Influence of the plating medium in the determination of thermal resistance of Listeria monocytogenes in formulations for hamburger.
The influence of the plating medium used for the recovery of survivors, on the D-values for L. monocytogenes, in formulations for beef hamburger was investigated: 10% fat (F1), 20% fat (F2), 10% fat and 1.5% sodium chloride (F3) and 10% fat and 10.5% hydrated texturized soy protein (F4) were prepare...
| Authors: | , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2008 |
| Country: | Brasil |
| Institution: | Instituto Adolfo Lutz |
| Repository: | Revista do Instituto Adolfo Lutz (Online) |
| Language: | Portuguese |
| OAI Identifier: | oai:ojs.periodicos.saude.sp.gov.br:article/32776 |
| Online Access: | https://periodicos.saude.sp.gov.br/RIAL/article/view/32776 |
| Access Level: | Open access |
| Keyword: | Listeria monocytogenes hamburger heat resistance culture medium hambúrguer resistência térmica meio de cultura |
| Summary: | The influence of the plating medium used for the recovery of survivors, on the D-values for L. monocytogenes, in formulations for beef hamburger was investigated: 10% fat (F1), 20% fat (F2), 10% fat and 1.5% sodium chloride (F3) and 10% fat and 10.5% hydrated texturized soy protein (F4) were prepared and inoculated with a mixture of five strains of L. monocytogenes. Using tryptose phosphate agar containing 1% sodium pyruvate (TPAP) D-values (min) ranged from 36.11 (F1) to 62.76 (F3) at 55.0°C, from 2.55 (F2) to 4.32 (F3) at 60.0°C and from 0.34 (F1 e F2) to 0.52 (F3) at 65.0°C. The D-values, using lithium chloride phenylethanol moxalactam medium (LPM) for enumeration, ranged from 23.05 (F1) to 38.54 (F3) at 55.0°C; from 1.81 (F2) to 3.06 (F3) at 60.0°C and from 0.25 (F2) to 0.37 (F3) at 65.0°C. The z-values (°C), using the TPAP recovery data, ranged from 4.81 (F3) to 4.95 (F4) and from 4.95 (F3) to 5.21 (F4) using the LPM recovery data. The authors concluded that the heat resistance of L. monocytogenes in formulations for beef hamburger can be underestimated when LPM is used as the recovery medium. |
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