Postpackage Pasteurization of Ready-to-Eat Deli Meats by Submersion Heating for Reduction of Listeria monocytogenes†

2002 ◽  
Vol 65 (6) ◽  
pp. 963-969 ◽  
Author(s):  
P. M. MURIANA ◽  
W. QUIMBY ◽  
C. A. DAVIDSON ◽  
J. GROOMS
Keyword(s):  
Listeria Monocytogenes ◽  
Meat Products ◽  
Current Data ◽  
Surface Phenomena ◽  
Surface Areas ◽  
Surface Imperfections ◽  
Product Surface ◽  
Roast Beef ◽  
Z Value ◽  
High Level

A mixed cocktail of four strains of Listeria monocytogenes was resuspended in product purge and added to a variety of ready-to-eat (RTE) meat products, including turkey, ham, and roast beef. All products were vacuum sealed in shrink-wrap packaging bags, massaged to ensure inoculum distribution, and processed by submersion heating in a precision-controlled steam-injected water bath. Products were run in pairs at various time-temperature combinations in either duplicate or triplicate replications. On various L. monocytogenes–inoculated RTE deli meats, we were able to achieve 2- to 4-log cycle reductions when processed at 195°F (90.6°C), 200°F (93.3°C), or 205°F (96.1°C) when heated from 2 to 10 min. High-level inoculation with L. monocytogenes (~107 CFU/ml) ensured that cells infiltrated the least processed surface areas, such as surface cuts, folds, grooves, and skin. D- and z-value determinations were made for the Listeria cocktail resuspended in product purge of each of the three meat categories. However, reduction of L. monocytogenes in product challenge studies showed much less reduction than was observed during the decimal reduction assays and was attributed to a combination of surface phenomena, including surface imperfections, that may shield bacteria from the heat and the migration of chilled purge to the product surface. The current data indicate that minimal heating regimens of 2 min at 195 to 205°F can readily provide 2-log reductions in most RTE deli meats we processed and suggest that this process may be an effective microbial intervention against L. monocytogenes on RTE deli-style meats.

scholarly journals Microbiological Safety and Organoleptic Quality of Homogenized Sausages Manufactured with Commercial Functional Additives

2021 ◽  
Vol 11 (24) ◽  
pp. 11662
Author(s):  
Anna Fudali ◽  
Iwona Chełmecka ◽  
Anna Marietta Salejda ◽  
Grażyna Krasnowska
Keyword(s):  
Listeria Monocytogenes ◽  
Meat Products ◽  
Consumer Acceptance ◽  
Organoleptic Quality ◽  
Microbiological Safety ◽  
Mesophilic Bacteria ◽  
Functional Additives ◽  
High Level ◽  
Consumer Assessment

The aim of the study was to compare the microbiological safety and sensory quality of meat products manufactured with commercial functional additives. Four functional additives (AFX, AE100, PANA4, FPRX) were used in industrial conditions in the production of homogenized meat products (thick wiener). In order to determine the microbiological safety of final products, the total number of aerobic mesophilic bacteria and the number of Listeria monocytogenes were measured. Consumer assessment and quantitative flavor profiling (QFP) were used for analysis of organoleptic quality. After 7 days of storage, it was found that the effectiveness of the selected additives against the growth of aerobic mesophilic bacteria was unsatisfactory. Only after application of PANA4 did the product not show undesirable changes that would disqualify it from consumption. Each of the functional additives used had a high level of efficacy in inhibiting the growth of Listeria monocytogenes. Meat products with PANA4 addition had the highest consumer acceptance of the overall appearance. The best intensity of flavor bouquet, meat aroma and color, assessed by QFP method, was characterized by the samples with AFX and PANA4 in their recipe.

Prepackage Surface Pasteurization of Ready-to-Eat Meats with a Radiant Heat Oven for Reduction of Listeria monocytogenes

2003 ◽  
Vol 66 (9) ◽  
pp. 1623-1630 ◽  
Author(s):  
NANDITHA GANDE ◽  
PETER MURIANA
Keyword(s):  
Listeria Monocytogenes ◽  
Treatment Time ◽  
Meat Products ◽  
Radiant Heat ◽  
Conveyor Belt ◽  
Treatment Temperature ◽  
Heat Processing ◽  
Processed Meat ◽  
Air Temperatures ◽  
Roast Beef

