Hydrogen sulphide production in eggs and egg products as a result of heating

The nature of the reaction by which H₂S is produced from eggs and egg products during heating was investigated. The possibility of an enzymic reaction, as supposed by others, was examined by using inhibitors for the enzyme mentioned and by heat-inactivation. In both cases the H₂S production was not inhibited. From the stabilities of cysteine, glutathione and egg white determined by H₂S production at different temperatures, it was concluded that the production from egg white must be the result of a non-enzymic reaction from the protein(s). The influence of various factors was investigated. Both ionised SH— and S—S groups are involved in the reaction, since the pH and the S—S/SH ratio are the main factors determining H₂S production. H₂S production increases at higher temperatures and more alkaline pH values. It was shown that in addition to H₂S, lanthionine and NH₃ were present as reaction products.