LIBERATION OF STALING ALDEHYDES DURING STORAGE OF BEER
Roger Barker, D. E. F. Gracey, A. J. Irwin, P. Pipasts, E. Leiska
Journal of the Institute of Brewing
Abstract
Trans-2-nonenal, 3-hydroxynonanal and 3-hydroxybutanal were isolated from barley and wort and mass spectral evidence for the presence of further hydroxyaldehydes was found. The concentration of free aldehydes in a model solution was found to decrease in the presence of bisulphite. Addition of acetaldehyde to a mixture of aldehyde bisulphite complexes released trans-2-nonenal in preference to other aldehydes. The concentration of sulphite in beer decreased by 66% over four months. This data was combined in a theory in which the papery, cardboard stage of beer staling is ascribed to a decrease in bisulphite concentration and subsequent bisulphite transfer from unsaturated aldehyde bisulphite addition complexes.
Extracted Claims
5 claims extracted from this paper into the knowledge graph
acetaldehyde released trans-2-nonenal
“Addition of acetaldehyde to a mixture of aldehyde bisulphite complexes released trans-2-nonenal in preference to other aldehydes.”
free aldehydes decreased concentration
“The concentration of free aldehydes in a model solution was found to decrease in the presence of bisulphite.”
bisulphite transferred from unsaturated aldehyde bisulphite addition complexes
“This data was combined in a theory in which the papery, cardboard stage of beer staling is ascribed to a decrease in bisulphite concentration and subsequent bisulphite transfer from unsaturated aldehy...”