Editing Food irradiation (section)

===Treatment===
To treat the food, it is exposed to a radioactive source for a set period of time to achieve a desired dose. Radiation may be emitted by a radioactive substance, or by X-ray and electron beam accelerators. Special precautions are taken to ensure the food stuffs never come in contact with the radioactive substances and that the personnel and the environment are protected from radiation exposure.<ref name="sterigenics"/>
Irradiation treatments are typically classified by dose (high, medium, and low), but are sometimes classified by the effects of the treatment<ref>{{Cite journal |doi=10.1016/j.foodcont.2008.07.023|title=The RADURA-terminology and food irradiation|journal=Food Control|volume=20|issue=5|pages=526–528|year=2009|last1=Ehlermann|first1=Dieter A.E.}}</ref> ([[radappertization|radappertisation]], [[radicidation]] and [[radurization|radurisation]]). Food irradiation is sometimes referred to as "cold pasteurisation"<ref>{{cite web |url=http://www.ext.vt.edu/pubs/foods/458-300/458-300.html  |archive-url=https://web.archive.org/web/20070102010926/http://www.ext.vt.edu/pubs/foods/458-300/458-300.html |archive-date=January 2, 2007 |title=Cold Pasteurization of Food By Irradiation |url-status=dead |access-date=June 1, 2016 |df=mdy-all |author1=Tim Roberts |date=August 1998 }}</ref> or "electronic pasteurisation"<ref>''See, e.g.,'' The Truth about Irradiated Meat, CONSUMER REPORTS 34-37 (August 2003).</ref> because ionising the food does not heat it to high temperatures during the process, and the effect is similar to [[Pasteurization|pasteurisation]]. The term "cold pasteurisation" is controversial because the term may be used to disguise the fact the food has been irradiated and pasteurisation and irradiation are fundamentally different processes.{{citation needed|date=December 2022}}

==== Gamma irradiation ====
Gamma irradiation is produced from the radioisotopes [[cobalt-60]] and [[caesium-137]], which are produced by neutron irradiation of [[cobalt-59]] (the only stable isotope of cobalt) and as a nuclear [[fission product]], respectively.<ref name=":3" /> Cobalt-60 is the most common source of [[Gamma ray|gamma rays]] for food irradiation in commercial scale facilities as it is water-insoluble and hence has little risk of environmental contamination by leakage into the water systems.<ref name=":3" /> As for transportation of the radiation source, cobalt-60 is transported in special trucks that prevent release of radiation and meet standards mentioned in the Regulations for Safe Transport of Radioactive Materials of the International Atomic Energy Act.<ref name=":5">{{Cite web|url=http://foodirradiation.org/PDF/FIPA%20QandA.pdf|title=Food Irradiation Q and A|publisher=Food Irradiation Processing Alliance|date=2018-05-29|access-date=May 20, 2018|archive-date=November 15, 2017|archive-url=https://web.archive.org/web/20171115232907/http://foodirradiation.org/PDF/FIPA%20QandA.pdf|url-status=usurped}}</ref> The special trucks must meet high safety standards and pass extensive tests to be approved to ship radiation sources. Conversely, caesium-137 is water-soluble and poses a risk of environmental contamination. Insufficient quantities are available for large-scale commercial use as the vast majority of Caesium-137 produced in nuclear reactors is not extracted from [[spent nuclear fuel]]. An incident where water-soluble caesium-137 leaked into the source storage pool requiring [[Nuclear Regulatory Commission|NRC]] intervention<ref>{{cite web|url=https://www.nrc.gov/reading-rm/doc-collections/gen-comm/info-notices/1989/in89082.html|title=Information Notice No. 89-82: RECENT SAFETY-RELATED INCIDENTS AT LARGE IRRADIATORS|publisher=Nrc.gov|access-date=March 19, 2014|archive-date=June 14, 2018|archive-url=https://web.archive.org/web/20180614195340/https://www.nrc.gov/reading-rm/doc-collections/gen-comm/info-notices/1989/in89082.html|url-status=live}}</ref> has led to near elimination of this radioisotope.
[[File:Cobalt 60 stored under water when not in use.jpg|thumb|Cobalt-60 stored in Gamma Irradiation machine]]
Gamma irradiation is widely used due to its high penetration depth and dose uniformity, allowing for large-scale applications with high throughput.<ref name=":3" /> Additionally, gamma irradiation is significantly less expensive than using an X-ray source. In most designs, the radioisotope, contained in stainless steel pencils, is stored in a water-filled storage pool which absorbs the radiation energy when not in use. For treatment, the source is lifted out of the storage tank, and product contained in totes is passed around the pencils to achieve required processing.<ref name=":3" />

