KEYS TO FOOD SAFETY

HAZARD

CONTROL

Cook WPS Aw pH

pH/ temp

pH/ Aw

Time/ temp

Chill

Competitive Microbial Inhibition

Preservatives

pH minima for pathogen growth Clostridium perfringens 5.5

Clostridium botulinum all types

4.6

Vibrio vulnificus 5.0 Staphylococcus aureus (toxin) 4.6

Campylobacter 4.9 Escherichia coli 4.4

Shigella 4.9 Listeria monocytogenes 4.4

Bacillus cereus 4.9 Yersinia enterocolitica 4.2

Vibrio

Bacteria need water to grow.

However, its not as simple as % moisture

(water)

Aw Fresh meats, milk,

and veggies 0.99

Cured meats 0.95-0.97

Cake Icing and honey 0.75

Parmesan cheese 0.75

Aw minima for pathogen growth Clostridium botulinum type E 0.97 Clostridium

perfringens 0.94

Shigella & Yersinia 0.97 Bacillus cereus 0.93

Vibrio vulnificus 0.96 Clostridium botulinum type A/B 0.93

Escherichia coli 0.95 Listeria monocytogenes 0.92

Salmonella 0.94 Staphylococcus aureus (toxin) 0.88

Vibrio parahaemolyticus 0.94

WPS minima for pathogen growth

Clostridium botulinum type E 5% Clostridium perfringens 7%

Shigella & Yersinia 7-8 Bacillus cereus 10

Vibrio vulnificus 5 Clostridium botulinum type A/B 10

Escherichia coli 6.5 Listeria monocytogenes 10

Salmonella 8 Staphylococcus aureus (toxin) 10

Vibrio parahaemolyticus 10 WPS=water phase

salt (%)

Clostridium botulinum psychrotrophic

Listeria monocytogenes

pH 4.6 4.39 Aw 0.97 0.92 Salt (WPS) 5% 10%

Hurdle Barrier

Multiple Hurdles = Barrier

Hazards

Acid tolerant pathogens (E. coli O157:H7 and Salmonella)

Controls

Pasteurization (canning) Refrigeration (time) Ambient (time)

Not Hazards

Clostridium, Bacillus, Listeria monocytogenes

Controls

Spores wont germinate at low pH – universal Cb pH cutoff is 4.6; Lm rapid die off.

Hazards same as acid foods

Controls Kombucha tea is hot brewed (vegetative cell lethality)

Culture is added (competitive exclusions)

Fermentation pH

Water-kefir = same culture with sugar water or fruit water as substrate

oInhibit w/drying temp. o Sporeformers oCb (48C),

oCp (52C)

o Bc (max 55C)

o SA Toxins (48C)

oKill Vegetatives o (63C)(while moist!)

oPreserve with Aw o Crackable is low Aw