AOAC 2019 First Action Methods

AOAC Official Method 2019.06 Quantification Soluble Proanthocyanidins in Cranberry Foods and Dietary Supplements 4-(Dimethylamino)cinnamaldehyde (DMAC) Assay First Action 2019

(Applicable to the determination of soluble proanthocyanidins in foods and dietary supplements containing cranberry fiber powder, enriched cranberry extract powder, cranberry juice extract, or cranberry proanthocyanidins liquid.) Caution : Refer to the Material Safety Data Sheets for all chemicals prior to use. This method includes the use of hydrochloric acid. Use all appropriate personal protective equipment and follow good laboratory practices. A. Principle

The 4-(dimethylamino)cinnamaldehyde (DMAC) assay is used for the quantification of soluble PAC (1, 2).

B. Sample Materials

( a ) Cranberry fiber powder. –Low concentration solid: Obtained commercially from a raw ingredient manufacturer. ( b ) Cranberry extract powder (soluble powder enriched in PAC). –High concentration solid: Obtained commercially from a raw ingredient manufacturer. ( c ) Cranberry juice concentrate. –Low concentration liquid: Obtained commercially from a raw ingredient manufacturer. ( d ) Cranberry PAC liquid. –30% (w/v); High concentration liquid: Produced at UW laboratory. C. Apparatus (a) Volumetric flasks. –Used for reagent and standard preparations. (b) UV-Vis microplate reader. –Capable of measuring kinetic reactions at 640 nm in a 96-well plate. (c) 96-well plate. (d) Ultrasonic bath. (e) Vortex mixer. (f) Balance, analytical. –Minimum weighing capacity of 0.01 mg. (g) Bottle-top dispenser. –Capable of dispensing 15 mL.