The presence of sodium chloride and ammonium chloride in high concentrations inhibits the tryptic hydrolysis of salmine. This action could be due to a protection of the substrate as previously assumed for the native β-lactoglobuline. The inhibiting effect of ammonium chloride does not require the presence of sulfhydryl groups.

The hydrolysis of β-lactoglobulin by trypsin and chymotrypsin is followed to about 90% degradation. It is demonstrated that a simple Henri-Michaelis mechanism (i.e.E + S ⇄ ES → E + P) cannot explain the experimental results. Another mechanism is suggested and discussed.