The intercorrelation of the amino acid quality between raw, steeped and germinated guinea corn (Sorghum bicolor) grains

Levels of amino acids were determined in the grains of guinea corn, Sorghum bicolor (L.) Moench. The steeped sample was best in His, Arg, Thr, Ser, Pro, Gly, Ala, Met, Cys, Val, Phe and Tyr contents whereas germinated sample was best in Lys, Asp, Glu, Leu and Ile. The total amino acid contents were: steeped [57.71 g/100 g crude protein (c.p.)], germinated (53.37 g/100 g c.p.) and raw (37.91 g/100 g c.p.) with respective essential amino acids of 30.70 g/100 g c.p., 28.33 g/100 g c.p. and 21.48 g/100 g c.p. Percentage cystine/total sulfur amino acid (% Cys/TSAA) trend was 72.0 (steeped) > 71.1 (germinated) > 58.9 (raw). The Predicted Protein Efficiency Ratio (P-PER) levels were 0.23 steeped, 0.29 (germinated) and none (raw). The Leu/Ile ratio was 0.42 for steeped, 0.38 for germinated and 0.24 for raw grains. The limiting amino acid was Leu for all the samples with 0.30 (steeped), 0.31 (germinated) and 0.16 (raw). The two treatments enhanced the quality of the guinea corn amino acid levels. However, no significant differences occurred between raw/steeped, raw/germinated and steeped/germinated samples at p <0.05. KEY WORDS: Amino acid quality, Raw, Steeped, Germinated, Guinea corn Bull. Chem. Soc. Ethiop. 2008, 22(1), 11-17.