S2, S3 and Table S1). The following chemicals: ascorbic acid (99% purity), cysteine (97% purity), α,α′-azodiisobutyramidine dihydrochloride (AAPH), sodium phosphate tribasic dodecahydrate (Na3PO4.12H2O), dihydrorhodamine 123 (DHR), lucigenin, luminol, sodium hypochlorite with 13% available chlorine, 30% (w/w) hydrogen peroxide solution, fluorescein sodium salt, and 2-amino-2-(hydroxymethyl)-1,3-propanediol see more (TRIS) were supplied by Sigma–Aldrich and gallic acid by Extrasynthèse (Genay, France). Ultrapure water was obtained from the Millipore system (Massachusetts, USA). Powdered GA (MW = 3.5 × 105 g/mol) was supplied by Colloids Naturels Brazil
(São Paulo, Brazil) and maltodextrin 20 DE (MW = 1000 g/mol) by Corn Products Brazil (São Paulo, Brazil). The microcapsules used in this study were the same prepared and characterized in a previously study (Faria et al., 2010). Five compounds, β-carotene, apo-8′-carotenal, apo-12′-carotenal, α-tocopherol and trolox, were microencapsulated using MD and GA as wall material, totalling 10 microcapsules. In addition, two empty microcapsules (without antioxidant), one using MD and the other using GA, were prepared. Solutions of each biopolymer (200 ml, 30% w/v) were prepared in water at 45 °C and were kept under continuous
stirring until temperature reached 30 °C. In order to obtain antioxidant solutions with similar molar concentrations, 15–63 mg ABT-263 order of each carotenoid, trolox and α-tocopherol was dissolved in a PRKD3 solvent in which each compound is highly soluble (dichloromethane for carotenoids and ethanol for α-tocopherol and trolox), and added to the polymer solution. The mixture was homogenized at 7000 rpm for 30 min and the resulting emulsion was diluted with water to obtain a 20% (w/v)
biopolymer solution. The emulsion was submitted to a spray-dryer (Lab Plant SD-04, Huddersfield, United Kingdom) under slow agitation. The microcapsules were immediately stored under N2 atmosphere and kept at −36 °C until analysis. The final core concentration (μmol/g of biopolymer) of antioxidants in the microcapsules were: trolox 2.60 and 1.88, α-tocopherol 1.55 and 2.13, β-carotene 1.39 and 1.04, apo-8′-carotenal 0.37 and 0.35, and apo-12′-carotenal 1.67 and 1.06, in GA and MD microcapsules, respectively. The residual water of the microcapsules was determined in an oven at 80 °C for 16 h (Polavarapu, Oliver, Ajlouni, & Augustin, 2011). The average and standard deviation of triplicate analysis of residual water contents (g/100 g of microcapsule) were 2.10 ± 0.07 in GA and 2.40 ± 0.06 in MD empty microcapsules. The GA microcapsules with antioxidants had very similar residual water contents (g/100 g of microcapsule): 2.30 ± 0.06 for trolox, 2.30 ± 0.09 for α-tocopherol, 2.40 ± 0.08 for β-carotene, 2.40 ± 0.