Nutritional yield and amino acid profile of rice protein as influenced by nitrogen fertilizer

Abstract

The proximate and amino acid composition of rice (Cv. IR. 9-60) as influenced by different levels (30, 60 and 90 kg/ha) of nitrogen (as urea), was evaluated. The experimental soil was clay-loam and alkaline (pH 7.8), deficient in organic matter and nitrogen contents. On such soil the grain yield and protein content were significantly (p = 0.05) increased with increasing levels of nitrogen. Protein and carbohydrate production per unit area showed similar trend. Although higher levels (60 and 90 kg/ha) of nitrogen reduced the lysine content of grain, the resulting protein still contained sufficient amount of all the essential amino acids to fulfill the adult human requirements. However, it was deficient in lysine: for child nutrition. Protein quality was adversely affected by higher doses of nitrogen. However, the proportion of lysine relative to tryptophan was little affected.