Comprehensive Characterization and Quantification of Antioxidant Compounds in Finger Lime (Citrus australasica L.) by HPLC-QTof-MS and UPLC-MS/MS Aznar, Ramón Rodríguez Pérez, Celia Australian finger limes Phenolic compounds Flavonoids Limonoids Antioxidant activity HPLC Tandem mass spectrometry Celia Rodriguez-Perez thanks the University of Granada for the PPJIA2019-04 project. Authors also acknowledge Teagasc for the access to the LC-MS/MS facilities and the support to this work through the Teagasc Walsh Fellowships Program (2016038). Australian finger limes (Citrus australasica L.), an unusual citrus due to its unique pulp with a caviar-like appearance, has reached the global market as a promising source of bioactive compounds that promote health. This research was, therefore, performed to shed light on the bioactivity and composition of different parts of Citrus australasica L. (peel and pulp). Initial ultrasound-assisted extraction using MeOH:H2O (80:20, v/v) was carried out. After that, four fractions (hexane, ethyl acetate, butanol and water) were generated through liquid-liquid partitioning, and the total phenolic content (TPC) and antioxidant activity were evaluated using the Folin-Ciocalteu and the ferric reducing antioxidant power (FRAP) assays, respectively. The ethyl acetate fraction in the peel, which presented the highest values of TPC and antioxidant activity, was characterized using high-performance liquid chromatography coupled to quadrupole time-of-flight (HPLC-QTof) mass spectrometry. Fifteen compounds were identified, of which seven were characterized for the first time in this matrix. Moreover, ten phenolic compounds were quantified using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The major compounds in the sample were citric acid, pyrogallol, caffeic acid, coumarin, rutin, naringin, 2-coumaric acid, didymin, naringenin and isorhamnetin, which were found in a range from 2.7 to 8106.7 mu g/g sample dry weight. Finally, the results presented in this novel work confirmed that the peel by-product of C. australasica L. is a potential source of bioactive compounds and could result in a positive outcome for the food, cosmetics and pharmaceutical industries. 2022-03-25T09:23:34Z 2022-03-25T09:23:34Z 2022-02-07 info:eu-repo/semantics/article Aznar, R.; Rodríguez-Pérez, C.; Rai, D.K. Comprehensive Characterization and Quantification of Antioxidant Compounds in Finger Lime (Citrus australasica L.) by HPLC-QTof-MS and UPLC-MS/MS. Appl. Sci. 2022, 12, 1712. [https://doi.org/10.3390/app12031712] http://hdl.handle.net/10481/73742 10.3390/app12031712 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España MDPI