AOAC Official Method 939.05 Fat Acidity—Grains Titrimetric Method
First Action 1939
Final Action
Codex-Adopted–AOAC Method*
A. Reagents
(a) Toluene–alcohol–phenolphthalein solution.—0.02%. To 1 Ltoluene add 1 L alcohol and 0.4 g phenolphthalein.
(b) Alcohol–phenolphthalein solution.—0.04%. To 1 L alcohol add 0.4 g phenolphthalein.
(c) Potassium hydroxide standard solution.—0.0178M, carbonate- free. 1 mL = 1 mg KOH.
B. Apparatus
(a) Grain mill.—Suitable for grinding small test samples.
(b) Fat extraction device.—Soxhlet or other suitable type. (Durable paper thimbles or Alundum RA-360 thimbles are suitable for
extraction.)
