Editing Food irradiation (section)

==Process==
[[File:E-beam-x-ray-gamma-efficiency.jpg|200px|thumbnail|Efficiency illustration of the different radiation technologies (electron beam, X-ray, gamma rays)]]
{{further|Irradiation|Radiation chemistry|Induced radioactivity}}
The target material is exposed an external source of radiation. The radiation source supplies energetic particles or [[electromagnetic waves]]. These particles or waves collide with material in the target.  The higher the likelihood of these collisions over a distance are, the lower the [[penetration depth]] of the irradiation process is as the energy is more quickly depleted.

These collisions break [[chemical bonds]], creating short lived radicals (e.g. the [[hydroxyl radical]], the hydrogen atom and [[solvated electron]]s). These radicals cause further [[#Chemical changes|chemical changes]] by bonding with and or stripping particles from nearby molecules. When collisions occur in cells, [[cell division]] is often suppressed, halting or slowing the processes that cause the food to mature.

When the process damages [[DNA]] or [[RNA]], effective [[reproduction]] becomes unlikely halting the population growth of viruses and organisms.<ref name="FI"/> The distribution of the dose of radiation varies from the food surface and the interior as it is absorbed as it moves through food and depends on the energy and density of the food and the type of radiation used.<ref name=":024"/>

===Better quality===
Irradiation leaves a product with qualities (sensory and chemical) that are more similar to unprocessed food than any preservation method that can achieve a similar degree of preservation.<ref name="EPA-food-safety">{{cite web |url=http://www.epa.gov/rpdweb00/sources/food_safety.html |title=Radiation Protection-Food Safety |publisher=epa.gov |access-date=May 19, 2014 |url-status=dead |archive-url=https://web.archive.org/web/20150906171333/http://www.epa.gov/radiation/sources/food_safety.html |archive-date=September 6, 2015 }}</ref>

===Not radioactive===
Irradiated food does not become radioactive; only particle energies that are incapable of causing significant [[induced radioactivity]] are used for food irradiation. In the United States this limit is 4 mega [[electron volt]]s (MEV) for [[electron beam]]s and [[x-ray]] sources—[[cobalt-60]] or [[caesium-137]] sources are never energetic enough to induce radioactivity.  Particles below this energy can never be energetic enough to modify the [[Atomic nucleus|nucleus]] of the targeted atom in the food, regardless of how many particles hit the target material, and so radioactivity can not be induced.<ref name="EPA-food-safety"/>

===Dosimetry===
The radiation absorbed dose is the amount energy absorbed per unit weight of the target material. Dose is used because, when the same substance is given the same dose, similar changes are observed in the target material([[Gray (unit)|Gy]] or [[Joule|J]]/[[Kilogram|kg]]). [[Dosimeter]]s are used to measure dose, and are small components that, when exposed to [[ionizing radiation]], change measurable physical attributes to a degree that can be correlated to the dose received. Measuring dose ([[dosimetry]]) involves exposing one or more dosimeters along with the target material.<ref>{{cite web |url=http://www-pub.iaea.org/MTCD/publications/pdf/TRS409_scr.pdf |title=Dosimetry for Food Irradiation, IAEA, Vienna, 2002, Technical Reports Series No. 409 |access-date=March 19, 2014 |archive-date=March 3, 2016 |archive-url=https://web.archive.org/web/20160303220425/http://www-pub.iaea.org/MTCD/publications/pdf/TRS409_scr.pdf |url-status=live }}</ref><ref>K. Mehta, Radiation Processing Dosimetry&nbsp;– A practical manual, 2006, GEX Corporation, Centennial, US</ref>

For purposes of legislation doses are divided into low (up to 1 kGy), medium (1 kGy to 10 kGy), and high-dose applications (above 10 kGy).<ref name=":3" /> High-dose applications are above those currently permitted in the US for commercial food items by the FDA and other regulators around the world,<ref>{{cite web|url=http://nucleus.iaea.org/ifa/|title=Irradiated Food Authorization Database (IFA)|access-date=March 19, 2014|url-status=dead|archive-url=https://web.archive.org/web/20140319174736/http://nucleus.iaea.org/ifa/|archive-date=March 19, 2014|df=mdy-all}}</ref> though these doses are approved for non commercial applications, such as sterilizing frozen meat for [[NASA]] [[astronauts]] (doses of 44 kGy)<ref>{{cite web|url=http://www.cfsan.fda.gov/~dms/opa-fdir.html |title=U. S. Food and Drug Administration. Center for Food Safety & Applied Nutrition. Office of Premarket Approval. ''Food Irradiation: The treatment of foods with ionizing radiation'' Kim M. Morehouse, PhD Published in ''Food Testing & Analysis'', June/July 1998 edition (Vol. 4, No. 3, Pages 9, 32, 35) |date=March 29, 2007 |access-date=March 19, 2014 |url-status=dead |archive-url=https://web.archive.org/web/20070329051854/http://www.cfsan.fda.gov/~dms/opa-fdir.html |archive-date=March 29, 2007 }}</ref> and food for hospital patients.

The ratio of the maximum dose permitted at the outer edge (D<sub>max</sub>) to the minimum limit to achieve processing conditions (D<sub>min</sub>) determines the uniformity of dose distribution. This ratio determines how uniform the irradiation process is.<ref name=":024">{{Cite book|title=Food Processing Technology: Principles and Practices|last=Fellows|first=P.J.}}</ref>

{| class="wikitable"
|+Applications of food irradiation<ref name=":3" /><ref>{{Cite book|last=Xuetong|first=Fan|date=2018-05-29|title=Food Irradiation Research and Technology|publisher=Wiley-Blackwell|isbn=978-0-8138-0209-1}}</ref>
|
|'''Application'''
|'''Dose (kGy)'''
|-
| rowspan="4" |Low dose (up to 1 kGy)
|Inhibit sprouting (potatoes, onions, yams, garlic)
|0.06 - 0.2
|-
|Delay in ripening (strawberries, potatoes)
|0.5 - 1.0
|-
|Prevent insect infestation (grains, cereals, coffee beans, spices, dried nuts, dried fruits, dried fish, mangoes, papayas)
|0.15 - 1.0
|-
|Parasite control and inactivation (tape worm, trichina)
|0.3 - 1.0
|-
| rowspan="4" |Medium dose (1 kGy to 10 kGy)
|Extend shelf-life of raw and fresh fish, seafood, fresh produce
|1.0 - 5.5
|-
|Extend shelf-life of refrigerated and frozen meat products
|4.5 - 7.0
|-
|Reduce risk of pathogenic and spoilage microbes (meat, seafood, spices, and poultry)
|1.0 - 7.0
|-
|Increased juice yield, reduction in cooking time of dried vegetables
|3.0 - 7.0
|-
| rowspan="4" |High dose (above 10 kGy)
|Enzymes (dehydrated)
|10.0
|-
|Sterilization of spices, dry vegetable seasonings
|30.0 max
|-
|Sterilization of packaging material
|10.0 - 25.0
|-
|Sterilization of foods ([[NASA]] and hospitals)
|44.0
|}