AOAC SPDS Meeting Book March 19 2015

3/11/2015

Folin-Ciocalteu Assay • Developed by Folin and Denis 1912 to measure  tyrosine • Originally developed as an analysis for protein by  Folin in 1927 WO 4 2‐ / MO 4 2‐ + Tyrosine –OH        Blue color • Folin‐Ciocalteu (1927) added Lithium Sulfate and  Bromine to reaction mixture to prevent precipitate  formation • Adopted for phenolics in wine by Singleton 1999

Folin-Ciocalteu Assay

• PRINCIPAL

• Reduction of phosphomolybdic phosphotungstic acid (Folin) reagent ‐ to a blue‐colored complex in an alkaline solution occurs in the  presence of phenolic compounds. • The Folin ‐Ciocalteu Ciocalteu reagent reagent is not specific specific and detects all phenolic groups found in extracts including those found  in the extractable proteins.

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