AOAC Official Method 931.05 Cacao Mass (Fat-Free) of Chocolate Liquor
First Action 1931
Final Action 1974
Extract 25–50 g test sample (50 g if light color, indicating low liquor) as in 930.20 (see 31.2.02), except in first aqueous extraction use 200 mL H2O for products referred to in (a) and 200 mL 1% Na2C2O4 solution (w/v) for products referred to in (b). Follow method through aqueous, alcohol, and ether extractions only.
With aid of small portions ether (45, 20, 15 mL, etc.) transfer residue resulting from ether, alcohol, and aqueous extractions to tared Al dish provided with tight-fit cover. Use small amount of acetone and policeman to transfer any material that sticks to bottle.
Evaporate liquid carefully on steam bath or hot plate, and dry residue in oven at 100°C. Cover dish, cool in desiccator, and weigh. To obtain weight dry, fat-free cacao mass, multiply weight residue by factor 1.43. To obtain weight chocolate liquor, multiply weight dry, fat-free cacao mass by factor 2.2. (This factor is based on fat content of 54% in chocolate liquors.)
References: JAOAC 14, 526, 530(1931); 24, 720(1941).
