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AACC Approved Methods of Analysis, 11th Edition -AACC Method 86-80.01. Thiamine -- Thiochrome Method

AACC Approved Methods of Analysis, 11th Edition

Vitamins

AACC Method 86-80.01
Thiamine -- Thiochrome Method

VIEW METHOD

Objective
Thiamine, or vitamin B1, in the sample is oxidized to thiochrome using alkaline potassium ferricyanide, after treatment of sample with starch- and protein-degrading enzymes. Thiochrome, which is fluorescent, is extracted in isobutanol for fluorimetric measurement. Highly colored samples or samples containing interfering impurities may require additional purification after extraction and before thiochrome formation. This method measures thiamine in bread and other grain-based products and in corn grits, cornmeal, puffed cereals, farina, and flour.