Amino acid composition of spring wheats and losses of lysine during chapati baking

Abstract

Forty-four spring wheat varieties representing 64 years of wheat cultivar releases were evaluated for amino acid composition. The concentration of several amino acids differed among the wheat varieties but amino acids did not significantly consistently among wheat varieties and growth conditions. Significant differences existed in amino acid score due to wheat varieties and crop years. The variations in amino acids (g/100 g flour) were found in lysine 0.255–0.392, leucine 0.449–0.927, isoleucine 0.224–0.492, threonine 0.277–0.516, valine 0.288–0.587, methionine 0.072–0.160, histidine 0.118–0.265, arginine 0.149–0.643, alanine 0.036–0.119, aspartic acid 0.453–0.841, glutamic acid 0.743–1.313, glycine 0.393–0.753, proline 0.851–1.420, serine 0.409–0.722 and tyrosine 0.189–0.597. The chapatis contained on average lysine 0.261, leucine 0.542, isoleucine 0.277, threonine 0.353, valine 0.359, methionine 0.101, histidine 0.159, arginine 0.285, alanine 0.063, aspartic acid 0.618, glutamic acid 0.844, glycine 0.526, proline 1.088, serine 0.538 and tyrosine 0.283 (g/100 g). The wheat varieties Punjab 96, Shahkar 95, Inqulab 91 and C518 contained relatively higher concentration of different amino acids as compared to other wheat varieties. Loss in content of amino acids was observed during baking of chapatis. The decline in lysine content ranged from 1.11% to 23.58% during chapati baking (12.4% protein basis). The amino acid scores in wheat varieties and chapatis were 45 and 40, respectively. The mean crude protein content in chapatis was 11.85%.