Heat is an inefficient sanitizer because it takes so much energy. The efficiency of heat
depends on the humidity, the temperature required, and the length of time it takes to
destroy microbes at that temperature. Heat destroys microorganisms if the temperature is high enough for long enough and if the design of the equipment or plant allows the heat to reach every area. Cleaning staff should use accurate thermometers to measure temperatures during cleaning to make sure that equipment and surfaces are
properly sanitized. Steam and hot water are the most common types of heat used for
sterilization.
Steam
Sanitizing with steam is expensive because of high energy costs, and it is usually ineffective. Workers often mistake water vapor for steam, so the temperature usually is not
high enough to sterilize the equipment or surface. Steam can make bacteria and soil
cake onto the surface so that the heat does not reach the microbes; then they stay alive.
Hot Water
Immersing small components (such as knives, small parts, eating utensils, and small
containers) into water heated to 82°C (l80°F) or higher is another way to sterilize
using heat. Pouring hot water into containers is not a reliable way to sterilize, because it is difficult to keep the water hot enough for long enough. Hot water can sanitize food-contact surfaces, plates, and utensils, although spores may survive more
than an hour of boiling temperatures.
The time needed to sterilize an item depends on the temperature of the water. If
equipment or surfaces are sterilized at a lower temperature, they must be kept at that
temperature for longer. If they will be sterilized for a shorter amount of time, the
temperature must be higher. This is known as a "time-temperature relationship."
Examples of times and temperatures used for sterilization are 15 minutes of heat at
85°C (l85°F), or 20 minutes at 82°C (l80°F). The volume of water and how fast it is
flowing can determine how long it takes for the item being sterilized to reach the
right temperature. Hot water is readily available and is not toxic. To sanitize equipment, water can be pumped through it while it is still assembled, or it can be immersed in water.
RADIATION
Radiation in the form of ultraviolet light or high-energy cathode or gamma rays destroys microorganisms. For example, hospitals and homes may use ultraviolet light
from low-pressure mercury vapor lamps to destroy microorganisms. Ultraviolet units
are already used in Europe and are starting to be used in the United States to disinfect water for drinking and food processing. Generally, the food industry uses radiation to destroy microorganisms in and on fruits, vegetables, and spices; trichina in
pork; and Salmonella in poultry. It does not work very well in food plants and foodservice facilities because the light rays must actually hit the microorganisms and only
kill microbes that are very close by. Some bacteria are more resistant to radiation and
need a longer exposure for the radiation to destroy them. Dust, grease, and opaque
or cloudy solutions absorb radiation and prevent it from killing microbes.
Answers & Comments
Answer:
Heat, Steam, Hot Water, Radiation
Explanation:
HEAT
Heat is an inefficient sanitizer because it takes so much energy. The efficiency of heat
depends on the humidity, the temperature required, and the length of time it takes to
destroy microbes at that temperature. Heat destroys microorganisms if the temperature is high enough for long enough and if the design of the equipment or plant allows the heat to reach every area. Cleaning staff should use accurate thermometers to measure temperatures during cleaning to make sure that equipment and surfaces are
properly sanitized. Steam and hot water are the most common types of heat used for
sterilization.
Steam
Sanitizing with steam is expensive because of high energy costs, and it is usually ineffective. Workers often mistake water vapor for steam, so the temperature usually is not
high enough to sterilize the equipment or surface. Steam can make bacteria and soil
cake onto the surface so that the heat does not reach the microbes; then they stay alive.
Hot Water
Immersing small components (such as knives, small parts, eating utensils, and small
containers) into water heated to 82°C (l80°F) or higher is another way to sterilize
using heat. Pouring hot water into containers is not a reliable way to sterilize, because it is difficult to keep the water hot enough for long enough. Hot water can sanitize food-contact surfaces, plates, and utensils, although spores may survive more
than an hour of boiling temperatures.
The time needed to sterilize an item depends on the temperature of the water. If
equipment or surfaces are sterilized at a lower temperature, they must be kept at that
temperature for longer. If they will be sterilized for a shorter amount of time, the
temperature must be higher. This is known as a "time-temperature relationship."
Examples of times and temperatures used for sterilization are 15 minutes of heat at
85°C (l85°F), or 20 minutes at 82°C (l80°F). The volume of water and how fast it is
flowing can determine how long it takes for the item being sterilized to reach the
right temperature. Hot water is readily available and is not toxic. To sanitize equipment, water can be pumped through it while it is still assembled, or it can be immersed in water.
RADIATION
Radiation in the form of ultraviolet light or high-energy cathode or gamma rays destroys microorganisms. For example, hospitals and homes may use ultraviolet light
from low-pressure mercury vapor lamps to destroy microorganisms. Ultraviolet units
are already used in Europe and are starting to be used in the United States to disinfect water for drinking and food processing. Generally, the food industry uses radiation to destroy microorganisms in and on fruits, vegetables, and spices; trichina in
pork; and Salmonella in poultry. It does not work very well in food plants and foodservice facilities because the light rays must actually hit the microorganisms and only
kill microbes that are very close by. Some bacteria are more resistant to radiation and
need a longer exposure for the radiation to destroy them. Dust, grease, and opaque
or cloudy solutions absorb radiation and prevent it from killing microbes.
Source: https://link.springer.com/chapter/10.1007%2F978-1-4615-6045-6_6