Chapter 21: Current Trends in Food Preservation: Irradiation Flashcards
What is Food Irradiation?
Is a cold food preservation method in which food is exposed to high-energy electromagnetic waves
How does Food Irradiation work?
Food moves from one end of a radiation field to another on a conveyor belt while electromagnetic waves pass through it
How does Irradiation Sterilize?
Irradiation sterilizes by killing insects, and microorganisms
What are the things the FDA approves irradiation for?
- Wheat and wheat flour - to reduce losses to insects and molds
- White potatoes to reduce losses from rapid sprouting in storage
- Spices and herbs - to lower the risk of contaminants
- Pork, poultry and beef - to destroy microorganisms that cause foodborne illness
Ionizing Radiation causes what?
Ionizing Radiation causes ions called Free Radicals to form when the radiation comes in contact with food products
The increase of Free Radicals with Ionizing Radiation is what?
The increase of free radicals is no greater than what occurs with other food preservation methods, so is not a health hazard
What are Free Radicals?
These ions are unstable and create chemical changes that kill microorganisms and block some enzymatic reactions
- Foods with living cells, such as alfalfa sprouts and oysters are damaged by irradiation
What happens when Food is Irradiated?
When food is irradiated, radiolytic products are produced
ie) They include carbon dioxide, formic acid and glucose
Irradiation is considered what?
Irradiation is considered a food additive since radiolytic products are produced in the food
What Macromolecules remain stable after Irradiation?
Proteins, carbohydrates, fats, minerals and most vitamins remain stable
Irradiation lowers what Vitamins levels/
Irradiation lowers Vitamin B1 (thiamin) levels
What are Gamma Rays?
Are given off by radioactive material that releases energy as unstable nuclei break down
- come from sources that must be stored in specially developed underground storage units
What type of Energy (Gamma Rays) is/are Used for Food Irradiation?
- Cobalt-60, the most common
2. Cesium-137, a by product of plutonium
What are Electron beams or E-beams?
made of high energy electrons or beta particles produced by electronic machinery; more costly than Gamma Rays
Radiant Energy is only present when?
Radiant Energy is only present when machines are running
What is the advantage of Electron or E-beams?
Their advantage is no radioactive material needs to be transported or dumped
What is Ultraviolet Light?
Is used only for surface treatment because it cannot penetrate food
What are X-rays?
penetrate food in varying degrees depending on the density, cannot be focused easily, involve technology still being improved
Units of Energy include…?
- Rad: or radiation absorbed dose, which is the amount of energy absorbed by 1 gram of material
- Gray: which equals 100 rads
- Kilogray: which equals 1000 rads
Approved irradiation dosage levels what..?
Approved irradiation dosage levels vary with the type of food being treated
Studies show what?
Studies show irradiation does not increase the radioactivity of foods
Food processing plants do what to prevent human exposure?
Food processing plants make frequent radiation checks as part of many steps taken to prevent human exposure
What d studies show about Irradiation?
Studies show irradiation does not increase the radioactivity of foods
Food processing plants make what?
Food processing plants make frequent radiation checks as part of many steps taken to prevent human exposure
- packaging materials approved for using with irradiation will not add toxins to foods
