Cereal Chem 45:605 - 611.  |  VIEW ARTICLE
A Basis for Measuring the Intensity of Wheat Flour Pigments.

R. P. A. Sims and M. Lepage. Copyright 1968 by the American Association of Cereal Chemists, Inc. 

The extraction method for measuring content of wheat flour pigment was re-examined, and recommendations for improving the method were made. For relative measurement of p.p.m. carotene, absorbance at 440 millimicrons and absorptivities of 1.9165 in naphtha-alcohol solvent (N/A) and 1.6632 in water-saturated butanol (WSB) are retained. Recommended changes are: the use of 7% absolute ethanol in n-hexane (v./v.) as solvent, and routine instrument checks with standard solutions of potassium chromate in 0.05N aqueous KOH. For absolute values, expressed as mg./100 ml. solution, the true pigments of wheat flour, lutein and its esters, must be used. Absorptivities were determined for the pigments at peak wave lengths in both N/A and WSB; again N/A is the preferred solvent. On the basis of knowledge of the composition of pigments in Thatcher and Mindum wheats, absorptivities were calculated for each flour type.