New Advances in the Phenolic Composition of Tiger Nut (Cyperus esculentus L.) By-Products Razola Díaz, María del Carmen Gómez Caravaca, Ana María Guerra Hernández, Eduardo Jesús García Villanova Ruiz, Belén Verardo, Vito Ultrasound-assisted extraction Phenolic compounds Antioxidant activity Chufa HPLC-ESI-TOF-MS Acknowledgments: Vito Verardo thanks the Spanish Ministry of Economy and Competitiveness (MINECO) for “Ramon y Cajal” contract (RYC-2015-18795). The authors would like to thank the Puleva company for providing “horchata” by-products. “Horchata” is a well-known Spanish beverage obtained from pressing tiger nuts. Its by-product is a potential source of sugar and fiber but also contains polyphenols; thus, it could be used as a new ingredient in the food industry. The aim of this work is to determine the phenolic compounds and compare the phenolic profile of two tiger nut by-products. A Box–Behnken design has been carried out to optimize the extraction of phenolic compounds from tiger nut by-products by ultrasound technology. The independent factors were time (min), ethanol/water (% v/v), and solvent/sample ratio (v/w). The model was validated and confirmed by ANOVA. A Protected Designation of Origin (PDO) of Valencia and a non-Protected Designation of Origin (n-PDO) tiger nut by-products were extracted under the optimal conditions and were characterized by HPLC-DADESI- TOF-MS (High Performance Liquid Chropatography coupled to a photodiode array time-offlight mass detector). Moreover, their antioxidant activities measured by three different methods (DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,20-Azinobis [3-ethylbenzothiazoline-6-sulfonic acid]- diammonium salt) and FRAP (ferric reducing antioxidant power)) were compared. A total of 45 polar compounds were identified, and the phenolic ones were quantified, some of them for the first time. PDO tiger nut by-product has been demonstrated to be richer in phenolic acids and other polyphenols and has higher antioxidant activity; meanwhile, n-PDO tiger nut by-product is richer in phenol precursors. 2022-03-14T12:21:20Z 2022-03-14T12:21:20Z 2022-01-25 info:eu-repo/semantics/article Razola-Díaz, M.d.C.; Gómez-Caravaca, A.M.; Guerra-Hernández, E.J.; Garcia-Villanova, B.; Verardo, V. New Advances in the Phenolic Composition of Tiger Nut (Cyperus esculentus L.) By-Products. Foods 2022, 11, 343. [https://doi.org/10.3390/foods11030343] http://hdl.handle.net/10481/73380 10.3390/foods11030343 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España MDPI