Rapid microplate high-throughput methodology for assessment of Folin-Ciocalteu reducing capacity

Talanta. 2010 Dec 15;83(2):441-7. doi: 10.1016/j.talanta.2010.09.042. Epub 2010 Oct 1.

Abstract

In the present work, a rapid and high-throughput Folin-Ciocalteu (F-C) reducing capacity assay adapted to routine/screening analysis was developed. In order to attain a fast F-C reducing kinetic reaction, the reaction conditions of the classical time-consuming F-C assay were modified and the influence of alkali and F-C reagent concentration was evaluated using gallic acid as standard. The proposed method was performed in a 96-well microplate format and it was applied to several phenolic compounds and food products (wines, beers, infusions and juices) providing F-C reducing capacity results after 3 min of reaction similar to those obtained by the time-consuming (120 min) conventional method. The additive and synergistic effect of reducing nonphenolic compounds usually found in food samples was also investigated. Ascorbic acid and ferrous sulfate provided an additive effect, while for fructose, glucose and sodium sulfite a synergistic effect was obtained. The detection limit was 0.25 mg L(-1) (as gallic acid) and the repeatability was <1.6% (n=12).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ascorbic Acid / analysis
  • Beer
  • Beverages
  • Calibration
  • Chemistry Techniques, Analytical
  • Ferrous Compounds / analysis
  • Food
  • Food Analysis / methods*
  • Food Contamination / analysis*
  • Fructose / analysis
  • Gallic Acid / analysis
  • Glucose / analysis
  • Sulfites / analysis
  • Time Factors
  • Wine

Substances

  • Ferrous Compounds
  • Sulfites
  • Fructose
  • ferrous sulfate
  • Gallic Acid
  • Glucose
  • Ascorbic Acid
  • sodium sulfite