Validation of the phospho-molybdate method for determining total antioxidant capacity of Sorghum bicolor (L.) Moench cv. UDG 110

Abstract

In the present study, a UV spectrophotometric method for determination of the total antioxidant capacity (TOAC) in Sorghum bicolor (L.) Moench cv. UDG 110 is evaluated and validated. The validation parameters were determined according to the International Conference on Harmonisation (ICH) and Eurachem guidelines. The total antioxidant capacity was determined at 695 nm in alcoholic extract by a UV spectrophotometric method, exhibiting linearity in the range from 5 to 22.50 mg.mL⁻¹, (R²=0.9964). The limits of detection and quantification were 0.079 mg.mL^-1 and 0.263 mg.mL^-1, respectively. The evaluation of the matrix effect, demonstrated, that there is interference from substances other than analysis. The parameters evaluated showed that this method is accurate, precise, reproducible and robust since all the samples analyzed had coefficient of variation of less than 5% and no statistically significant differences between theoretical and practical concentrations were detected. The total antioxidant capacity of the Sorghum bicolor (L.) Moench cv. UDG 110 was 15.389 ± 0.710 mg of ascorbic acid per mL (mg of acid ascorbic.mL^-1). Thus, a rapid, simple, low cost and sensitive spectrophotometric method was evaluated and validated for determining the total antioxidant capacity in Sorghum bicolor (L.) Moench cv. UDG 110.