The composition of amino acids in the light and dark brewer’s spent grain as a food fortification ingredient

Abstract

The objective of this study is to determine the quantitative and qualitative composition of amino acids in light and dark brewer's spent grain. For the research, the spent grain was dried using a convection method to a moisture content of 6.3±0.2%, ground, and sifted to a flour-like consistency. The Ion-Exchange Chromatographic Method was used to determine the quantitative and qualitative composition of amino acids. It was found that the flour from brewer's spent grain contains both essential and non-essential amino acids. The light spent grain contained a greater amount of amino acids compared to the dark. In the light spent grain, the concentration of glutamic acid was 1.15 times higher than in the dark. The content of proline in the light spent grain was 1.1 times greater than in the dark. Serine,

alanine, and glycine were found to be 1.2 times more abundant in the light spent grain than in the dark. Lysine and methionine were also present in 1.5 and 0.9 times greater amounts, respectively, in the light spent grain compared to the dark. Both light and dark spent grains contained equal amounts of cysteine. The study demonstrated that both light and dark brewer's spent grain contain significant amounts of amino acids, which can enrich food products when added. The higher concentration of amino acids in light spent grain compared to dark is associated with the thermal processing technologies used in the production of dark spent grain.