10 ± 0.06 for apo-12′-carotenal. The residual water contents in g/100 g of MD microcapsules were also similar: 2.30 ± 0.13 for trolox, 2.20 ± 0.07 for α-tocopherol, 2.00 ± 0.07 for β-carotene, 2.30 ± 0.11 for apo-8′-carotenal and 2.40 ± 0.04 for apo-12′-carotenal. The composition of the antioxidant compounds in the microcapsules was determined in order to verify composition changes after microencapsulation. In order to release the carotenoids, around 0.20 g of the MD microcapsules
were dispersed http://www.selleckchem.com/products/SB-203580.html in 5 ml of water, whilst 0.10 g of the GA ones were dispersed in 5 ml of water:methanol (2:3, v/v). The carotenoids were extracted exhaustively with dichloromethane from the microcapsule solution; the organic phases were recovered in a separation funnel and the residual water was removed with anhydrous Na2SO4. α-Tocopherol and trolox were extracted straight from 0.20 g of the microcapsule powder with 5 ml of ethanol by sonication (1 min), vortexing
(5 min) and centrifugation (Beckman Coulter, California, USA) at 20000 g during 5 min. Afterward, the residual water of the supernatant was removed with anhydrous Na2SO4 and filtered. The solvent was removed under vacuum in a rotary evaporator (T < 35 °C). The dry extracts were redissolved, carotenoids in methanol:methyl tert-butyl-ether (1:1, v/v), α-tocopherol in methanol and trolox in methanol:water:formic acid (70:29.5:0.5, v/v/v), and analyzed by HPLC–DAD–MS/MS. These Protease Inhibitor Library results are presented Selleckchem Rapamycin at Supplementary Figs. S2, S3 and Table S1. The experiments were conducted immediately after the preparation of fresh microcapsules aqueous solutions to avoid their slow collapse in solution since in our previous study, these microcapsules presented a half-life of 17 ± 3 h and around 60 h for the complete release of pyrene molecules (Faria et al., 2010). The assays were carried out in a microplate reader (Synergy Mx, BioTek, Vermont, USA) for fluorescence, UV/vis and luminescence measurements, equipped with a thermostat set at 37 °C and dual reagent dispenser. Two control assays were conducted in all
microplates, one of them to verify the interaction among the probe and the microcapsules, without radical generator or reactive species addition and the other one as quality analytical control (positive control), adding a compound with known capacity to scavenge the specific reactive species. No interaction between the probes and the microcapsules was observed and the maximum variation in the response of the positive controls during the assays was ⩽10%. Each ROS and RNS scavenging assay corresponds to two independent experiments, performed in duplicate. Except for peroxyl radical scavenging capacity, the results are presented as percent of inhibition, IC50 or IC20 values, calculated by non-linear regression analysis using the GraphPad Prism 5 software. The increase in scavenging capacity due to addition of antioxidant molecules was calculated by Eq. (1).