Transcript Providing Safe Food

The Flow of Food: An Introduction
5-1
Apply Your Knowledge: Test Your Food Safety Knowledge
1. True or False: Chicken held at an internal temperature of
125°F (52°C) has been temperature abused
2. True or False: Infrared thermometers are best for
measuring the internal temperature of food
3. True or False: When checking the temperature of a roast
using a bimetallic stemmed thermometer, only the tip of
the thermometer stem should be inserted into the product
4. True or False: A thermometer calibrated by the boilingpoint method must be set to 135°F (57°C), after being
placed into the boiling water
5. True or False: Washing and rinsing a cutting board
will prevent it from cross-contaminating the next
product placed on it
5-2
The Flow of Food
To keep food safe:

Prevent cross-contamination

Prevent time-temperature
abuse
5-3
Preventing Cross-Contamination
Create physical barriers between
food products:

Assign specific equipment to each type
of food

Clean and sanitize work surfaces,
equipment, and utensils after
each task
5-4
Preventing Cross-Contamination
Create procedural barriers between
food products:

Prepare raw meat, fish, and poultry and
ready-to-eat food at different times
(when using the same prep table)

Purchase ingredients that require
minimal preparation
5-5
Preventing Time-Temperature Abuse
This includes:
Minimizing the time food spends in
the temperature danger zone

Determining the best way to monitor
time and temperature

Making thermometers available

Regularly recording temperatures and
the times they are taken
Microorganisms survive and grow

The
Temperature
Danger Zone
5-6
Temperature-Measuring Devices
Bimetallic Stemmed Thermometer
Indicator Head
Calibration Nut
Holding Clip
Stem
Sensing Area
Dimple
5-7
Temperature-Measuring Devices
Thermocouples and Thermistors

Measure temperature through a metal
probe or sensing area

Display results on a digital readout

Often come with interchangeable probes
Immersion Probe
Surface Probe
Photos courtesy of Cooper-Atkins Corporation
Penetration Probe
5-8
Temperature-Measuring Devices
Infrared Thermometers

Used to measure the surface
temperature of food and equipment

Must be held as close to the product as
possible

Remove barriers between thermometer
and product

Follow manufacturers’ guidelines
Photos courtesy of Cooper-Atkins Corporation
5-9
Apply Your Knowledge: Pick the Right Thermometer
Which temperature-measuring device
should be used to check the following?
1
1.
2
2.
3
3.
4
4.
Internal temperature of a hamburger patty
Surface temperature of a steak
Internal temperature of a roast
Internal temperature of a large stockpot of soup
A. Infrared thermometer
B. Thermocouple
C. Bimetallic stemmed
thermometer
5-10
Calibrating Thermometers
Calibration

Adjusting a thermometer in order
to get an accurate reading
Two methods

Boiling-point method

Ice-point method
5-11
Calibrating Thermometers
Boiling-Point Method
11.
Bring clean tap water to a boil
2.
2
Submerge the sensing area of the
thermometer stem or probe in the
water for thirty seconds
3.
3
Hold the calibration nut and rotate
the thermometer head until it reads
212°F (100°C)
Note: The boiling point of water varies
depending upon your elevation
5-12
Calibrating Thermometers
Ice-Point Method
1. Fill a large
container
with crushed ice
and water
2. Submerge the
thermometer
stem or probe in
the water for thirty
seconds
3. Hold the calibration
nut and rotate the
thermometer head
until it reads 32˚F
(0˚C)
5-13
General Thermometer Guidelines
When using thermometers:

Keep thermometers and their
storage cases clean

Calibrate them regularly to
ensure accuracy

Never use glass thermometers
to monitor food temperature

Insert the thermometer stem or
probe into thickest part of product
(usually the center)

Wait for the thermometer reading to
steady before recording the temperature
of a food item
5-14
Apply Your Knowledge: Calibrate the Thermometer
Put the steps for calibrating a
thermometer in the proper order:
A Rotate the head of the thermometer
A.
until it reads 32F (0C)
B Submerge the sensing area of the thermometer
B.
stem or probe, and wait for the reading to steady
C Fill a container with crushed ice and clean tap water
C.
D Hold the adjusting nut with a wrench or other tool
D.
5-15