Chapter 21: Current Trends in Food Preservation: Irradiation

Question 1

What is food irradiation? What kind of preservation method? What is food exposed to?

Answer 1

cold food preservation method in which food is exposed to high-energy electromagnetic waves

Question 2

How does food move in food irradiation?

Answer 2

from one end of a radiation field to another on a conveyor belt while electromagnetic waves pass through it

Question 3

What does irradiation kill?

Answer 3

killing insects, and microorganisms

Question 4

What does the FDA approve irradiation for?

Answer 4

– 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

Question 5

What does ionizing radiation cause? Is it a health hazard?

Answer 5

Ions, called free radicals

- No, since the increase of free radicals is no greater than what occurs with other food preservation methods

Question 6

Free radicals are unstable. What kind of changes can they create?

Answer 6

chemical changes that kill microorganisms and block some enzymatic reactions

Question 7

What kind of foods are damaged by irradiation?

Answer 7

Foods with living cells, such as alfalfa sprouts and oysters

Question 8

When food is irradiated, what is produced? Give examples.

Answer 8

• Radiolytic products

- Carbon dioxide, formic acid, glucose

Question 9

Is irradiation considered a food additive? Why?

Answer 9

• Yes

- since radiolytic products are produced in the food

Question 10

Are there nutritional changes due to irradiation? What is lowered? What is stable?

Answer 10

• Lowers vitamin B1 (thiamin)

- Proteins, carbohydrates, fats, minerals, and most vitamins remain stable

Question 11

When are gamma rays given off?

Answer 11

radioactive material that releases energy as unstable nuclei break down

Question 12

What sources do gamma rays come from?

Answer 12

sources that must be stored in specially developed underground storage units

Question 13

Name the 2 types of gamma rays used for food irradiation.

Answer 13

– Cobalt-60, the most common

– Cesium-137, a by-product of plutonium production

Question 14

What are electron beams/E-beams made of?

Answer 14

high-energy electrons or beta particles produced by electronic machinery

Question 15

Are E-beams or gamma rays more costly?

Answer 15

E-beams are more costly

Question 16

When is radiant energy present with electron beans?

Answer 16

Only present when machines are running

Question 17

What is the advantage of E-beams?

Answer 17

No radioactive material needs to be transported or dumped

Question 18

What is ultraviolet light used for? Why?

Answer 18

only for surface treatment because it

cannot penetrate food

Question 19

Do X-rays penetrate food? What can’t they do?

Answer 19

– penetrate food in varying degrees depending on the density

– cannot be focused easily

Question 20

Name the 3 units of energy.

Answer 20

• rad: amount of E absorbed by 1 g of material
• gray: 100 rads
• kilogray: 1 000 grays

Question 21

What does rad mean?

Answer 21

radiation absorbed dose

Question 22

Does irradiation increase the radioactivity in foods?

Answer 22

No

Question 23

Who regulates facilities using radioactive sources?

Answer 23

The Nuclear Regulatory Commission

Question 24

Name some FDA guidelines for controlling irradiation.

Answer 24

– All irradiated foods are tested before they are
sold
– Plans for production plants must be approved before building
– Production plants are inspected frequently once in operation

Question 25

What is group 1 in terms of irradiated product labelling? Do they require a label?

Answer 25

Wheat, wheat flour, spices, herbs, teas, white potatoes, and sprouts

Question 26

What is group 2 in terms of irradiated product labelling? Do they require a label?

Answer 26

Whole irradiated foods (meats, poultry, fruits, vegetables)
- Must have the radura symbol
– Must be labeled with the words “treated with radiation” or “treated by irradiation”

Question 27

What is group 3 in terms of irradiated product labelling? Do they require a label?

Answer 27

• Processed foods that contain whole irradiated foods as ingredients
• Soups, frozen entrees, pizza
• are not required to show the radura or any
  statement about irradiation

Question 28

The radura label is required only on packaging to ____

Answer 28

the firsit purchaser

Question 29

Meat and poultry industries are allowed to use another term instead of irradiation as long as specific processing treatment criteria are met. What is this term?

Answer 29

Electronically pasteurized

Question 30

Does irradiation destroy C. botulinum?

Answer 30

No, but the risk of botulism for irradiated food is no greater than for foods preserved by any other method