title: Effects of pressurization on some contamination flora in beef pate.
abstract: Pate meat is one of the food products at the top of the high-risk category since it is an undercooked product, which does not undergo any treatment to ensure its safety before consumption. In this study, pressurization, a nonthermal technology, was administered to the product to enhance its microbial safety for the 1st time. After being cooked, ground, and mixed with broth and spices, the pate meat was divided into 3 batches. Their additional fat contents were adjusted to 9.11%, 25.00%, and 35.00%, respectively. After the division of each batch again into 3 portions with different acidities (pH 5.65, 5.95, 6.40), they were contaminated with Escherichia coli American Type Culture Collection (ATCC) 11229 or Listeria monocytogenes ATCC 7644. Each batch was treated with 220 or 308 MPa at 21 or 43 °C for 5 or 15 min. Whereas the increase in pressure from 220 to 308 MPa enhanced the antimicrobial effect (P < 0.01), the increase in pH level and fat ratio decreased it. In the study, only the interaction between the fat ratio and acidity was found significantly important. The effect of temperature and time was not significant. The highest microbial inhibition with 1.65 log reduction was observed on E. coli when the pate meat with pH 5.65 and 9.11% fat was treated at 308 MPa at 43 °C for 5 min. The findings indicate the necessity of using higher pressure levels as ≥308 MPa with higher acidity levels (pH ≤ 5.65) and lower fat contents (≤9.11%) to achieve a higher microbial quality in pate meat.
  
  
  CONCLUSIONS
  Different combinations of pressure (308 and 220 MPa), additional fat (9.11, 25.00, or 35.00%), pH (5.65, 5.95, or 6.40), temperature (21 or 43 °C), time (5 or 15 min) on Listeria monocytogenes ATCC 7644 and Escherichia coli ATCC 11229 contamination flora were comparatively studied for the 1st time in pate meat. The findings are especially important for pate meat safety and industry since they indicate the necessity of using pressure levels as ≥308 MPa with higher acidity levels (pH ≤ 5.65) and lower fat contents (≤9.11%) to achieve a higher microbial quality in pate meat, which is highly prone to microbial spoilage.
authors.affiliation: Vocational School of Higher Education, Middle East Technical University, Çankaya İlçesi, Ankara, Turkey. gugur@metu.edu.tr
authors.forename: Ugur
authors.initials: U
authors.lastname: Gogus
mesh_terms: D000818:Animals; D002417:Cattle; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004926:Escherichia coli / Q000254:growth & development / Q000302:isolation & purification; D005506:Food Contamination / Q000517:prevention & control*; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000254:growth & development / Q000302:isolation & purification; D008461:Meat Products; D011312:Pressure; D013696:Temperature