2009_Book_FoodChemistry

690 15 Cereals and Cereal Products
Fig. 15.9. Electrophoretic separation of the glutenins a,b of various wheat cultivars c on polyacrylamide gel in the
presence of sodium dodecyl sulfate and mercaptoethanol (SDS-PAGE) (according to Krause et al., 1988)
a Residue after the extraction of defatted flour with water, salt solution, and aqueous ethanol.
b The numbering of the HMW subunits of glutenin differs from that in the original publication, Payne et al., 1981b: Band 1–7: (x-type),
8–12 (y-type).
c After each variety, the baking quality class is given in brackets (bread volume yield very high: A9, high to very high: A8, high: A7,
average to high: A6, average: B5, low to average: B4, low: B3, very low to low: C2, very low: Cl).
higher and the content of Met (ca. 0.7%) and Phe
(ca. 3.4%) is lower.
The N-terminal sequences determined directly
by Edman degradation correspond to those
derived from the nucleic acids. Apart from
a few variations, the individual amino acid
residues VRVPVPQLQPQN have been found
for these N-terminal sequences (Table 15.16).
The recurring sequences consist of the peptide
unit QPQPFPPQQPYP, which usually occurs