Amino acid composition and biological evaluation of the protein quality of high lysine barley genotypes

The protein quality of high lysine barley genotypes Notch₁ Notch₂,Riso-1508 and Hiproly grown in Indian soil was evaluated by determining amino acid composition and also by rat growth and nitrogen balance studies. Protein and fat contents were found to be highest in Riso-1508. Lysine concentration (5.26 g/16g N) of Riso-1508 was also highest compared to the other high lysine genotypes. Rat feeding trials indicated that the growth promoting qualities of the proteins of genotype Riso-1508 were significantly (p < 0.05) higher than the low lysine barley genotype. The comparatively low lysine barley diet had more digestible protein than the high lysine barley diet. However, the BV and NPU of the high lysine barley were significantly (p < 0.05) higher. This improvement is of importance in meeting the essential amino acid requirements of man as well as other monogastric animals. The study showed that the high lysine barley harvested in Indian agroclimatic conditions retained high lysine quality.