Post on 02-May-2018
Antimicrobial Agents to Control Listeria monocytogenes Listeria monocytogenes.
A d L Milk ki PhDAndrew L Milkowski PhDAdjunct ProfessorMuscle Biology LaboratoryUniversity of Wisconsin - Madison
Food Research InstituteUniversity of Wisconsin-Madison
TopicsWhy use antimicrobials
Topics
Lactate/Diacetate
Antimycotics
Newer technologiesNewer technologies
Final thoughts
Food Research InstituteUniversity of Wisconsin-Madison
Preservative Methods to Reduce Foodborne
Prevent inadvertent contamination
Pathogen Risk*
Removal of contamination
• Thermal destruction by cooking
• Surface treatments at packaging
• Post-package pasteurization treatments
Inhibit G o thInhibit Growth* Adapted from Sofos, et al., 1998
Food Research InstituteUniversity of Wisconsin-Madison
What happens with no growth i hibit d L t i tiinhibitors and Lm contamination
Turkey Breast at 4CHam at 4C1.6% Salt, 75% Moisture, Sodium TripolyphosphatepH 6.2
2.5% Salt, 75% Moisture, Sodium TripolyphosphatepH 6.2
Food Research InstituteUniversity of Wisconsin-Madison
How can we inhibit growth of L t g i RTE t ?L. monocytogenes in RTE meats?
Extend the lag-phase or diminish the rate during log-phase of growth g g p g
Cured meatsNit it k th ff t i• Nitrite makes the effort easier
Uncured meatsUncured meats• More difficult to achieve
Food Research InstituteUniversity of Wisconsin-Madison
Lactate and Diacetate
• Most widely used Lm growth inhibitors in the US
• ~ 70% of RTE cured meats use this approach
Food Research InstituteUniversity of Wisconsin-Madison
Sodium and Potassium LactateSodium and Potassium Lactate
Weak acidsProduced from fermentation of sugarUsage level of 2 - 4% (of 60% solution) Slight salty flavorDis pts bacte ial memb ane pH g adients Disrupts bacterial membrane pH gradients Inhibits energy metabolismAntibotulinal agent Antibotulinal agent
Food Research InstituteUniversity of Wisconsin-Madison
Sodium DiacetateSodium Diacetate
Half neutralized vinegar a eut a ed egaDissociates into 40% acetic acid and 60% sodium acetateLower product pH due to presence of acetic acidU l l 0 10 0 15%Usage levels, 0.10 - 0.15%
Food Research InstituteUniversity of Wisconsin-Madison
Wh i bi ti d d?Lactate salts alone are only bacteriostatic
Why is a combination needed?y
at high concentrations (>3-4%)• Flavor quality impacted• Sodium?
S d d l lSodium diacetate alone only is bacteriostatic at high concentrations
Product stability impacted purge texture• Product stability impacted - purge, texture• Flavor quality impacted• Legal maximum in U S is 0 25%
Food Research InstituteUniversity of Wisconsin-Madison
• Legal maximum in U.S. is 0.25%
The Purac Opti Form® ModelDeveloped in 2001-2002
The Purac Opti.Form® Modelp
• Growth model• Factors – Salt, Product Moisture, Lactate, Diacetate• No cured model• No cured model
Updated in 2003• Boundary “time to failure” presentation
Refined – Expanded in 2007• Returned to a growth model
Added pH and temperature as inputs• Added pH and temperature as inputs• Includes cured and uncured predictions
Food Research InstituteUniversity of Wisconsin-Madison
Two Ham Scenarios at 4C Storage
2.5% Salt, 75% Moisture,2% Potassium Lactate14% sodium diacetate sodium tripolyphosphate.14% sodium diacetate, sodium tripolyphosphate
pH 6.2
2.5% Salt, 75% Moisture,2% Potassium Lactate.14% sodium diacetate, pH 5 8 pH 5.8
Food Research InstituteUniversity of Wisconsin-Madison
Two Uncured Turkey Breast Scenarios at Breast Scenarios at 4C Storage
1.6% Salt, 75% Moisture,2% Potassium Lactate14% Sodium Diacetate Sodium Tripolyphosphate.14% Sodium Diacetate, Sodium Tripolyphosphate
pH 6.2
1.6% Salt, 75% Moisture,2% Potassium Lactate.14% Sodium Diacetate, pH 5 8 pH 5.8
Food Research InstituteUniversity of Wisconsin-Madison
Ad t g f L t t /Di t tAdvantages of Lactate/DiacetateProven effective and reliableProven effective and reliableEasy to verifyRelative low costRelative low costTested with consumers and widely acceptedacceptedProtects vs. risk of contamination by consumer after package is openedconsumer after package is opened
