doi:10.1016/j.lwt.2021.112158engKaanin-Boudraa G.Brahmi F.Wrona M.Nerín C.Moudache M.Mouhoubi K.Madani K.Boulekbache-Makhlouf L.Response surface methodology and UPLC-QTOF-MSE analysis of phenolic compounds from grapefruit (Citrus¿ paradisi) by-products as novel ingredients for new antioxidant packagingART-2021-125784The present work reports an experimental study on the optimization of phenolic compounds extraction from Citrus ¿ paradisi peels and the development of active packaging. Response surface methodology (RSM) was applied to investigate the effect of microwave-assisted extraction (MAE) for the recovery of total phenolic compounds (TPC). The TPC in the optimized extract were 31.10 mg gallic acid equivalent/100 g of dry weight (mg GAE/100 g dw) with strong antioxidant capacity. The bioactive compounds in the optimized extract were determined by ultrahigh performance liquid chromatography coupled to quadrupole time-of-flight with high energy mass spectrometry (UPLC-QTOF-MSE). Forty-five compounds were detected and qualified. The optimized extract obtained by MAE was used as an active antioxidant in multilayer food packaging films. The multilayer low-density polyethylene (LDPE)/polyethylene terephthalate (PET) containing 10% of MAE optimized extract provided the most antioxidant power acting as a free radical scavenger. © 2021 Elsevier Ltd2021http://zaguan.unizar.es/record/15096610.1016/j.lwt.2021.112158http://zaguan.unizar.es/record/150966oai:zaguan.unizar.es:150966info:eu-repo/grantAgreement/ES/DGA-FSE/T53-20RLWT-FOOD SCIENCE AND TECHNOLOGY 151 (2021), 112158 [11 pp.]by-nc-ndhttps://creativecommons.org/licenses/by-nc-nd/4.0/deed.esinfo:eu-repo/semantics/openAccess