Lecture 6 Flashcards

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1
Q

What is ionizing Radiation?

A

Radiant energy with some penetrating power which do not produce radioactivity in treated foods

-Need penetrating power for food irradiation

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2
Q

What is cold pasteurization?

A

Radiation of food does not produce significant heat in foods

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3
Q

What is the relationship between wave frequency, penetrating power and wavelength?

A

Higher frequency, higher penetrating power and lower the wavelength

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4
Q

What can UV lights do to food?

A

Inactivate microorganisms on the surface of foods (meats)

Wave lengths from:13.6-400

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5
Q

Are x rays used to irradiate food?

A

No, currently at the experimental

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6
Q

Do alpha beta and delta wavelengths help with irradiation?

A

α Particles: Helium (He) atom minus 2 Electrons (Low Penetration)

β Particles: High Energy Electrons

δ Rays: Strong Penetration Power

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7
Q

In 1985 what did the FDA allow for irradiation?

A

Strawberries
Poultry
Ground Beef
Pork

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8
Q

Is irradiation a type of food preservation?

A

Yes because in the process you are destrouing the spoilage and mircooragnisms and therefor extrending the shelflife of the food

Onion and potato for sprout preveention
Consumer demand isnt high in canada so its not sold, people sitill concerned about safety

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9
Q

What are the 3 main thing irradiation is used for?

A

Control Insects in Foods and Spices

Inhibit Sprouting

Destroy Vegetative Cells of Microorganisms
-Actively reeproducing cells without spores

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10
Q

What are the sources of ionizing radiation?

A

Natural Radioactivity

  • Uranium
  • -Breakdown of atomic structure produce radiation energy

Synthetic Radioactivity

  • Cobalt – 60
  • High energy bombardment of atoms

Flow of Electrons

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11
Q

What is a RAD?

A

Radient absorbed dose

-Is measure of ionizing energy absorbed

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12
Q

What RAD do we use for food?

A

Low = up to 1 KGY,
Med 1-10 KGY,
High = 10-50 KGY

Use low-med in food kilogray
High may get negative aspects of the process of irradiatioini

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13
Q

What are the different measures of RADs?

A
GRAY = 100 RADS
KRAD = 1000 RADS
MRAD = 1 000 000 RADS
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14
Q

What must foods that have used irradiation put on their labels?

A

Must carry the International Food Irradiation Symbol (RADURA)

Include a Written Statement:

  • Treated with Irradiation
  • Treaded by Irradiation
  • Irradiated
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15
Q

What are the factors important in food radiation?

A

1) Safety and Wholesomeness of the Treated Food
- Final orduct is safe for human consumption

2) Resistance of Food to Organoleptic Quality Damage
- ensory properties of the foods, depeends on chemical copm and structure of foods

3) Resistance of Microorganisms
- C bot is the most reesisitant sporre former

4) Resistance of Enzymes
- 20mrad to destroy because are very resistant

5) Cost
Higher irradiaiton =higher costs

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16
Q

The commercial use of irradiation depends on what?

A

Demand for Benefits Provided

Competitiveness with Alternative Processes

Willingness of Consumers to Buy

17
Q

What are the applications of irradiation?

A

Increase shelf life

Pathogenic reduction

Disinfestation

18
Q

How does irradiation increase shelf life?

A

↓ # of Spoilage M.O. (~ 1-10 KGY)
i.e. Meat, Vegetables, Fruits

Inhibit Sprouting
i.e. Potatoes, Onions

↓ Rate of Ripening (~ 1 KGY)
i.e. Strawberries: Shelf-life↑ (5 days to 15 days

19
Q

How does irradiation lead to pathogenic reduction?

A

Enables the microorganisms that causes disease/sickness

Salmonella (poultry), Campylobacter …

Trichinella spiralis parasites
(Trichinosis in pork)

20
Q

How does irradiation lead to disinfestation?

A

Disinfestation (insects)

As an alternative to chemical fumigation
Grains, spices, fruits, vegetables

21
Q

What is the safety of irradiated foods on nutrients, toxins, carcinogenic substances and radioactivity ?

A

nutrients: Use low-med irradiation the nutrients arent affected signifiacntly
toxins: No toxinc produced

carcinogenic substances : No produced

radioactivity: Food doesn’t become radioactive

22
Q

What are the disadvantages of radiation?

A

Off-flavour and off-odour

Destruction of B vitamins

Degradation of protein and other nitrogen compounds

Production of ammonia, hydrogen gas, CO2, H2S

Rancidity of fats

Tissue softness of vegetables