ALCOHOL-SOLUBLE AND TOTAL PROTEINS FROM AMARANTH SEEDS AND THEIR COMPARISON WITH OTHER CEREALS

The extractibility of alcohol-soluble proteins from different species of Amaranth seeds was studied as a function of water/ethanol (EtOH) and water/2-propanol (2-PrOH) mixtures at concentrations of 45-70%, respectively, with varying amounts of reducing agent 2-mercaptoethanol (2-ME) from 0 to 5%. Most alcohol-soluble proteins were extracted with 55% 2-PrOH/5% 2-ME. On the basis of the results of different extraction methods and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), alcohol-soluble proteins of Amaranth contain 80-85% polypeptides of 10-14 kDa and 7% 20-kDa polypeptides, the rest being minor fractions. Only slight differences were observed in subunits of four Amaranth species. Prolamins and total proteins extracted from oats, rice, maize, and sorghum did not show any electrophoretic relationship with Amaranth alcohol-soluble fractions and total proteins.