In this paper, a thermal process for the surface pasteurization of ready-to-eat (RTE) meat products for the reduction of Listeria monocytogenes on such products (turkey bologna, roast beef, corned beef, and ham) is described. The process involves the passage of products through a “tunnel” of heated coils on a stainless steel conveyor belt at various treatment times relevant to the manufacture of processed meat for the surface pasteurization of RTE meat products. Two inoculation procedures, dip and contact inoculation, were examined with the use of a four-strain cocktail of L. monocytogenes prior to heat processing. With the use of radiant heat prepackage surface pasteurization, 1.25 to 3.5-log reductions of L. monocytogenes were achieved with treatment times of 60 to 120 s and air temperatures of 475 to 750°F (246 to 399°C) for these various RTE meats. Reduction levels differed depending on the type of inoculation method used, the type of product used, the treatment temperature, and the treatment time. Prepackage pasteurization (60 s) was also combined with postpackage submerged water pasteurization for formed ham (60 or 90 s), turkey bologna (45 or 60 s), and roast beef (60 or 90 s), resulting in reductions of 3.2 to 3.9, 2.7 to 4.3, and 2.0 to 3.75 log cycles, respectively. These findings demonstrate that prepackage pasteurization, either alone or in combination with postpackage pasteurization, is an effective tool for controlling L. monocytogenes surface contamination that may result from in-house handling.

scholarly journals Efficacy of Cetylpyridinium Chloride against Listeria monocytogenes and Its Influence on Color and Texture of Cooked Roast Beef†

2005 ◽  
Vol 68 (11) ◽  
pp. 2349-2355 ◽  
Author(s):  
M. SINGH ◽  
H. THIPPAREDDI ◽  
R. K. PHEBUS ◽  
J. L. MARSDEN ◽  
T. J. HERALD ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Cetylpyridinium Chloride ◽  
Meat Products ◽  
Plate Count ◽  
Bacterial Populations ◽  
Plate Counts ◽  
Roast Beef ◽  
Aerobic Plate Count

Sliced (cut) and exterior (intact) surfaces of restructured cooked roast beef were inoculated with Listeria monocytogenes, treated with cetylpyridinium chloride (CPC; immersion in 500 ml of 1% solution for 1 min), individually vacuum packaged, and stored for 42 days at 0 or 4°C. Noninoculated samples were similarly treated, packaged, and stored to determine effects on quality (color and firmness) and on naturally occurring bacterial populations, including aerobic plate counts and lactic acid bacteria. Immediately after CPC treatment, regardless of inoculation level, L. monocytogenes populations were reduced (P = 0.05) by about 2 log CFU/cm2 on sliced surfaces and by about 4 log CFU/cm2 on exterior surfaces. Throughout 42 days of refrigerated storage (at both 0 and 4°C), L. monocytogenes populations on CPC-treated samples remained lower (P = 0.05) than those of nontreated samples for both surface types. After 42 days of storage at both 0 and 4°C, aerobic plate count and lactic acid bacteria populations of treated samples were 1 to 1.5 log CFU/cm2 lower (P = 0.05) than those of nontreated samples for both surface types. CPC treatment resulted in negligible effects (P > 0.05) on the color (L*, a*, and b* values) of exterior and sliced roast beef surfaces during storage. For both sliced and exterior surfaces, CPC-treated samples were generally less firm than nontreated samples. CPC treatment effectively reduced L. monocytogenes populations on roast beef surfaces and resulted in relatively minor impacts on color and texture attributes. CPC treatment, especially when applied to products prior to slicing, may serve as an effective antimicrobial intervention for ready-to-eat meat products.

Surface Pasteurization of Vacuum-Sealed Precooked Ready-to-Eat Meat Products

2006 ◽  
Vol 69 (2) ◽  
pp. 459-468 ◽  
Author(s):  
JACQUES H. HOUBEN ◽  
FRITS ECKENHAUSEN
Keyword(s):  
Food Processing ◽  
Meat Products ◽  
Review Of The Literature ◽  
Production Lines ◽  
Destructive Sampling ◽  
Surface Imperfections ◽  
Surface Irregularities ◽  
Product Surface ◽  
Fully Cooked ◽  
Cooked Meat

Pathogens may contaminate ready-to-eat meat products after cooking but before packaging. Listeria monocytogenes is a formidable contaminant in the food processing environment and is relatively heat resistant compared with other non–spore-forming pathogens. As a consequence, this microorganism is commonly chosen for evaluation in postpackage pasteurization studies. The aim of this study was to review information on the thermal surface pasteurization of vacuum-sealed precooked ready-to-eat meat products, bearing in mind the conditions of commercial production lines, and to formulate a guideline for pasteurization intensity. Review of the literature revealed that fewer microorganisms were killed at the product surface than would be expected based on the results of volumetric thermal resistance studies. Mathematical modeling studies indicated that this low kill might be due to surface imperfections that shield bacteria from the heat. More information on contamination with L. monocytogenes (and other possible pathogens) in process lines and their potential migration into product surface irregularities is urgently required. Studies involving destructive sampling (surface shaving) methods and inoculation with pathogens, both at realistic and inflated levels, should be performed with various product types. Published reports suggest that postpackage pasteurization of fully cooked meat products (weighing up to 9 kg) by water submersion (96°C) for about 10 min should achieve a 2- to 4-log destruction of L. monocytogenes on the product surface. If heating at this temperature and duration is not feasible for product quality or logistic reasons, the inherent bacteriological stability of the product should be increased so that the intensity of surface pasteurization can safely be reduced.

