The Summit of Safe Food?

Safe Plates Module 5

Firefly owner John Simmons poses at his restaurant at 3824 Paradise Road in Las Vegas on Monday Nov. 18, 2013. (Bill Hughes/Las Vegas Review-Journal)

http://www.nbcnews.com/health/health-news/possible-food-poisoning-sickens-100-safety-summit-n91631

• On April 11, 2014, the Baltimore City received reports of illness from attendees

• Became ill between April 8 and April 10. The attendees suspected that lunch served on April 9 was the source of the illnesses.

• Follow up interviews found 216 became ill, onset time of 16 hours.

Symptoms:• Nausea• Abdominal cramps or pain• Diarrhea

What Happened?

Possible Cause & Why?Potential Causes:•Bacteria•Norovirus

Possible Reasons Why:•Food purchased from unsafe sources•Failure to cook food to correct temperature•Improper holding temperatures •Contaminated equipment•Poor personal hygiene

• Stool specimens from 22 ill individuals were tested 14 days later, toxins found in 4 people.

• Frozen chicken breasts, garlic, and demi glace ‐were cultured for Bacillus cereus and Clostridium perfringens

• C. Perfringens was the likely cause identified by public health.

What They Found

As reported, but not documented, by manager.•Precooked frozen chicken breasts were placed on sheet pans and thawed in a walk in cooler on April 8. Cooked the morning of April 9 and transferred to 2‐inch pans after cooking.•The Marsala sauce was prepared the morning of April 9 and used only for the April 9 lunch. Poured directly over the pans of cooked chicken breasts 1h 20 min before service. Transported to convention center. Held hot until service.

What Went Wrong?

Learning Objectives• Explain the difference between “spore” and

“vegetative” cell • Describe the sources, symptoms, and control of

Clostridium perfringens, Clostridium botulinum, and Bacillus cereus

• List the correct cooling requirement for TCS foods• Describe methods to achieve rapid cooling

Learning Objectives• List the procedures that can be used for Time

as a Public Health Control for TCS Food• Define temperature danger zone (TDZ)• Explain problems created by a Heat Stable

Toxin• List practices that create a “reduced oxygen

content”

Key Terms

• Spore • Vegetative cell• Temperature Danger Zone• Cooling rate• Core (internal) Temperature• Oxygen requirement• Heat stable toxin

Spore Formers• Some bacteria may be in vegetative or spore

form• Vegetative (live) cells can be killed by cooking

to proper temperature• Higher temperatures kill more bacteria faster

• Spores can survive and create big problems

Spores

• Similar to a “seed”• Resistant to heat• 165oF for 15 seconds will destroy vegetative cells,

spores will survive• Destruction of spores- pressure and high

temperatures required (240oF)• Spores can change to vegetative cells and grow rapidly

during cooling and produce toxin• Important to have rapid cooling to prevent growth

and toxin production

Clostridium perfringens

•Found in soil and animal intestines•Symptoms- severe abdominal pain, diarrhea•Foods- meats, poultry, products made with meat products (chili, stews, gravies)•Symptoms – onset time 12-18 hours•Control- proper holding temperatures, proper cooling

Bacillus cereus• Spore-forming bacteria found everywhere• Causes 2 types of gastrointestinal illness

1. Diarrhea• Caused by toxin mediated infection (bacteria infects the body

and makes toxin)

• Onset 6-15 hours

2. Nausea, abdominal cramps, and diarrhea• Foodborne intoxication (toxin present in food)

• Highly stable toxin, resistant to heat

• Onset is pretty quick

Bacillus cereus• Vomiting symptoms – cooked rice dishes• Diarrhea & nausea symptoms – cooked

vegetables, meat products• Control- proper cook, hold and cooling

– Monitor temperature during service & cooling– Proper equipment for hot holding food– Tip sensitive digital thermometers are best

