Microbial sampling and analysis
Twenty-five g of the meat mixture were taken from the patties,and diluted in 225 mL of 0.1% sterile peptone water.
Each sample was homogenized in a Stomacher Lab Blender (model BA6021;Seward Laboratory UAC House, London, U.K.) for 1 min.
Serial 10-fold dilutions were prepared by diluting 1 mL in 9 mL of 0.1% sterile peptone water.
Two plates were prepared from each dilution by pouring 1 mL in fluid agar.
Counts of aerobic psychrotrophic flora were determined from plates bearing 20 to 200 colonies in plate count agar incubated at 7 °C for10 d.
Counts were expressed as the log 10 of colony forming units/g.