Determination of phenolic compounds and antioxidant activity in passion fruit pulp (Passiflora spp.) using a modified QuEChERS method and UHPLC-MS/MS

Abstract A new method based on the modified QuEChERS approach was developed for determination of phenolic compounds in passion fruit pulp ( Passiflora spp.) using UHPLC-MS/MS. Studies of extraction/partitioning and clean-up were carried out using different variations of the QuEChERS method (original, acetate, and citrate) and clean-up sorbents (PSA, GCB, C18 and Oasis ® HLB). The original QuEChERS method with 25 mg of C18 as dispersive cleaning sorbent showed the best results for the proposed phenolic compounds (quercetin, rutin, 4-hydroxybenzoic, chlorogenic, ferulic, vanillic, caffeic, trans- cinammic, and p -coumaric acids). Under the optimized conditions, validation presented acceptable results for linearity (r 2  ≥ 0.99), precision (RSD≤20%), recovery (73–115%), and the limits of quantification (4–80 μg/kg). The method developed was successfully applied to different species, including Passiflora edulis, Passiflora alata , and Passiflora ligularis . P. edulis was the only species that contained all target phenolic compounds, with the highest abundance of vanillic acid (426 ± 29 μg/kg) and quercetin (416 ± 6 μg/kg). In P. alata and P. ligularis species, rutin (289 ± 6 μg/kg) and caffeic acid (64 ± 2 μg/kg), respectively, were found at the highest levels. In addition, total phenolic content and antioxidant activity assays (DPPH radical and ABTS cation radical assays) correlated with the UHPLC-MS/MS analysis for all passion fruit pulps analyzed.