Dynamic flow-through approach to evaluate readily bioaccessible antioxidants in solid food samples

作者：Maia Miguel A; Soares Tania R P; Mota Ana I P; Rosende Maria; Magalhaes Luis M; Miro Manuel; Segundo Marcela A^*

来源：Talanta, 2017, 166: 162-168.

DOI：10.1016/j.talanta.2017.01.040

• Bioaccessibility
• Solid sample
• Antioxidant capacity
• Bioactive compounds
• Dynamic extraction

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 0.060-0.446 min(-1) and 0.105-0.210 min(-1) for 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 mu mol 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 0.198 min(-1), respectively) and total antioxidant content (45.5 and 52.5 mu mnol of Trolox per g of sample, respectively).

• 出版日期2017-5-1