Shelf life extension, safety, and quality of fresh pork loin treated with high hydrostatic pressure.
The optimal conditions of pressure, time, and processing temperature required to eliminate Listeria monocytogenes Scott A and Salmonella typhimurium ATCC 13311 in fresh pork loin and the effect of these optimal conditions on quality and shelf life were determined. Twenty-five grams of fresh pork loin were inoculated with either of the two organisms and were subjected to pressures between 414 and 827 MPa at either 2 or 25 degrees C for 30 min. The D414MPa(25 degrees C) was determined to be 2.17 min for L. monocytogenes and the D414 MPa (2 degrees C) was determined to be 1.48 min for S. typhimurium. Samples subjected to a 6D process were evaluated by sensory and objective tests as well as for shelf life. These samples were found to be different (P < 0.05) from controls when evaluated after cooking by a triangle test of difference, but only when the pressure was applied at 2 degrees C and not at 25 degrees C. The descriptive analysis test showed that cooked samples treated at 25 degrees C were not different (P > 0.05) from controls in flavor, juiciness, and firmness. Color, peak load, water-holding capacity, and moisture were not found to be different (P > 0.05) between samples treated at 25 degrees C and controls when both were cooked. However, in the raw state, differences were found in the values for color parameters L and b. The level of psychrotrophs was 5.7 log CFU/g for samples treated at 25 degrees C after 33 days of storage at 4 degrees C, as compared with 7.0 log CFU/g for controls. The color and peak load (texture) did not change over the storage period (P > 0.05) in any of the samples. All samples spoiled in 5 days when stored at 25 degrees C.
Ananth
V
V
Department of Microbiology, Immunology & Preventive Medicine, Iowa State University, Ames 50011, USA.
Dickson
J S
JS
Olson
D G
DG
Murano
E A
EA
D000818:Animals; D005511:Food Handling / Q000379:methods* / Q000592:standards*; D005516:Food Microbiology; D005519:Food Preservation; D006874:Hydrostatic Pressure; D008089:Listeria monocytogenes / Q000254:growth & development*; D008460:Meat / Q000382:microbiology*; D011786:Quality Control; D012486:Salmonella typhimurium / Q000254:growth & development*; D013552:Swine; D013696:Temperature; D013997:Time Factors