Gas and High-Performance Liquid Chromatographic Analyses of Amino Acids in Soybean Meal, Corn and Triticale

Abstract

Analyses of amino acids in six samples each of soybean meal, corn and triticale by high-pe$ormance liquid chromatography (HPLC) and gas chromatography (GC) were compared. Samples were hydrolyzed in 6 N HCl, then phenylthiocarbamyl ror HPLC) and N-heptaflwrobutyryl for GC) derivatives of free amino acids were prepared and analyzed by the appropriate system. Coeficient of variation within each feedstuffor amino acids analyzed by HPLC rangedfrom 1.8 (leucine) to 23.5 % (methionine) in soybean meal, 2.7 (leucine) to 14.7% (methionine) in corn and 1.7 (leucine) to 14.3 % (cystine) in triticale. Corresponding figures from GC analysis were 0.7 to 22.4%, 1.4 to 14.3 % and 1.6 to 12.1 %, respectively. Linear regression of HPLC on GC values gave goodjts with Rz rangingfrom 0.86 for cystine and 0.99 for isoleucine, leucine, lysine, methionine, phenylalanine, threonine, alanine, aspartic acid and glycine. Although some differences between the two systems were evident, feedstufamino acid values obtained by HPLC and GC analyses compare very well. Results of this study and consideration of such factors as ease of derivatization and length of time for analysis, in our opinion, make HPLC the system of choice.

EVALLUTION of FIBER INGREDIENTS PRODUCED BY ENZYMIC AND/OR YEAST FERMENTATION of TRITICALE

“…The major use of triticale remains as an animal feed ingredient (Adeola et al 1988) and as a forage crop (MacIntyre and Campbell 1973). Triticale has a higher protein content and a slightly better protein quality than wheat (Kies and Fax 1985).…”