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

• Reduction of phosphomolybdic‐phosphotungstic acid (Folin)  t t bl l d l i lk li l ti i reagen o a ue‐co ore comp ex n an a a ne so u on occurs n  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.

7