ZEIN, REGULAR GRADE
FOR PHARMACEUTICAL, COSMETIC AND FOOD USE
ZEIN is the water-insoluble prolamine protein of corn gluten.
Straw-to-yellow colored granular powder, bland in taste.
|Approximate Molecular Weight:||35,000|
|Bulk Density Range:||1.25 - 2.1 gm/10ml|
Positive for (A) and (B) conforms to solubility tests below.
|Solubility in Water:||Insoluble|
|Solubility in 80% alcohol:||Clear to slightly cloudy|
|ZEIN (Protein):||88-96% calculated on a dry basis|
|Loss on Drying:||8% maximum (drying for 2 hours at 105 degrees C)|
|Total Ash:||2% maximum|
|Heavy Metals:||20 ppm maximum|
|Arsenic:||3 ppm maximum|
|Mesh Size:||100% through U.S. 20 mesh|
|Microbial Limits:||The total bacterial count does not exceed|
1000 per gram and the tests for Salmonella
species and Escherichia coli are negative.
|Standard Packaging:||25 kilo poly bag inside double-walled corrugated |
cartons (55.12 lbs. net)
ASSAY METHODS FOR ZEIN
1. Add a few drops of nitric acid t.s. to an aqueous ZEIN suspension - heat it. The solution will be a light yellow color. After adding ammonia t.s., an orange color develops.
2. Add a few drops of copper sulfate t.s. to an alkaline ZEIN solution and warm it in a warm bath. A purple color will develop.
Proceed as directed under “Nitrogen Determination” (461) USP XXI, p. 1207. ZEIN % x 6.25.
Solubility in Alcohol
Dissolve 1 gm in 10 ml of 80% alcohol.
Loss on Drying
Accurately weigh 2.0 gm of sample into a tared weighing dish. Dry at 105 degrees C for two hours. Cool to room temperature in a desiccator. Weigh and calculate the percent loss on drying as follows:
L.O.D. % = Wt. Sample Wet - Wt. Dry X 100
Wt. Sample Wet
Accurately weigh 2 gm of sample into a large tared crucible. Ignite the contents gently, then heat to a dull red. Cool to room temperature in a desiccator and add 1 ml concentrated sulfuric acid. Slowly heat to 800-850 degrees C. Hold at that temperature for two hours. Cool to room temperature in a desiccator. Weigh and calculate the total ash as follows:
Total Ash % = Sample wt. - Wt. residue X 100
Proceed as directed under “Heavy Metals” (231) USP XXI, p. 1189 Method II
Proceed as directed under “Arsenic” (211) USP XXI, p. 1187