Cereal Chem 51:658 - 665.  |  VIEW ARTICLE
Chemical and Physical Studies of Mustard and Rapeseed Coats.

J. R. Vose. Copyright 1974 by the American Association of Cereal Chemists, Inc. 

The chemical and physical properties of seed coats derived from a number of species and varieties of mustard and rapeseed were examined. Seed coat polysaccharides were fractionated by a sequential solvent extraction procedure and partially purified by ethanol precipitation. Hydrolyzed polysaccharides were assayed for sugars by gas-liquid chromatography of their TMS derivatives. Unique thickening properties were observed with wet-milled yellow mustard hulls. These were largely a result of the mucilage fraction of the yellow mustard seed coats. This mucilage yielded a far more viscous solution at a 1% w./v. concentration than that obtained from other mustard and rape varieties. Defatted hulls of yellow mustard contained 20 to 25% by weight of mucilage, compared with 3 to 4% in Brassica juncea mustard hulls, and an average of 1% in rapeseed hulls. Refluxing with 2N H2SO4 for 4 hr. completely hydrolyzed the polysaccharide fraction obtained from the cold-water extract of rape and B. juncea mustard hulls. Only 35% of this polysaccharide fraction of yellow mustard hulls was hydrolyzed by this treatment; the residue proved to be cellulose. Hence, the mucilage of yellow mustard appeared to be unique in containing a naturally "solubilized" form of cellulose.