irradiation
TRANSCRIPT
ITM UNIVERSITY GWALIOR
DEPARTMENTOF FOOD TECHNOLOGY
under the guidance of
MS NIHARIKA THAKUR PRESENTED BY
Asst professor SOUMEE MANDAL
MSc FOOD TECH Ist SEM
What is food irradiation? Food irradiation is a form of food processing with a
limited number of kinds of radiant energy put togetheras ‘ionizing radiation’ ,that extends shelf life andreduces spoilage of food. Foods such as fruits,vegetables, spices and meats can be exposedto radiation to kill insects, moulds and micro-organisms.
It is used as a preservation method
History of food irradiation• US Army investigates use of irradiation to improve safety
and quality of troop diets in 1930
• Approved for potatoes by Canada in 1960
• 1963 First FDA approval for insect control in wheat flour
• 1983 FDA approved irradiation for controlling microbes
in spices
• 1985 FDA allowed uses of irradiation to strawberries
,poultry, beef & pork
Sources of radiation Electron irradiation- e¯ are accelerated close to the
velocity of light, have higher cross section thus do notpenetrate the substance more than few inches. Eg-beta particles.
X-ray irradiators are scalable and have goodpenetration, with the added benefit of using anelectronic source that stops radiating when switchedoff. X rays are photon radiation of high energyspectrum.
Food irradiation using Cobalt-60 is the preferredmethod by most processors, because the betterpenetration enables administering treatment to entireindustrial pallets or totes, reducing the need formaterial handling.
The radiation is obtained through the use ofradioisotopes, generally Cobalt-60 or, in theory,Cesium-137. Cesium-137 is recovered during therefinement of spent nuclear fuel.
Effects
Direct
Hits a specific target likebullet
Changes in color andtexture by directcollision
Not sufficient forexplaining radiationseffects.
Hits mainly microbesand enzymes
Indirect
High energy radiationshit water moleculesinstead
Formation of reactivehydrogen and hydroxylions
Oxidizing radicals alterthe molecular structure
Hits constituents inaqueous solution
applications This method of preservation prevents growth of food
poisoning bacteria, destroys parasite, and delaysripening of fruits and vegetables.
Further applications include sprout inhibition, delayof ripening, increase of juice yield, and improvementof re-hydration.
Sterilization induces prolonged shelf life, can be usedfor hospitals, military and space flights. It also controlsfood borne illness.
advantages Little or no heating of food
Can treat packaged or frozen foods
No chemicals used for preservation of fresh foods
Low energy requirements
Comparable change in nutritional value
High automation
Disadvantages gamma radiation cant be turned off/on, workers need
to be protected.
High capital costs
Possible development of resistant microbes.
Inadequate analytical procedures to detect irradiationin food
high radiation can result in radical ion formation .
Unit of radiation Electron volts = 1.6 * 10^ -19 joules, so 32.5 eV is
required to produce 1 ion pair in air.
Rad = 10 ^-6 joules absorbed/ gram of material
1 kGy = 100,000 rads
1 roentgen= 2.08 * 10^9 ions/ cm^3 of dry air understandard temp and pressure.
RADURA SYMBOL The symbol Radura was originally used as a symbol of
quality for food processed by ionizing radiation.
The central dot is the radiation source. - The two circlesegments ('leaves') are the biological shield to protectthe workers and the environment. - The outer ring isthe transport system, the lower half of it is shieldedfrom radiation by the biological shield and resemblesalso the loading area, the upper broken halfsymbolizes the rays hitting the target goods on thetransport system
ENDORSMENT
The wholesomeness and nutritional adequacy of irradiated food has been well established. It is approved by the international and national regulatory authorities including USFDA, FSANZ and FSSAI (PFA). Several reputed professional bodies including American Medical Association, Institute of Food Technologists, and American Nuclear Society have endorsed the utility, safety and benefits of radiation processing of food
Irradiation in India
In India radiation processing of food can beundertaken both for export and domestic markets. Forexport, food could be processed for shelf-lifeextension,and hygienization,. Recently, it has beenpossible to export famous Indian mango to USA usingthis technology.
Huge quantities of cereals, pulses, their products,fruits and vegetables, sea foods, and spices areprocured, stored, and distributed throughout thelength and breadth of the country. Radiationprocessing can be used for disinfestation and storageof bulk and consumer packed commodities for supplychain management and retail distribution.
bibliography https://www.msu.edu/course/fsc/229/Notes/Lecture%
2011.htm
http://www.nukejobs.com/food_irradiation.html
http://www.barc.gov.in/akruti-tp/atp_rpap.html
Microsoft Word - Articles for radio serial.doc
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