Treatment costs vary as a function of dose and facility usage. A pallet or tote is typically exposed for several minutes to hours depending on dose. Low-dose applications such as disinfestation of fruit range between US$0.01/lb and US$0.08/lb while higher-dose applications can cost as much as US$0.20/lb.<ref name="ozone"/>

==== Electron beam ====
{{See also|Electron beam processing}}
Treatment of electron beams is created as a result of high energy electrons in an [[Electron accelerator|accelerator]] that generates electrons accelerated to 99% the speed of light.<ref name=":3" /> This system uses electrical energy and can be powered on and off. The high power correlates with a higher throughput and lower unit cost, but electron beams have low dose uniformity and a penetration depth of centimeters.<ref name=":3" /> Therefore, electron beam treatment works for products that have low thickness.{{citation needed|date=December 2022}}
==== X-ray ====
[[X-ray|X-rays]] are produced by bombardment of dense target material with high-energy accelerated electrons (this process is known as [[bremsstrahlung]]-conversion), giving rise to a continuous energy spectrum.<ref name=":3" /> Heavy metals, such as [[tantalum]] and [[tungsten]], are used because of their high atomic numbers and high melting temperatures. Tantalum is usually preferred over tungsten for industrial, large-area, high-power targets because it is more workable than the latter and has a higher threshold energy for induced reactions.<ref>{{cite conference|url=http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/41/097/41097063.pdf|title=Radiation Processing with High-energy X-rays|conference=International Nuclear Atlantic Conference|date=2009|first1=Marshall R.|last1=Cleland|first2=Frédéric|last2=Stichelbaut|access-date=May 20, 2018|archive-date=July 12, 2018|archive-url=https://web.archive.org/web/20180712154713/http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/41/097/41097063.pdf|url-status=live}}</ref>  Like electron beams, X-rays do not require the use of radioactive materials and can be turned off when not in use. X-rays have high penetration depths and high dose uniformity but they are a very expensive source of irradiation as only 8% of the incident energy is converted into X-rays.<ref name=":3" />

==== UV-C ====
[[UV-C]] does not penetrate as deeply as other methods. As such, its direct antimicrobial effect is limited to the surface only. Its DNA damage effect produces [[cyclobutane]]-type [[pyrimidine dimer]]s. Besides the direct effects, UV-C also [[induced resistance|induces resistance]] even against pathogens not yet [[inoculation|inoculated]]. Some of this induced resistance is understood, being the result of temporary inactivation of self-degradation enzymes like [[polygalacturonase]] and increased expression of enzymes associated with [[cell wall]] repair.<ref name="Civello-et-al-2007">{{cite book |editor=Troncoso-Rojas, Rosalba |editor2=Tiznado-Hernández, Martín E |editor3=González-León, Alberto |title=Recent advances in alternative postharvest technologies to control fungal diseases in fruits & vegetables |chapter=UV-C technology to control postharvest diseases of fruits and vegetables | year=2007 | isbn=978-81-7895-244-4 | oclc=181155001 | page= | s2cid=82390211 | last1=Civello | first1=P. | last2=Vicente | first2=Ariel R. | last3=Martínez | first3=G. | last4=Troncoso-Rojas | first4=R. | last5=Tiznado-Hernández | first5=M. | last6=González-León | first6=A.}} [[CAB Direct (database)|CABD]] [http://www.cabi.org/cabdirect/abstract/20073244868 20073244868]{{Dead link|date=June 2021 |bot=InternetArchiveBot |fix-attempted=yes }}. [[AGRIS]] id [http://agris.fao.org/agris-search/search.do?recordID=US201300122523 US201300122523]{{Dead link|date=June 2023 |bot=InternetArchiveBot |fix-attempted=yes }}.</ref>