Clostridium botulinum• Present in soil and water• Toxin produced can be fatal• pH 4.6 or lower, toxin not produced• Requires reduced or lack of oxygen• Symptoms- weakness, double vision, difficulty

swallowing, speaking• Control, use only commercially processed

canned goods, proper temperature control• Discard any damaged containers of canned

food

Temperature

• Temperature Danger Zone

• Check temperature

• Cooling

Cooling Rates- minimize time in TDZ

Keep TCS (temperature control for safety) foods @ 41oF or lower or

135oF or higher

Cooling• Cool TCS food from 135oF to 41oF or lower in 6

hours – Step 1: 135oF to 70oF within 2 hours (Fast growth of

pathogens)– Step 2: 70o F to 41oF within 4 hours

• If food is cooled to from 135oF – 70oF in less than 2 hours, you still have 6 total hours to reach 41oF

Cooling• If food has not reached 70oF in 2 hours, it must

be thrown out (discarded) or reheated to 165oF, used for immediate service, or cooled correctly

• Properly cooled food can only be kept for 7 days• Freezing stops the clock, restarts when thawed• Mixing older items with new items uses the older

date

• Depth heat must moveGreater depth= longer time

• Larger containers (slower)

• Small shallow containers (faster) –Ideally 2-3 inches deep

Factors Influencing Cooling

Factors Influencing Cooling

• Liquid vs solids – Liquids(broth) - fast – Solid (semi-solid e.g. Chili) – slow

• Air vs Water Cooling method – Air - slow cooling - good insulator– Water- faster cooling - good conductor

• Cool in ice water bath faster than air in cooler or freezer

Factors Influencing Cooling

Other Factors• Loosely cover containers during cooling• Stirring- increases cooling rate• Use ice paddle (clean and sanitary) prevent

contamination• Tumble chillers- tumble bags of food in chilled

water• Blast chiller

Best Procedures: Summary

• Place food in small shallow container• Place in ice water bath• Stir (ice paddle)• Monitor time and temperature with tip

sensitive digital thermometer

Other Options

• Addition of ice or cold water to recipe– Water left out of original recipe– Avoid cross contamination (ice or water)

Time as a Public Health ControlTCS food can remain without temperature control for up to 4 hours:•Must have written procedure before hand•Marked with start time•Start temp must be above 135oF or below 41oF•Discard after 4 hours•Can not reheat or re-cool•If food is monitored and doesn’t exceed 70oF, can be held for 6 hours

Reduced Oxygen Packaging• Sealed package without any air and no oxygen

passing through package– Sous Vide– Cook/Chill large batches for later use

• Must control Botulism risk (and Listeria) Keep at low temperature (also use pH < 4.6 or aw <.91)

• Have documented procedures and training• May apply for a variance, need HACCP

What’s your experience

Have you changed cooling practices at your restaurant to minimize food safety risks?

Case Study

Case Study

Quiz

According to the FDA Food Code, the ‘temperature danger zone’ is:a)45oF - 140oFb)41oF - 135oFc)45oF - 141oFd)None of the above

QuizWhich of the following is not an acceptable method of cooling food?

a)Dividing the hot food into smaller or thinner portions and place in refrigerator or freezer

b)Using an ice bath- transfer the food to a clean cold container and place the container in a large on that holds ice or ice and water

c)Placing hot food in shallow pans and leave at room temperature for initial cooling

d)Stirring or rotating food while it is cooling

Quiz

According to the FDA Food Code, Cooked TCS food should be cooled as follows:a) From 130oF to 60oF within two hours and then from 60oF to 41oF or colder within four hoursb) From 135oF to 70oF within two hours; from 70oF to 41oF or colder within four additional hoursc) From 135oF to 45oF within four hoursd) From 135oF to 40oF within eight hours

Summary• Bacillus and Clostridium are spore formers• Spores not killed at normal cooking

temperatures • Do not use non commercial canned products• Temperature abuse• Proper and rapid cooling is critical• Monitor temperatures and time