Thermal Inactivation of Listeria monocytogenes on Ready-to-Eat Turkey Breast Meat Products during Postcook In-Package Pasteurization with Hot Water

2003 ◽  
Vol 66 (9) ◽  
pp. 1618-1622 ◽  
Author(s):  
R. Y. MURPHY ◽  
L. K. DUNCAN ◽  
K. H. DRISCOLL ◽  
J. A. MARCY ◽  
B. L. BEARD
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Listeria Monocytogenes ◽  
Meat Products ◽  
Heating Time ◽  
Hot Water ◽  
Cooling Time ◽  
Breast Meat ◽  
Packaging Films ◽  
Product Surface

The inactivation of Listeria monocytogenes during postcook in-package pasteurization was evaluated for fully cooked turkey breast meat products (4-kg packages). The products were surface-inoculated to contain 107 CFU of L. monocytogenes per cm2 of product surface. The inoculated products were vacuum-packaged in different thicknesses (0.08 to 0.33 mm) of packaging films and treated with hot water at 96°C. After heat treatment, the products were immediately cooled in an ice water bath at 0°C. The relationship between heating time and product surface temperature was determined for different thicknesses of packaging films. The effectiveness of heat treatment for inactivating the pathogen was affected by product surface roughness. About 50 min of heating time was needed to achieve a thermal kill of 7 log10 CFU/cm2 on products with surface roughness up to 15 mm in depth. The cooling time needed after a heat treatment increased with an increasing endpoint temperature of the heated product and the heat penetration depth reached in the product. The cooling time needed to cool the product from 71°C to 4°C was about 2.5-fold the heating time.

Evaluation of Novel Micronized Encapsulated Essential Oil–Containing Phosphate and Lactate Blends for Growth Inhibition of Listeria monocytogenes and Salmonella on Poultry Bologna, Pork Ham, and Roast Beef Ready-to-Eat Deli Loaves

2015 ◽  
Vol 78 (4) ◽  
pp. 698-706 ◽  
Author(s):  
G. CASCO ◽  
T. M. TAYLOR ◽  
C. Z. ALVARADO
Keyword(s):  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Essential Oil ◽  
Antimicrobial Agents ◽  
Meat Products ◽  
Negative Control ◽  
Lag Phase ◽  
Phase Extension ◽  
Roast Beef ◽  
Final Batch

Essential oils and their constituents are reported to possess potent antimicrobial activity, but their use in food processing is limited because of low solubility in aqueous systems and volatilization during processing. Two proprietary noncommercial essential oil–containing phosphate blends were evaluated for antimicrobial activity against Salmonella enterica cocktail (SC)–and Listeria monocytogenes (Lm)–inoculated deli meat products made from pork, poultry, or beef. Four treatments were tested on restructured cured pork ham, emulsified chicken bologna, and restructured beef loaf: nonencapsulated essential oil with phosphate version 1 at 0.45% of final batch (EOV145; chicken and pork, or EEOV245 beef), micronized encapsulated essential oil with phosphate version 2 at 0.60% of final batch (EEOV260), a 2.0% potassium lactate (PL) control, and a negative control (CN) with no applied antimicrobial agent. Compared with the CN, none of the antimicrobial agents (EEOV260, EOV145, PL) successfully limited Lm or SC growth to <2.0 log cycles over 49 days or 35 days of refrigerated storage, respectively. The PL and EEOV260-treated ham loaves did show Lm growth limiting ability of up to 1 log cycle by days 35 and 42. On formed roast beef, the EEOV260 was able to extend the lag phase and inhibited the growth of Lm in the same manner as the PL. For SC-treated samples, the following effects were observed: in poultry bologna treated with EEOV260, a lag-phase extension was observed through 35 days of storage compared with the other samples. For pork deli loaves, the EEOV260 inhibited growth of SC at days 21 and 28 to the same level of efficacy as PL (0.5 log cycle). In roast beef samples, on day 35, the SC growth was inhibited ca. 0.5 log CFU/g by EEOV260 when compared with the CN. In conclusion the EEOV260 can function to replace PL to limit Salmonella and Lm growth in ready-to-eat deli products. Further testing is needed to ensure consumer acceptability.

Identifying Ingredients That Delay Outgrowth of Listeria monocytogenes in Natural, Organic, and Clean-Label Ready-to-Eat Meat and Poultry Products

2013 ◽  
Vol 76 (8) ◽  
pp. 1366-1376 ◽  
Author(s):  
LINDSEY M. McDONNELL ◽  
KATHLEEN A. GLASS ◽  
JEFFREY J. SINDELAR
Keyword(s):  
Listeria Monocytogenes ◽  
Sodium Nitrite ◽  
Antimicrobial Agents ◽  
Meat Products ◽  
Sodium Lactate ◽  
Powder Blend ◽  
Staphylococcus Carnosus ◽  
Poultry Products ◽  
Roast Beef ◽  
Delayed Growth

The objective of this study was to identify ingredients that inhibit Listeria monocytogenes in natural, organic, or clean-label ready-to-eat meat and poultry products. Fourteen ingredients were screened in uncured (no-nitrate-or-nitrite-added), traditional-cured (156 ppm of purified sodium nitrite), cultured (alternative cured, natural nitrate source, and Staphylococcus carnosus), or preconverted (alternative cured, natural nitrite source) turkey slurries. Slurries were cooked, cooled, inoculated to yield 3 log CFU/ml L. monocytogenes, stored at 4°C, and tested weekly for 4 weeks. Three antimicrobial ingredients, 1.5% vinegar–lemon–cherry powder blend, 2.5% buffered vinegar, and 3.0% cultured sugar–vinegar blend, were incorporated into alternative-cured ham and uncured roast beef and deli-style turkey breast. Controls included all three meat products without antimicrobial ingredients and a traditional-cured ham with 2.8% sodium lactate–diacetate. Cooked, sliced products were inoculated with 3 log CFU/g L. monocytogenes, vacuum packed, and stored at 4 or 7°C, for up to 12 weeks. For control products without antimicrobial agents stored at 4°C, a 2-log L. monocytogenes increase was observed at 2 weeks for ham and turkey and at 4 weeks for roast beef. Growth (>1-log increase) in the sodium lactate–diacetate was delayed until week 6. Compared with the control, the addition of either vinegar–lemon–cherry powder blend or buffered vinegar delayed L. monocytogenes growth for an additional 2 weeks, while the addition of cultured sugar–vinegar blend delayed growth for an additional 4 weeks for both ham and turkey. The greatest L. monocytogenes delay was observed in roast beef containing any of the three antimicrobial ingredients, with no growth detected through 12 weeks at 4°C for all the treatments. As expected, L. monocytogenes grew substantially faster in products stored at 7°C than at 4°C. These data suggest that antimicrobial ingredients from a natural source can enhance the safety of ready-to-eat meat and poultry products, but their efficacy is improved in products containing nitrite and with lower moisture and pH.

scholarly journals Listeria monocytogenes Cold Shock Proteins: Small Proteins with A Huge Impact

2021 ◽  
Vol 9 (5) ◽  
pp. 1061
Author(s):  
Francis Muchaamba ◽  
Roger Stephan ◽  
Taurai Tasara
Keyword(s):  
Listeria Monocytogenes ◽  
Stress Tolerance ◽  
Cold Shock ◽  
Current Data ◽  
Health Concern ◽  
Stress Exposure ◽  
Cold Shock Proteins ◽  
Cell Functions ◽  
Small Proteins ◽  
Shock Proteins

Listeria monocytogenes has evolved an extensive array of mechanisms for coping with stress and adapting to changing environmental conditions, ensuring its virulence phenotype expression. For this reason, L. monocytogenes has been identified as a significant food safety and public health concern. Among these adaptation systems are cold shock proteins (Csps), which facilitate rapid response to stress exposure. L. monocytogenes has three highly conserved csp genes, namely, cspA, cspB, and cspD. Using a series of csp deletion mutants, it has been shown that L. monocytogenes Csps are important for biofilm formation, motility, cold, osmotic, desiccation, and oxidative stress tolerance. Moreover, they are involved in overall virulence by impacting the expression of virulence-associated phenotypes, such as hemolysis and cell invasion. It is postulated that during stress exposure, Csps function to counteract harmful effects of stress, thereby preserving cell functions, such as DNA replication, transcription and translation, ensuring survival and growth of the cell. Interestingly, it seems that Csps might suppress tolerance to some stresses as their removal resulted in increased tolerance to stresses, such as desiccation for some strains. Differences in csp roles among strains from different genetic backgrounds are apparent for desiccation tolerance and biofilm production. Additionally, hierarchical trends for the different Csps and functional redundancies were observed on their influences on stress tolerance and virulence. Overall current data suggest that Csps have a wider role in bacteria physiology than previously assumed.

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