Related Experiment Video
Updated: Apr 30, 2026
A Generalized Method for Determining Free Soluble Phenolic Acid Composition and Antioxidant Capacity of Cereals and Legumes
Published on: June 10, 2022
Intra-laboratory validation of microplate methods for total phenolic content and antioxidant activity on polyphenolic
Gloria Bobo-García1, Gabriel Davidov-Pardo, Cristina Arroqui
1Public University of Navarra, Food Technology Department, Campus Arrosadia s/n, Pamplona, 31006, Spain.
Background:
Total phenolic content (TPC) and antioxidant activity (AA) assays in microplates save resources and time, therefore they can be useful to overcome the fact that the conventional methods are time-consuming, labour intensive and use large amounts of reagents. An intra-laboratory validation of the Folin-Ciocalteu microplate method to measure TPC and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) microplate method to measure AA was performed and compared with conventional spectrophotometric methods.
Results:
To compare the TPC methods, the confidence intervals of a linear regression were used. In the range of 10-70 mg L(-1) of gallic acid equivalents (GAE), both methods were equivalent. To compare the AA methodologies, the F-test and t-test were used in a range from 220 to 320 µmol L(-1) of Trolox equivalents. Both methods had homogeneous variances, and the means were not significantively different. The limits of detection and quantification for the TPC microplate method were 0.74 and 2.24 mg L(-1) GAE and for the DPPH 12.07 and 36.58 µmol L(-1) of Trolox equivalents. The relative standard deviation of the repeatability and reproducibility for both microplate methods were ≤ 6.1%. The accuracy ranged from 88% to 100%.
Conclusion:
The microplate and the conventional methods are equals in a 95% confidence level.