Food Research InstituteUniversity of Wisconsin-Madison
Antimycotics•Benzoate
Antimycotics•Benzoate•SorbateP i t •Propionate
Food Research InstituteUniversity of Wisconsin-Madison
Control of Listeria on Cured Ham stored at 4°C (2.2% NaCl whole; 156 ppm nitrite, 75% moisture)
5Control
3
4
g C
FU/g
)
Na Benzoate 0.1%Na Propionate 0.2%K Sorbate 0.3%K Lactate 1.6% + Na Diacetate 0.1%
2
3
f Lis
teri
a (lo
g
0
1
Gro
wth
of
-12 4 6 8 10 12
C
Food Research InstituteUniversity of Wisconsin-Madison
15
Weeks at 4C Glass, et al, JFP 2007
Effect of benzoate, moisture, NaCl, Di t t L i d RTE tDiacetate on Lm in cured RTE meats
2.0% NaCl0.1% Na Diacetate
Seman et al., 2008 JFP 71:1386
Food Research InstituteUniversity of Wisconsin-Madison
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Differences from Glass et al, extended testing time to 18 wks; decrease NaCl
Other antimicrobialsFermentation & Fermentation Blends
Other antimicrobialsFermentation & Fermentation Blends• Danisco – MicroGARD™, NovaGARD™
• Kemin - SHIELD®
• Kerry – Alta®
• Purac - Verdad®
• WTI - Ional ®
Food Research InstituteUniversity of Wisconsin-Madison
Uncured Turkey Listeria Testing3.5 % VERDAD NV55 controls Listeria for 80 daysCompared to 26 days for Opti.Form PD4
8.09.0
10.0
6.07.0
2 log growth5.0
2.03.04.0
0 10 20 30 40 50 60 70 80 900 10 20 30 40 50 60 70 80 90
Days at 39°F/4°C
Control 2.5% Opti.Form PD4
Food Research InstituteUniversity of Wisconsin-Madison
3.5% Verdad NV55 4.5% Verdad NV55
Source: Courtesy of Purac America
Frankfurter Listeria TestingEffect of Verdad NV15 and NV55 on Listeria monocytogenes inEffect of Verdad NV15 and NV55 on Listeria monocytogenes in
frankfurter
7.00
5.00
6.00
g
2 00
3.00
4.00
Log
CFU
/g
0.00
1.00
2.00
0 20 40 60 80 100 120
Control 2% Verdad NV15 3% Verdad NV15
2% Optiform PD4 2% Verdad NV55 3% Verdad NV55
Food Research InstituteUniversity of Wisconsin-Madison
2% Optiform PD4 2% Verdad NV55 3% Verdad NV55
Source: Courtesy of Purac America
Surface Applied AgentsFlexibility
Surface Applied Agents
• Low Levels• Multiple possibilities
o Organic Acids, Spice Extracts, Bacteriocins Lauric Arginate…..
Equipment is available• USDA’s SLIC™ concept• RapidPak™ suface application during packagingp pp g p g g• Capital costs?
May help achieve Alternative 1 statusRequires ongoing verification/validationRequires ongoing verification/validationNot easy to do on sliced products• Slicing speed• Surface area to cover
Food Research InstituteUniversity of Wisconsin-Madison
Surface area to cover
Resources for InformationAcademia
Resources for InformationAcademiaSuppliersUSDA Directive 7120 1USDA Directive 7120.1FDA GRAS notices• http://www accessdata fda gov/scripts/fcn/fcn• http://www.accessdata.fda.gov/scripts/fcn/fcn
Navigation.cfm?rpt=grasListing
Food Research InstituteUniversity of Wisconsin-Madison
Lm Growth Inhibitors, Regulations d P bli H lthand Public Health
Do not change likelihood of Listeria Do not change likelihood of Listeria contamination in products
Do not kill Listeria
By inhibiting growth expect less likelihood of related Listeriosis of related Listeriosis
Food Research InstituteUniversity of Wisconsin-Madison
Listeria Growth InhibitionListeria Growth Inhibition
8.00
Predicted Log Counts/gm
Listeria Growth InhibitionEstimated Benefit to Public Health*
Listeria Growth InhibitionEstimated Benefit to Public Health*
7.001/7,500 risk
5.00
6.00
3.00
4.00
1/75 MM risk
1.00
2.00
1/50 B risk
Food Research InstituteUniversity of Wisconsin-Madison
*Based on Growth Model for 50 gm of RTE cured processed meat and median mortality riskfor neonates published by FDA/USDA Fall 2003 Listeria monocytogenesRisk Table IV-12 and Figure IV-7
SummarySummaryEnvironmental monitoring and preventative
i t i t ti h equipment interventions or process changes that minimize contamination in finished product
PLUS
Listeria Growth inhibitors in productListeria Growth inhibitors in product
EQUALSQ
Effective reduction in Lm risk
Food Research InstituteUniversity of Wisconsin-Madison
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