Time and temperature are two of the most important factors to control in the prevention of a food borne illness. There are many steps during the process of preparing and serving food in which time and temperature must be controlled. Harmful microorganisms grow well in foods held between temperatures of 41 degrees Fahrenheit and 135 degrees Fahrenheit. This temperature range is also known as the Temperature Danger Zone (TDZ). The less time foods spend in the TDZ, the less time harmful microorganisms have to grow. Typically harmful microorganisms can grow to levels high enough to cause illness within four hours; therefore specific regulations should be taken for prevention of a food borne illness focus on reducing the amount of time foods remain in the TDZ. The following sections outline the requirements of time and temperature control during the preparation and service of PHF.
Types of Potentially Hazardous Foods
Potentially hazardous foods are foods that might contain
food poisoning bacteria and are capable of supporting growth of these bacteria
or formation of toxins to levels that are unsafe for consumers, if the foods
are not stored at correct temperatures. Toxins are poisonous chemicals produced
by some types of bacteria.
The following are examples of potentially hazardous foods:
[Many types of foods can
become unsafe and cause people to become ill. Some foods, known as PHFs, are at
higher risk for growing harmful microorganisms; it is these microorganisms that
cause a food borne illness.
The following foods are
considered PHF and require proper control of time and temperature:]
·
Milk
and dairy products (Custard, desserts)
·
Eggs
·
Meat
(beef, pork and lamb) and Poultry
·
Fish
and shellfish
·
Baked
Potatoes
- cooked rice and pasta;
- Processed fruits and vegetables, for
example, salads; such as sandwiches and rolls.
·
Tofu
and other soy proteins and Sprouts and sprout seeds
·
Sliced
melons and cut tomatoes Or anything that is cutted or cooked
Cooking Potentially Hazardous Foods
In order to ensure that the
foods you are cooking have reached the proper internal temperature required to
reduce the potential for a food borne illness, two steps must occur. First, use
a thermometer to take food temperatures; and second, cook foods to the required
internal temperature for the specified length of time (see chart below):
Type of Food
|
Minimum Internal Temp
|
Time
|
Fruits and Vegetables
|
135 deg Fahrenheit
|
15 seconds
|
Grains (rice,
beans, pasta, potatoes)
|
135 deg Fahrenheit
|
15 seconds
|
Commercially
processed ready-to-eat foods (chicken nuggets, cheese sticks)
|
135 deg Fahrenheit
|
15 seconds
|
Roasts (beef,
veal, lamb)
|
145 deg Fahrenheit
|
4 minutes
|
Steaks/Chops
(beef, veal, lamb)
|
145 deg Fahrenheit
|
15 seconds
|
Ground meats
(other than poultry)
|
155 deg Fahrenheit
|
15 seconds
|
Eggs (hot
held for service)
|
155 deg Fahrenheit
|
15 seconds
|
Ham
|
155 deg Fahrenheit
|
15 seconds
|
Poultry (whole
or ground)
|
165 deg Fahrenheit
|
15 seconds
|
Reheated
Foods
|
165 deg Fahrenheit
|
15 seconds
|
Hot and Cold Holding of
Potentially Hazardous Foods
Foods that are not immediately served after cooking, which are
most commonly known as “held for service,” are at risk for time and temperature
abuse. Whether or not you have sources of heat or refrigeration to keep foods
within temperature range, it is important to monitor temperatures to prevent a
food borne illness. The following outlines the proper procedures for holding
PHF:
Hot Food
When a source of heat is available, hold hot foods at 135 degrees
Fahrenheit or higher and check the temperature every four hours. If the
temperature of the food at four hours is less than 135 degrees Fahrenheit, the
food must be discarded.
It is permissible to hold hot food without temperature controls
for up to four hours if the following conditions are met:
- Food must be held at 135 degrees Fahrenheit or higher
before the food is removed from the temperature control.
- Label
the food upon receipt with the time it must be discarded. The discard
time is four hours after the food has been removed from the temperature
control.
- After the four-hour time limit, the food must have been served, consumed, or
thrown away.
Cold Food
Hold cold foods at 41 degrees Fahrenheit or less and check the
temperature every four hours. If the temperature of the food at four hours is
greater than 41 degrees Fahrenheit, the food must be discarded.
It is permissible to hold cold food without temperature controls
for up to four hours if the
following conditions are met:
- Cool
Food must be held at 41 degrees Fahrenheit or less before the food is
removed from the temperature control.
- Label
the food upon receipt with the time it must be discarded. The discard
time is four hours after the
food has been removed from the temperature control.
- After the four-hour time limit, the food
must have been served, consumed, or thrown away.
Which foods are not potentially hazardous foods?
Many
preserved foods do not contain food poisoning bacteria. Also, bacteria will not
grow in some types of food. Examples include canned and bottled food, dried
fruit, salted dried meats, fermented dried meats, yoghurts, hard cheeses,
spreads, some sauces, dried pasta, breads and dried foods.
However,
some foods that are not potentially hazardous can become potentially hazardous
if you alter the food in some ways. For example, dry custard powder is not
potentially hazardous but when milk or water is mixed with the powder to make
custard, the custard is potentially hazardous.
Some
foods may not be potentially hazardous but need refrigeration to stop them from
spoiling. It is an offence to sell spoiled food.
When must food be kept under temperature control?
You
must ensure that the temperature of potentially hazardous food is either at 41°F/5°C
or colder or at 60°C or hotter when it is received, displayed, transported or
stored. If you want to receive, display, transport or store potentially
hazardous food at another temperature, you must be able to show an enforcement
officer that you have a safe alternative system in place.
You do
not have to keep potentially hazardous food at any specified temperature when
you are processing or preparing it because that would be impractical, but you
must keep the processing or preparation time as short as possible so that
bacteria do not get a chance to multiply to dangerous levels or form toxins.
Cooling potentially hazardous food
If you
cook potentially hazardous food that you intend to cool and use later, you need
to cool the food to 41°F/5°C or colder as quickly as possible. There may be
food poisoning bacteria in the food even though it has been cooked. Faster
cooling times limit the time when these bacteria are able to grow or form
toxins.
The
standards require food to be cooled from 145°F/60°C
to 70°F/21°C in a maximum of two hours and from 70°F/21°C to 41°F/5°C within a further maximum period of four hours.
Alternatively, if you want to cool food over a longer time period you must be
able to show that you have a safe alternative system in place.
If you
don’t know how fast your food is cooling, use a probe thermometer to measure
the warmest part of the food – usually in the centre.
To chill food quickly;
divide it into smaller portions in shallow containers. Take care not to
contaminate the food as you do it.
Reheating previously cooked and cooled potentially
hazardous food
If you
reheat previously cooked and cooled potentially hazardous food, you must reheat it rapidly to 135°F/60°C or
hotter. Ideally, you should aim to reheat food to 135°F/60°C within a maximum
of two hours to minimise the amount of time that food is at temperatures that
favour the growth of bacteria or formation of toxins.
This
requirement applies only to potentially hazardous food that you want to hold
hot, for example, on your stove or in a food display unit. It does not apply to
food you reheat and then immediately serve to customers for consumption, for
example, in a restaurant or a take away shop.
