetin, quercetin , delphinidin , and 5,3′,4′-trihydroxy3-methoxy-6:7-methylenedioxyflavone4′-O-glucuronide, with a total of 15 acidic polyphenols identified in Xo. The antioxidant capacity of polyphenols showed that the 1:16 and 1:12 m/v ratios in E and ME had the highest radical scavenging activity for DPPH (1,1-diphenyl-2-picrylhydrazyl) (41 and 72 mg TE/g); ABTS (2,2′-azinobis (3-ethylbenzothiozoline-6-sulfonic acid)) (317 and 406 mg TE/g) and FRAP (ferric reducing antioxidant power) (568 and 481 mg TE/g), respectively. Positive correlations were perceived between polyphenols and DPPH, ABTS, FRAP. Therefore, these results confirm the potential of wild Xo fruits ( C. imbricata ) as a source of natural antioxidants, DF, and functional properties that could be useful in the food, pharmaceutical, and cosmeceutical industry. • The undervalued fruits of Xoconostle (Xo) have a high fiber content and antioxidant properties. • The different genotypes and ultrasound conditions determine the chemical composition. • The cultivation of the wild fruits of Cylindropuntia imbricata (Haw.) F.M. Knuth may be revalued by the producers. • The 1:16 and 1:12 m/v ratio provided the highest acidic polyphenols content, obtained by UMAE. • The Xo fruits contained a high concentration of CT and HT, that exhibits excellent antioxidant activity.