Injection of Fluids and Microorganisms into Cheese

Principal Investigator:

Dr. Conly Hansen, Utah State University


Carl Brothersen, Utah State University

Project Summary:

Experiments were performed using high pressure injection (HPI) to inject dye into Cheddar, Mozzarella and a small sample of Muenster cheese and microorganisms suspended in water into Muenster cheese blocks. Injection was accomplished by accelerating liquid though sapphire orifices with pressure. In all trials, a single orifice injection nozzle was used. The parameters considered for the depth of penetration studies were: injection pressure (6,890 KPa and 34,500 Kpa (1000-5000 psi)), orifice diameter (102 _m and 152 _m (4 and 6 thousandths of an inch)), injection duration (1,5, and 15 s), and cheese temperature (3.5%C and 20 %C (39%F and 69 %F)). Dye type was varied between polar and nonpolar to indicate which type diffused best in cheese. Cheddar cheese was injected to an average of 161 mm (6.3 inches). Temperature and pressure had the greatest influence on depth of injection. Microbial plate counts showed approximately the same number of bacteria before and after injection. The results of the microbial study indicate the bacteria can be very successfully injected into cheese.





Published Abstract: