Post-Packaging Pasteuriza

Will it work with 

country-cured hams? 

Benjy Mikel 

Professor/ Coordinator 

Food Sciences 
Perhaps we should let him fry a bit longer on the a

can’t be too careful these days about undercoo
Listeria and 10240.4 

• Is Listeria in your plant? 

» Probably 

• Is it on your RTE product? 

» Hopefully not 

• What measures can you take? 

» Sanitation » Anti-microbials » Post-packaging pasteurization 
Risk Management Strate

• Eliminate L. monocytogenes from the 

environment of processing plants thatproduce ready-to-eat foods 

• Use a pasteurization processes to des

monocytogenes 

– In-pack pasteurization, or – Immediately before packaging 

• Use product formulations that prevent 

growth of L. monocytogenes 
USDA-FSIS Alternative

• Alt 1. Post-lethality AND Antimicrob• Alt 2. Post-lethality OR Antimicrob• Alt 3. Sanitation Only 
Post-Packaging Pasteurization 
Non-Thermal Post

Packaging Treatmen

• High Pressure (HPP) 

• Expensive, batch process 

• Pulsed Electric Field (PEF) 

• better with fluid products • Ultraviolet (UV) Light – Lm resistant, surface e

• Electrolyzed oxidizing water 

• Not near term 

• Irradiation 

• some promise, not near term 
Post-Packaging 

Heat/Pasteurization 

• Heat re-applied to package surface

destroy any surface cross contami

• Immerse pkg. in hot water • Surface steam (205F, 15 sec) • Hot air or infrared. 

• Pasteurization for 2 or 4 min at 96.1 C r

LM by 2 and 4 logs (Gill et al., 2002) 

• Reheat 60-90 sec @195-205 F • Steam or H2O • Goal: 2-3 mm of product to 160 F for 15• Immediate chill and 3-4 log reduction • Shelflife- increase 25-33% 

Post-Packaging Hea

Disadvantages 

• Difficult to heat all surfaces • May adversely affect package. • Product changes with heat (color, textu

etc.) 

• Expensive • Apply heat/moisture in refrigerated roo

(condensation, etc.) 
Individually-Wrapped Produc

Easiest to Post-Package Pasteu
Comparison of Pasteurization Meth

• 

Hot Water Bath 

Advantages: Simple method. Disadvantages: Process time, approx. 8 minutes.

Increases internal product temperature.Lack of uniform surface heat distribution. Heating large volumes of water. 

Steam Chamber Advantages: Simple method. Disadvantages:Long processing time, approx. 15 minutes.Increases internal product temperature. Lack of uniform surface heat distribution. 

Poor energy utilization. Circulating Water Advantages: Short processing time (3 minutes) does not affect characteristics. Very uniform surface heat distribution.Most efficient energy utilizationClose ratio of water/product. 
Steam Surface Pasteuriza

* A joint development by ALKAR-RapidPak, Inc., Kraft/Oscar-Mayer 

SSP module extends length by two indexes 

• Provides a surface kill step immediately before packag• Adapts to existing line, no effect on line speed or packa

Graphics and information provided by ALKAR-RapidPak, Inc. 
' ... 

I 

Steam Surface Pasteuriz

Machine Configuration 

Top film 

Discharge 

Fil

Cut Seal SSP Load 

Cool 

heat For

treatment 

SSP step = 1.5 sec of high pressure s

Graphics and information provided by ALKAR-RapidPak, Inc. 
[ill] [ill] [ill] ITT] 

u!ill mm 

[Ilil

l 

Steam Surface Pasteuriza

Vacuum Cooling 

Steam Injection 

Servo lifts product pedestal up into 

SSP chamber 

Graphics and information provided by ALKAR-RapidPak, Inc. 
Steam Surface Pasteuriza

High Pressure Steam Inj

Vent Condensate Po

• Maximum contact time on most difficult area --- ends • 1.5 second cycle time with 4 alternating steam bursts 

Bursts 1 and 3 Bursts 2 and 4 

Graphics and information provided by ALKAR-RapidPak, Inc. 
Steam Surface Pasteuriz

• Hot dogs inoculated with indicator

microorganism 

• SSP treatment = 1.5 seconds • 4-log reduction for single-layer packag

configuration 

• Actual Listeria monocytogenes inocula

pack tests (102 per package) resulted 

positives 

• Double-layer package tests in progres

– Preliminary findings show 2.0 - 2.5 log red

Graphics and information provided by ALKAR-RapidPak, Inc. 
In-Package Pasteuriza

Stork RMS-Protecon (Townsend) Steam-Based 

Post-Process Pasteurization System 

Data and images supplied by Drs. James Marsden and Randall Phebus, Kansas State U
In Package Pasteuriza

Log cycle reduction of Listeria monocytogenes at 9

0 1 2 3 4 5 6 7 8 

i 

g 

0 MIN 2 MIN 3 MIN 4 MIN 

Treatment T me 

LOG CFU/ 

Data and images supplied by Drs. James Marsden and Randall Phebus, Kansas State U
Table 3.1. Background bacterial populations and product characteristics 

a Below detectable limits.

Table 3.1. Background bacterial populations and product characteristics 

Listeria monocytogenes < DLa 

c Staphylococcus aureus 5.66 

b (0.71) 

Lactic acid bacteria 6.44 (0.18) Aerobic Plate counts 6.35 (0.35) 

pH 6.27 (0.11) 

Aw 0.88 (0.02) Salt 6.65 (1.31) 

a Below detectable limits. b Bacterial populations are in Log10 / gm. c Numbers within parentheses are standard deviations. 
(AU) of antimicrobial compounds.

ml)

Table 3.2. Minimum inhibitory concentration (MIC) and Activity U(AU) of antimicrobial compounds. 

Compound MIC AU (AU 

ml) 

Nisin 2.0 

μg / ml 3,200 

Liquid Smoke L (Charsol® Supreme Hickory)a 

1 % soln v/v 1,600 

Liquid Smoke P (Charsol® Supreme Poly Hickory & Polysorbate 80) 

0.5 % soln v/v 1,600 

a Liquid smoke compounds were graciously donated by the Red Arr

Co. 
Table 3.4. Log10 reductions of L. m. populations on non-steamed vs. steamed country ham

slices.

 Non-steamed Steamed

Days Days

Compounds 0 3 7 0 3 7

 2.40bcd C 1.98 N abc BC isin 0.31ab A 1.35b B 1.45b B 2.49c C

(2 μg/ml)

 3.00 N bcd C 5x 1.13c A 2.27c BC 1.96c B 2.62c BC 2.95de C

(10 μg/ml)N10x 0.86bc A 2.04c B 2.17c B 2.33c B 3.43c C 3.72d C(20 μg/ml)

 0.14ab A 0.88a A 1.02a A 0.63ab A 2.43cd B 3.28cd B L

(1% v/v)

 1.62abc BC 2.26abc C L2 0.20ab A 0.80a AB 1.00a AB 0.61abAB

(3% v/v)L4 0.11ab A 0.92a B 0.97aB 0.35a A 1.55abc C 1.73ab C(5% v/v)P 0.18ab A 0.90a BC 0.93a BC 0.72ab B 1.24a C 1.73ab D(0.5 % v/v)P2 0.00a A 0.75a B 0.89a B 0.74ab B 1.50ab C 1.04a B(2.5 % v/v)P4 0.12ab A 0.71a B 0.79a B 1.10b B 1.29a B 1.20a B(4.5 % v/v)Control 0.16ab A 0.66a B 0.78a B 0.52ab AB 1.43a C 1.27a C(Buffer)abcd Different letters within the same column are significant (P < 0.05).ABCD Different letters within the same row are significant (P < 0.05).

Table 3.4. Log10 reductions of L. m. populations on non-steamed vs. steamed country ham 

slices. 

Non-steamed Steamed 

Days Days 

Compounds 0 3 7 0 3 7 

2.4 0bcd C 1 .98 N abc BC isin 0.31ab A 1.35b B 1.45b B 2.49c C 

(2 μg/ml) 

3 .00 N bcd C 5x 1.13c A 2.27c BC 1.96c B 2.62c BC 2.95de C 

(10 μg/ml) 

N10x 0.86bc A 2.04c B 2.17c B 2.33c B 3.43c C 3.72d C 

(20 μg/ml) 

L 0.14ab A 0.88a A 1.02a A 0.63ab A 2.43cd B 3.28cd B 

(1% v/v) 

1.62abc BC 2.26abc C L2 0.20ab A 0.80a AB 1.00a AB 0.61abAB 

(3% v/v) L4 0.11ab A 0.92a B 0.97aB 0.35a A 1.55abc C 1.73ab C (5% v/v) P 0.18ab A 0.90a BC 0.93a BC 0.72ab B 1.24a C 1.73ab D 

(0.5 % v/v) 

P2 0.00a A 0.75a B 0.89a B 0.74ab B 1.50ab C 1.04a B 

(2.5 % v/v) 

P4 0.12ab A 0.71a B 0.79a B 1.10b B 1.29a B 1.20a B 

(4.5 % v/v) 

Control 0.16ab A 0.66a B 0.78a B 0.52ab AB 1.43a C 1.27a C 

(Buffer) 

abcd Different letters within the same column are significant (P < 0.05). ABCD Different letters within the same row are significant (P < 0.05). 
Table 3.6. Log10 reductions of L. m. populations against control (buffer) at 0 time, in broths

containing elevated levels of NaCL, dextrose, sodium nitrite and antimicrobials.

 Time (min)

Compounds 0 0.5 1 2 5 10 15 30 60

Nisin (5x)

(10μg/ml)

 0.03b A 0.09b A 0.55b B 0.89d C 0.98d CD 1.09c D 1.68d E 1.66c E 2.60d F

Nisin (10x) 0.10a A(20μg/ml)

 0.14b B 0.38b C 1.04e D 1.62e D 2.03e EF 1.93e E 2.24d FG 2.34cG

L 2(3 % v/v)

0.08b A 0.07ab A 0.09a A 0.22c AB 0.30bc B 1.06c C 1.10c C 7.28f D 7.28eD

L 4(5 % v/v)

0.03b A 0.11b A 0.07a A 0.24c B 0.41c C 1.51d D 1.66d E 7.28f F 7.28eF

P 2 0.03b A(2.5 % v/v)

 0.06ab A 0.00a A 0.18bc B 0.21b BC 0.32b C 0.63b D 0.96b E 1.31bF

P 4 0.01b A(4.5 % v/v)

 0.13b AB 0.08a AB 0.07ab AB 0.20b BC 0.33b C 1.09c D 2.74e E 7.28eF

Control 0.00b A 0.01a A 0.00a A 0.00a A 0.04a AB 0.03a AB 0.08aAB 0.09a AB 0.13aB(buffer)abc different letters within the same column are significant (P < 0.05)ABC different letters within the same row are significant (P < 0.05)

Table 3.6. Log10 reductions of L. m. populations against control (buffer) at 0 time, in broths 

containing elevated levels of NaCL, dextrose, sodium nitrite and antimicrobials. 

Time (min) 

omCpounds 0 0.5 1 2 5 10 15 30 60 

Nisin (5x) 

(10μg/ml) 

0.03b A 0.09b A 0.55b B 0.89d C 0.98d CD 1.09c D 1.68d E 1.66c E 2.60d F 

Nisin (10x) 0.10a A (20μg/ml) 

0.14b B 0.38b C 1.04e D 1.62e D 2.03e EF 1.93e E 2.24d FG 2.34cG 

L 2 

(3 % v/v) 

0.08b A 0.07ab A 0.09a A 0.22c AB 0.30bc B 1.06c C 1.10c C 7.28f D 7.28eD 

L 4 (5 % v/v) 

0.03b A 0.11b A 0.07a A 0.24c B 0.41c C 1.51d D 1.66d E 7.28f F 7.28eF 

P 2 0.03b A 

(2.5 % v/v) 

0.06ab A 0.00a A 0.18bc B 0.21b BC 0.32b C 0.63b D 0.96b E 1.31bF 

P 4 0.01b A(4.5 % v/v) 

0.1 3b AB 0.08a AB 0.07ab AB 0.20b BC 0.33b C 1.09c D 2.74e E 7.28eF 

Control 0.00b A 0.01a A 0.00a A 0.00a A 0.04a AB 0.03a AB 0.08aAB 0.09a AB 0.13aB 

(buffer) 

abc different letters within the same column are significant (P < 0.05) ABC different letters within the same row are significant (P < 0.05) 
Table 3.12. Minolta L * values of non-steamed vs. steamed country ham slic

days storage.

 Non-steamed Steamed

Days Days

 0 3 7 0 3 

Treatments

N5x 51.06A 50.00A 49.00

A 51.13A 51.77

A 

a (10

μg/ml) (3.02) (2.63) (3.32) (1.48) (2.94) 

N10x 49.71A 49.04

A 51.18A 48.04

A 51.01

A 

(20

μg/ml) (4.27) (3.72) (4.30) (2.58) (4.83) 

L4 51.29A 45.86

A 49.00A 50.22

A 46.08

A 

(5% v/v) (3.94) (5.27) (3.32) (2.92) (3.23) P4 47.91A 51.95

A 51.06A 53.64

A 50.14AB 

(4.5% v/v) (2.45) (1.41) (4.52) (3.32) (1.84) 

Control 49.82

A 49.13

A 45.78

B 51.36

A 50.00A 

(buffer) (2.36) (0.38) (1.17) (2.11) (2.52) a Numbers in the parentheses are the standard deviations.ABC Different letters within the same row are significant (P < 0.05).Table 3.12. Minolta L * values of non-steamed vs. steamed country ham slicdays storage. 

Non-steamed Steamed 

Days Days 

0 3 7 0 3 

Treatments 

N5x 51.06A 50.00A 49.00

A 51.13A 51.77

A 

a (10 

μg/ml) (3.02) (2.63) (3.32) (1.48) (2.94) 

N10x 49.71A 49.04

A 51.18A 48.04

A 51.01

A 

(20 

μg/ml) (4.27) (3.72) (4.30) (2.58) (4.83) 

L4 51.29A 45.86

A 49.00A 50.22

A 46.08

A 

(5% v/v) (3.94) (5.27) (3.32) (2.92) (3.23) P4 47.91A 51.95

A 51.06A 53.64

A 50.14AB 

(4.5% v/v) (2.45) (1.41) (4.52) (3.32) (1.84) 

Control 49.82

A 49.13

A 45.78

B 51.36

A 50.00A 

(buffer) (2.36) (0.38) (1.17) (2.11) (2.52) a Numbers in the parentheses are the standard deviations. ABC Different letters within the same row are significant (P < 0.05). 
UK Shrink Tank Study 

Water Temp 

205 200 195 195 212 200 195 195 202 206 195 201 202 207 210 

Time (sec) 

30 30 30 30 30 30 30 30 60 60 60 60 60 60 60 

210 60 

Appreciation expressed 

Don L. Zink, Ph.D. 

Office of Plant and Dairy Foods and Bev

Center for Food Safety and Applied Nu

Food and Drug Administration 

Alkar