title: Dynamic flow-through approach to evaluate readily bioaccessible antioxidants in solid food samples.
abstract: Release of bioactive compounds from food matrices is regarded as the first step towards their human bioavailability. The objective of this work was the implementation of an affordable and robust flow-through device for expedient dynamic leaching experiments aiming at the assessment of readily bioaccessible antioxidant compounds in solid food commodities. A simple configuration is proposed using commercially available devices containing regenerated cellulose filters placed in polypropylene holders to entrap the solid sample, featuring a disposable, single use extraction chamber. The kinetic extraction profile of fast leachable antioxidants from different food matrices was evaluated using the ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)) assay, fitting a first-order reaction model for readily bioaccessible compounds (R>0.9). The leaching rate constant values associated to the fast leachable antioxidant compounds were 0.060-0.446min-1and 0.105-0.210min-1for water and ethanol/water (1:1, v/v) applied as extractants, respectively. Furthermore, no statistically significant differences were found between the estimated values of bioaccessible antioxidant compounds by the kinetic model and the values attained using conventional batch-wise extraction methodology, ranging from 3.37 to 60.3 µmol of Trolox ((±)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid) per g of sample. Extension of the method using U. S. Pharmacopeia surrogate biological media (stomach (pH 1.2) and intestinal (pH 7.5) fluids without enzymes) to NIST-1570a spinach leaves provided gastrointestinal compartment-dependent kinetic leaching rates (0.120 and 0.198min-1, respectively) and total antioxidant content (45.5 and 52.5µmol of Trolox per g of sample, respectively).
authors.affiliation: UCIBIO, REQUIMTE, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, R Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Maia
authors.affiliation: UCIBIO, REQUIMTE, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, R Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
authors.forename: Tânia R P
authors.initials: TRP
authors.lastname: Soares
authors.affiliation: UCIBIO, REQUIMTE, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, R Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
authors.forename: Ana I P
authors.initials: AIP
authors.lastname: Mota
authors.affiliation: FI-TRACE Group, Department of Chemistry, University of Balearic Islands, Carretera de Valldemossa km 7.5, 07122 Palma de Mallorca, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Rosende
authors.affiliation: UCIBIO, REQUIMTE, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, R Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
authors.forename: Luís M
authors.initials: LM
authors.lastname: Magalhães
authors.affiliation: FI-TRACE Group, Department of Chemistry, University of Balearic Islands, Carretera de Valldemossa km 7.5, 07122 Palma de Mallorca, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Miró
authors.affiliation: UCIBIO, REQUIMTE, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, R Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal. Electronic address: msegundo@ff.up.pt.
authors.forename: Marcela A
authors.initials: MA
authors.lastname: Segundo
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification* / Q000493:pharmacokinetics; D001682:Biological Availability; D005591:Chemical Fractionation / Q000295:instrumentation / Q000379:methods*; D005504:Food Analysis; D012997:Solvents / Q000737:chemistry; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000975:Antioxidants; D012997:Solvents; D014867:Water
keywords: Antioxidant capacity; Bioaccessibility; Bioactive compounds; Dynamic extraction; Solid sample