Interventions to improve microbial safety

– Compounds, Ingredients, Processes1. Carcass washing - remove, reduce beginning

numbers– remove bacteria before they attach to meat surfaces

– a. hot water

– 95oC wash pre-chill

– ~90% of beef plants currently use hot water

– reduce E. coli O157:H7 and Salmonella

– will reduce spoilage organisms also but…most are picked up in post-chill processing

-recently approved phage for E. coli

b. organic acids

– approved since 1992– lactic or acetic acid most common– 1- 2% solution– especially effective if used after hot water spray - cells are

susceptible– complex mixtures also developed

peroxyacetic acid, hydrogen peroxide, octanoic acid, acetic acid = “Inspexx” (brand name); Inspexx 100 = poultry; Inspexx 200 = red meat (USDA approved)

– good for Salmonella, Staphylococcus sp, Listeria monocytogenes– however, E. coli is acid resistant

c. steam

– steam pasteurization– 6.5 - 8 seconds of steam under pressure

– raises carcass surface temperature to ~185oF

– followed immediately by cold water spray to prevent surface cooking

– kills 95 - 99% of bacteria

– steam vacuuming also developed to clean contaminated areas on carcasses - alternative to knife trimming

– effective for Salmonella sp, Listeria sp and E. coli O157:H7

d. tri-sodium phosphate– approved in 1994, first for poultry

– primary effect seems to be to prevent microbial cell attachment

– especially effective if combined with organic acid sprays

e. acidified sodium chlorite– citric acid plus sodium chlorite

– surface spray treatment

– primarily used for poultry but approved for red meat and being adopted

– is effective against virtually all microorganisms including E. coli O157:H7 which is acid resistant

2. Ingredients

a. sodium/potassium lactate – permitted at 3% (4.8% of commercial solution

which is 60% lactate)

– also seems to improve water retention, flavor and color

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Inhibition of Listeria in an Uncured Chicken Roll (stored at 40o F)

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Inhibition of Listeria in an Cured Frankfurter (stored at 40o F)

b. sodium diacetate– permitted at 0.25%: most often used with lactate

– diacetate = 1:1 sodium acetate : acetic acid

c. activated lactoferrin– discovered in 1939

– approved Jan, 2002 by USDA for meat applications and as GRAS substance by FDA in Oct, 2001 for other foods

– natural compound from milk found in blood, saliva, tears

– effective against ~ 30 pathogens including Salmonella, E. coli O157:H7

c. activated lactoferrin (continued)

– binds iron very, very tightly which may be how it inhibits bacteria --- would also function as antioxidant

– lactoferrin is a antimicrobial peptide– glycoprotein of ~ 700 amino acids

– recent research has isolated a peptide called PR-39 from pork white blood cells that is antimicrobial

– may be another natural antimicrobial

d. cetylpyridinium chloride

– quarternary ammonium compound

– lethal to Salmonella, E. coli and Listeria

– currently allowed for exterior package surfaces, plant surface sanitizer and to treat chilling solutions used to cool cooked products

– not yet approved by FDA or USDA for direct food use but approval is expected because

– has been used for over 40 years in products like mouthwash

e. dried plum products “prunes”

– 3% plum extract inhibits E. coli O157:H7, Salmonella, Listeria and Staphylococcus sp

– also helps retain moisture, and has antioxidant activity

– does not change flavor

3. Processing treatmentsa. Post-packaging pasteurization with heat

– 80 - 90oC for ~ 1 minute will greatly reduce pathogens and spoilage types

– most significant for Listeria due to post - cooking surface contamination– effects are very dependent on package arrangement

– single packaged franks

single rows

double rows

– need to be careful about product effects especially increased purge

Vs

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b. irradiation

– approved for poultry in 1992 and red meat in 2000

– clearly effective against all microorganisms

– gamma (radioactive source), electron beam (limited penetration), and X-ray sources

– minimal product change i.e. product retains “raw” characteristics

– must be labeled as irradiated

– not yet approved for multicomponent (processed meat products)

c. high pressure processing

– use of ~87,000 psi to kill bacteria by disrupting cell functions (enzymes, membranes)

– advantageous for both pathogen control and shelf life (spoilage)

– does not alter product --- retains “raw” characteristics

– Hormel currently utilizes high pressure for processed ham products, and “natural” products

– requires no special regulations or labeling

– typically a batch process done post packaging

4. Bacteriophages

– Highly specific for different bacterial strains

– Approved by FDA (2006) for use in foods including meat to reduce L. monocytogenes (Intralytix LMP-102™)

– Also received FDA approval (~2010) of a phage product (ECP-100™ ) for E. coli 0157:H7

– Recently, FDA GRAS approval for Salmonella (Salmofresh) (www.intralytix.com) – targeting poultry

– Currently developing phage for Clostridium perfringens