The antioxidant activity of teas measured by the FRAP method adapted to the FIA system: optimising the conditions using the response surface methodology.
Food Chem
; 138(1): 574-80, 2013 May 01.
Article
in En
| MEDLINE
| ID: mdl-23265526
ABSTRACT
This study proposes a FRAP assay adapted to FIA system with a merging zones configuration. The FIA system conditions were optimised with the response surface methodology using the central composite rotatable design. The optimisation parameters studied were the carrier flow rate, the lengths of the sample and reagent loops, and reactor length. The conditions selected in accordance with the results were carrier flow rate of 1.00 ml/min, length of the loops 18.2 cm and length of the reaction coil 210.1 cm. The detection and quantification limits were, respectively, 28.6 and 86.8 µmol/l Fe(2+), and the precision was 1.27%. The proposed method had an analytical frequency of 30 samples/h and about 95% less volume of FRAP reagent was consumed. The FRAP assay adapted to the FIA system under the optimised conditions was utilised to determine the antioxidant activity of tea samples.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Tea
/
Ferric Compounds
/
Chemistry Techniques, Analytical
/
Flow Injection Analysis
/
Antioxidants
Type of study:
Evaluation_studies
Language:
En
Journal:
Food Chem
Year:
2013
Document type:
Article
Affiliation country:
Brazil