Abstract
Model systems were used to investigate certain aspects of the chemical reactions which occur when proteinaceous foods are smoked, especially the role of aldehydes in smoke and basic moieties of the foods. The studies focused upon possible imine formation between aldehydes and free amino acids or lysine side chains in the proteins. Imines were chosen for investigation since the reported characteristics of smoked foods, such as colour, texture and reduction in nutritional value could be due to imine formation. By performing chromatographic (HPLC, TLC) , spectroscopic (UV-vis., IR) and electrophoretic (SDS PAGE) experiments with model systems containing amino acids or proteins, the formation of imines was indicated. Furthermore, other non-imine products were indicated, specifically, cyclization products of histidine and tryptophan. Non-imine products from the 1,2-dihydroxybenzene components of woodsmoke with methionine were also indicated. In further studies the binding affinity of various smoke constituents for fish protein was investigated, however, no differences were detected between aldenydic and phenolic components with respect to the rate of their extraction from fish. It is suggested that this was due to the lability of imines in aqueous solution.