Effects of Fermentation Conditions and Additives on Myoglobin Forms during Simulated Fermentation of Pork Salami

The effects of fermentation temperature and time as well as environmental solution pH and sodium nitrite and sodium isoascorbate concentrations on myoglobin forms in pork salami were studied.For this,myoglobin from pork salami fermented for different periods of time at different temperatures was extracted with 0.04 mol/L PBS(pH 6.8) and the extract was adjusted to different pH values or added with various concentrations of sodium nitrite and sodium isoascorbate.Various myoglobin solutions were detected at different wavelengths between 480 nm and 640 nm and analyzed for the proportions of three myoglobin forms,deoxymyoglobin,oxymyoglobin and metmyoglobin.The proportion of oxymyoglobin significantly decreased with increasing fermentation temperature during the first 4 h of fermentation;the proportions of metmyoglobin and deoxymyoglobin also significantly decreased,whereas the proportion of oxymyoglobin significantly increased with decreasing environmental pH.For the same fermentation,the proportion of metmyoglobin significantly increased,whereas the proportion of oxymyoglobin significantly decreased with increasing sodium nitrite concentration;the proportion of each myoglobin form showed no significant change with increasing sodium isoascorbate concentration.