ALGERIAN PEARL MILLET Pennisetum glaucum (L.) R. Br: A NEW POTENTIAL SOURCE OF AMINO ACIDS AND NON GLUTEN PROTEINS

Abstract

In South Algeria, pearl millet is cultivated for feed and food. This cereal is well adapted to arid environment. The aim of this study was to identify the suitable cultivars to be used as gluten free source of protein and amino acids. For this purpose, eleven pearl millet cultivars of various colour and shape were sampled from the Algerian Sahara. Wide variability in protein contents (11.2 to 18.2 %.) was found in the studied cultivars. With the exception of one cultivar grown in Tamanrasset, all the local pearl millet samples were higher in protein content than the imported ones. Pearl millet samples were rich in essential amino acids (40% in average). The levels of lysine, threonine, phenylalanine, isoleucine and valine contents in all the sampled cultivars were higher than wheat, maize and sorghum. The extractability of pearl millet protein fractions (albumins, globulins, non reduced prolamins, reduced prolamins and glutelins) was investigated by a combination of size exclusion high performance liquid chromatography (SE-HPLC) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The storage proteins (prolamins and glutelins) varied widely within cultivars and constituted the highest portion of the total extractable proteins in all pearl millet samples, the share of which ranged from 57% to 80%. Prolamins were the major protein fraction in the eleven cultivars (38 to 57% of all extracted proteins). The three pennisetin monomers with molecular masses (MM) of 27, 22 and 12 kDa were separated. This study shows that the sampled pearl millet cultivars from south Algeria, could constitute an alternative and good source of gluten free proteins and essential amino acids.