20-01.01 Egg Solids—Digitonin Cholesterol Method
This method measures the percent cholesterol (sterol) in pasta, egg noodles, and similar products.
20-10.01 Egg Solids in Pasta Products
This method estimates the egg solids content of egg pasta by determining the cholesterol content of unsaponifiable material found under Method 30-40. If egg-free products or material containing less than 0.23% unsaponifiable material are used, add 10 mg cholesterol before analysis and correct results accordingly. The added cholesterol should have a melting point of not less than 147°, and its purity should be checked by submitting 20 mg to determination below.
20-20.01 Determination of Isoflavones in Soy and Selected Foods Containing Soy by Extraction, Saponification, and Liquid Chromatography
Test samples are extracted at 65° for 2 hr in 80% methanol solution and then saponified at ambient temperature with sodium hydroxide. The extracts are acidified, filtered, and diluted with water to 50% methanol. They are then centrifuged to clarify and are analyzed by liquid chromatography (LC). Isoflavone glucosides and aglucons are separated using a C-18 reverse-phase column with a methanol-water mobile phase and are measured by UV detection at 260 nm. Results are expressed in aglycon units by summing the concentrations of the aglycon isoflavones (genistein, glycitein, and daidzein) and the concentrations of the aglycon equivalents of the corresponding glucoside forms (genistin, glycitin, and daidzin).