EVALUATION OF PROTEIN-QUALITY OF SORGHUM [SORGHUM-BICOLOR (L) MOENC]

Grain protein content varied from 6.8% to 19.6% in eight sorghum cultivars comprising land races, hybrids, and local cultivars. Amino acid contents and distribution of Landry and Moreaux protein fractions in grains were studied. Two Ethiopian land races had higher concentrations of lysine and threonine, as well as cystine, isoleucine, and tyrosine. Fraction I, comprising albumin-globulin including nonprotein nitrogen, and fraction V (glutelin) together constituted about 41-55% of the protein in the eight sorghum cultivars. Variation in fraction II (prolamin) and fraction III (cross-linked prolamin) contents was observed among the cultivars. To elucidate the pattern of synthesis of protein fractions in grain, studies were made at different grain maturity periods, using one cultivar. Fraction I synthesis was initiated at 7 days after anthesis. Prolamin increased from 14 to 28 days and declined toward maturity. Glutelin did not change beyond 14 days after anthesis until maturity. © 1990, American Chemical Society. All rights reserved.