The amino acid content of some barley varieties grown in New Zealand

Abstract

Eleven varieties of 2-row barley grown III New Zealand were analysed for 17 amino acids, ammonia, and nitrogen. The varieties were all grown in the one location, Halcombe, in the Rangitikei district of the North Island, and no artificial fertiliser was used. Samples were collected from harvests in two consecutive seasons (1966-67 and 1967-68), and the results were analysed for varietal and seasonal effects on amino acid composition of air-dry samples. Correlations, regressions. and y intercept values, with confidence limits and standard errors, were calculated for amino acid and protein relationships.The barley varieties were Beoma, Delta, Hunter, Maris Baldric, Maris Concord, Piroline, W5690, Zephyr, and three unnamed unselected hybrid bulks (Q61, Q63, and Q66).The nitrogen recovery ranged from 72 to 86%, and the crude protein recovery, using the factor 6.25, ranged from 79 to 98%. No correction for losses of amino acids was made. Only valine analyses showed significant differences between the four replicate analyses of each sample. There were significant seasonal, varietal, and season x variety interaction effects on amino acid concentrations. Most of the significantly higher amino acid concentrations occurred in the drier season . Two of the unselected hybrids contained high protein and amino acid concentrations, and this may have been related to the inclusion of Piroline in their parentage, since Piroline contained the highest amino acid concentrations of the pure lines. Variety Hunter tended to be lowest in amino acid content.The higher the protein content the higher the individual amino acids in all cases, but in general the lower the relative proportion of most of the amino acids in the protein. As the protein concentration increased, glutamic acid and proline accounted for most of the increase, while cystine, arginine, lysine, and histidine also increased their relative contribution.

Identification of Barley Genotypes with Higher Protein Content Coupled with Bold Grains for Food and Malt Barley Improvement under Sub-Tropical Climates

“…It is important to note that the value of lysine, the most limiting essential amino acid in cereals, was 3.36 g/100 g protein in BK 306 was comparable to DWRUB 52 (3.49 g/100 g protein). Dingle and McEwan (1972) reported that proline and glutamic acid accounted for the major increases in amino acids with increasing protein content, and cystine also contributed to a significant extent. However, in the present study it was true for proline and glutamic acid, not for cystine.…”