Thioctic acid in wheat flour

The presence of thioctic acid in wheat flour has been confirmed and a concentrated extract, which, however, contains impurities, has been prepared. The acid was identified by its ultra‐violet absorption maximum at 320‐328 mμ, whereas in the absence of impurities its absorption maximum is at 334 mμ. Thioctic acid was also identified as its methyl ester by gas chromatography. Comparisons were made on its distribution in the mill streams of a wheat sample.