0 mL of a 0.3 mM ethanolic DPPH solution. After an incubation period of 30 min at 25 °C, absorbance at 517 nm was recorded as Asample. A blank was also performed with the same procedure
using a solution without DPPH and the absorbance was recorded as Ablank. A control experiment (antioxidant Selleck MK-2206 absent) was performed using a solution without the dilutions of the test materials and the absorbance was recorded as Acontrol. The free radical-scavenging activity of each solution was calculated as percent inhibition, according to the following equation: equation(3) AOA(%inhibition)=100-(Asample-Ablank)×100Acontrol AOA was expressed as IC50, defined as the concentration (μg · mL−1) of the test material required to cause a 50% decrease in initial DPPH concentration. All of the measurements were performed in triplicate. The concentrated hydroalcoholic www.selleckchem.com/products/ABT-263.html extract possessed a density of 0.964 ± 0.002 g · mL−1, a solids content of 9.66 ± 0.07 (% w/w), a pH of 5.106 ± 0.005,
an alcoholic content of 38.2 ± 0.53% (v/v) and a viscosity of 5.2 ± 0.09 mPas. The levels of TPC, TFC, TTC and RAC were, respectively, 30.2 ± 0.24%, 9.13 ± 0.01%, 8.78 ± 0.1% and 10.7 ± 0.43% (w/w). Also, in the AOA assessment, the extract possessed an IC50 of 17.3 μg · mL−1. The feed extract properties provide useful information on experimental planning, since their composition, alcoholic content, solids content and viscosity may affect operational parameters of the dryer chosen. Thus, evaluation
of extract properties is essential to obtain spray-dried powders with optimised physicochemical and biological properties under maximised safety conditions. In general, for phytochemicals, drying is a crucial step since it can lead to different amorphous states for drugs and affects their stability (Araújo, Teixeira, & Freitas, 2010). The dryer type and operating conditions used in the drying process of a liquid extract play important roles in determining the properties and cost PRKD3 of a product (Souza, Schiavetto, Thomazini, & Oliveira, 2008). Hence, factors related to the drying process make the development of the phytopharmaceutical binomial formulation/process a complex task. Among the widely used drying techniques, spray drying is the most commonly used in both the food and phytopharmaceutical industries (Georgetti, Casagrande, Souza, Oliveira, & Fonseca, 2008). Spray drying presents several advantages over other drying technology, such as operational flexibility, applicability for heat sensitive materials and affordability (Wendel & Celik, 1987). SDRE properties used as quality indicators in this investigation were the contents of total polyphenols, total flavonoids, total tannins and rosmarinic acid. Additional information on process adequacy is supplied by “in vitro” antioxidant activity, which is closely related to the suitability of powder for further therapeutic use.