The IC50 value is calculated as a reduction of 50% of the initial concentration of DPPH•. This reaction is used as a parameter to measure antioxidant ability to scavenge any free radicals. It is important to note that the lower the value
of IC50, the higher is the AA of the compound analyzed. The value of IC50, which is obtained using linear regression
for rosemary extract, was found to have a high coefficient of determination (R2 = 0.999). The values of IC50 and
maximum AA achieved with rosemary extract were 43.52 mg/mL and 76.40%, respectively. Rosmarinic and carnosic are the two compounds with a strong AA that are most commonly identified in rosemary. The activity of rosemary extracts is probably related to the concentration of the latter compound