Transcript What do these food items have in common?

Would you eat a pizza
that had been exposed
to nuclear radiation?
Why Or
Why not?
Which foods are irradiated?
• Wheat flour – control of mold
• White potatoes – inhibit sprouting
• Pork – kill Trichinia parasites
• Fruit and Vegetables – insect control; increase
shelf life
• Herbs and Spices - sterilization
• Poultry – bacterial pathogen reduction
• Meat – bacterial pathogen reduction
What is food irradiation?
• Food irradiation is a preservation
technique in which food products
are exposed briefly to highenergy radiation to control
insects, mold, bacteria, and
spoilage.
How does irradiation work?
• During the irradiation process, food products
absorb radiation.
• The radiation breaks down the chemical bonds
found within the DNA of the food material and
any contaminating microbes or insects.
• Contaminating organisms are not able to repair
DNA and reproduce.
What are the sources of
radiation?
• Gamma Rays
– Utilize radiation given off by Cobalt 60 or Cesium
137
• Electron Beams
– Stream of high-energy electrons propelled from an
electron gun
– Similar to Beta Particles
• X-rays
– Electron beam is directed at a thin plate of gold (or
other metal), producing a stream of X-rays exiting
from the other side
Cobalt-60 Gamma
Irradiation Plant
Electron Beam/X-Ray
Irradiation Plant
How do radiation sources
compare?
• Gamma Radiation (Gamma Rays from Nuclear Decay)
– Good penetration
– Special Facility, Nuclear Waste
• Electron Beam (Like Beta Particles but Produced by Electricity)
– No Waste, In-line equipment
– New Technology
• X-Ray (Lower Energy Rays Produced by Electron Beam)
– No Waste, In-line equipment, Good Penetration
– Newest Technology
What changes occur in the
quality of irradiated foods?
• Irradiation is a “cold” process, and
therefore…
– Little if any change in physical appearance
• No textural or color changes as with traditional
heat preservation
• Possible chemical changes
– Off-flavors
– Tissue softening
What are the benefits?
• Irradiation…
–
–
–
–
–
Delays ripening
Inhibits sprouting
Controls insects
Reduces chemical residues
Reduces organisms which cause spoilage and
foodborne illness
– Extends the shelf life and improves safety of food
products
How do you know if your
food has been irradiated?
• Irradiation must be
indicated on the label of
all irradiated retail food
products
– “treated with radiation”
– “treated by irradiation”
Are irradiated foods safe?
YES!
Radiation doses are never large enough to
cause nuclear changes that would cause
the food material to become radioactive.
So, now would you eat an
irradiated food product?
Why
Or
Why not?