Extended Shelf life Chilled Foods and Sous-Vide

Processing

Phil MinerichVP Research & Development

Hormel Foods Corp.

Can it be done?

YES !!!!

However…..

Pasteurized Food Processes

Pasteurize > Cool > Package (Normal Kitchen)• Normal spoilage process

Pasteurize > Package > Cool (Refrigerated Soups)• Hot pack, spore growth concerns

Package > Pasteurize > Cool (Sous vide)• Vac-pack, spore growth concerns

Pasteurize to eliminate vegetative spoilage organisms, cool and maintain temperature control throughout shelf life

Understand the Science (risks)

Not talking about;• Retorted, shelf stable foods• High-acid, shelf stable foods• Cured, refrigerated foods

Talking about ‘extended’ shelf life, refrigerated, non-cured foods; either cooked, then packaged, or vacuum-packaged, then cooked (sous-vide)

Spore former

facultative anaerobe107.629.77.010.04.20.94Yesinia enterocolitica

facultative anaerobe109.446.45.010.05.00.96Vibrio vulnificus

facultative anaerobe111.041.010.011.04.80.94Vibrio parahaemolyticus

facultative anaerobe109.450.06.010.05.00.97Vibrio cholerae

facultative anaerobe118.050.010.09.84.00.85Staphylococcus aureus - toxin

facultative anaerobe122.044.625.010.04.00.83Staphylococcus aureus - growth

facultative anaerobe116.843.05.29.34.80.96Shigella spp.

facultative anaerobe115.241.48.09.53.70.94Salmonella spp.

facultative anaerobe113.031.310.09.44.40.92Listeria monocytogenes

facultative anaerobe120.944.66.59.04.00.95Escherichia coli (pathogenic strains)

anaerobe125.650.07.09.05.00.93Clostridium perfringens

anaerobe113.036.05.09.05.00.97Clostridium botulinum, non-proteolytic E, B, F

anaerobe118.450.010.09.04.60.93Clostridium botulinum, proteolytic A, B, F

micro-aerophilic113.086.01.59.54.90.99Campylobacter jejuni

aerobe131.039.218.09.34.30.92Bacillus cereus

facultative anaerobe107.631.84.010.04.00.94Aeromonas hydrophila

Oxygen Requirement

max. temp., °F

min. temp., °F

max. % Salt

max. pH

min. pH

min. aWPathogen

Limiting Conditions for Targeted Pathogens

C. botulinum Characteristics

Canned Foods ESL & Sous-Vide

<0.1-min @ 212 F>15-min @ 212 FSpore heat resistance

0.96

10%

4.6

98 F (37 C)

50 F (10 C)

Proteolytic A,B,F

Minimum aw for growth

NaCl conc. to prevent growth

Minimum growth pH

Optimum growth temp

Minimum growth temp

5%

5.5

0.97

77 F (25 C)

36 F (2.5 C)

Non-Proteolytic B,E,F

Time to Toxin vs. TemperatureNon-Proteolytic C. botulinum

C. botulinum Characteristics

Canned Foods Sous-Vide

0.1-min @ 212 F25-min @ 212 FSpore heat resistance

0.96

10%

4.6

98 F (37 C)

50 F (10 C)

Proteolytic A,B,F

Minimum aw for growth

NaCl conc. to prevent growth

Minimum growth pH

Optimum growth temp

Minimum growth temp

5%

5.5

0.97

77 F (25 C)

36 F (2.5 C)

Non-Proteolytic B,E,F

Target 6-log reduction

Audits International/FDA1999 U.S. Food Temperature Survey

Spore-forming Pathogens

Safety of Extended Shelf life Chilled Foods non-proteolytic C. botulinum

Temp/Time Cool Store Shelf life• 194°F 10 min. <50°F ≤ 37°F Not Stated

≤ 41°F ≤ 10 days≤ 50°F ≤ 5 days

≤ 50°F and pH <5.0 NaCl >3.5%aW <0.97

• Other combination of factors to give a 6-log reduction of non-proteolytic C. botulinum

UK Advisory Committee on the Microbiological Safety of Foods (ACMSF)

Sous Vide & Minimally Processed Chilled Foods

Temp/Time Cool Store Shelf life

French Regulations• 158°F 40 min. <50°F in 120 min. <=37°F 6 day • 158°F 100 min. 21 day• 158°F 1000 min. 42 day

Dutch Belgian Guidelines• 194°F 10 min. <=41°F 10-42 day

FDA Derived Safe Storage Time

°F °C

55 12.850 10.045* 7.241* 5.040 4.435 1.730 -1.1

* FDA Food Code recommended holding time and temperature

Days

1.72.44.07.07.5

19.5123.8

What’s Gone Right?

Hurdle Concept

Water activitypH

Water activitypHTemperaturePressurePlus meat-only, no root crops (onion, carrot, potato, mushroom, etc)

New Players Push the Limits

Stews, Chilis, Soupsand Sauces

With Veggies

Still No Wreck?

Multiple, Multiple Hurdles

Pre-washesPeeling to remove outer contaminantsVision sorting technologiesChemical / acid washes

In addition to traditional hurdlesAND, food science in product formulation

wash peel sort wash

Natural Antimicrobials

Live cultures• Lactobacillus vavaricus, Carnobacterium piscicola

Fermentates• Organic acids, peptides

Bacteriocins• Nisin, Natamycin, Pediocin

Enzymes• Lysozyme

Natural antioxidants• Rosemary extract

Natural extracts

Acids/Salts

AcetateLactatePropionateBenzoateOctanoic acidMonolaurinSorbateAscorbateCitrateGDL (Glucono delta Lactone)Phosphates (trisodium phosphates)Salt (NaCl or KCl)

Chemicals

Nitrite/NitrateSulfite or SO2

Smoking/PhenolsSodium metasilicatesAcidified sodium chloriteAcidified sodium nitriteBHA, BHT, TBHQ

Process Options

Traditional Thermal Processes• Retort, Steam, Hot Water

UHT plus aseptic fillingRadio FrequencyOhmicHigh Pressure ProcessingIrradiation

Concerns with Current Strategy

Sept, 2006 Bolthouse Farms Carrot Juice bot incidentFlorida, Georgia, CanadaFDA response: shelf stable processGMA response: form a committeeIndustry response: spoils to the survivorsRisk, category lost to consumers

Proposed FSO’s

VEGETATIVE FOOD BORNE PATHOGENS1 – 160° F hot fill – kills vegetative pathogens

NON-PROTEOLYTIC CLOSTRIDIUM BOTULINUM1 – Processing steps to target minimum 6-log spore reduction2 – Antimicrobials – prevent outgrowth of C. Bot.

PROTEOLYTIC CLOSTRIDIUM BOTULINUM1 – Significant intervention to reduce spore loads2 – Antimicrobials – prevent outgrowth of C. Bot.3 – Validation of raw material spore loads <3 MPN/g 4 – Distribution temperature control <50° F does not grow5 – TTI to validate temperature control <50° F