Osborne fraction, cereal

Hahn, B., Grosch, W. 1998. Distribution of glutathione in Osborne fractions as affected by additions of ascorbic acid, reduces and oxidised glutathione. J Cereal Sci 27 117-125. 

Table 15.13. Amino acid composition (mole %) of the Osborne fractions of various cereals...

Cereal proteins when classified by the Osborne sequential extraction method yield four different classes albumins, which are water soluble, globulins, which are soluble in salt solutions, prolamins, which are soluble in alcohol-water mixtures, and glutelins, which are soluble in dilute acid or alkali. Chen and Bushuk added a fifth fraction by dividing the glutelin into two fractions, one soluble in dilute (0.05 m) acetic acid and the other insoluble in this reagent.5... 

Although Osborne s fractionation was a major milestone in the development of cereal chemistry, it must be understood that each of these fractions is a complex mixture of different polypeptides, and also that these polypeptides overlap in their solubilities. This is particularly true for the gliadins and glutenin proteins. Beckwith et al. (1966) detected by gel filtration studies a small fraction of the ethanol-soluble proteins as an excluded peak, which he called gliadin of high molecular weight (HMW) [5]. Nielsen et al. (1968) found that... 

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