INTRODUCTION Several method of employed for preservation and extension of self life of fish ranging from primitive drying/smoking to freezing and freez drying. Another important step forward is the development of technology for transportation of live fish. A notable and conceptual difference from all these method is utilization of ionizing radiation for food preservation. Preservation of foods using ionizing radiation is called irradiation. Preservation of food by irradiation is on of the truly peaceful uses of atomic energy irradiation of foods has been found useful and effective to: • Inhibit sprouting or reducing weight losses in vegetable such as potato, onion etc. during storage. • Delay the ripening of fruits. • Kill insect pests in fruits, grains or spices. • Reduce or eliminate food spoiling microorganisms in meat and seafood products.

1. IRRADIATIONOF FISHERIES PRODUCTS
Ashish sahu

2. CONTENTS
Introduction
History of food irradiation
Use of food irradiation
Principle of Irradiation
Unit for measuring irradiation
Types of Irradiation
Food Irradiation safety
Application
Advantage
Limitation
Reference.

3. INTRODUCTION
 Food irradiation is the process by which foods (such as
fishery products fruits, vegetable spices and meat) is
exposed to ionizing radiation to destroy
microorganisms, bacteria, viruses, or insects that might
be present in foods.
 It is the physical treatment that consists of exposing
foods either prepackaged or in the direct action of
electronic, electromagnetic rays.
 Food Irradiation is a form of food preservation that
prolong shelf life, improve microbiologic safety.

4. History of Irradiation in Food Preservation
1905 Begins the era of food
irradiation.
1980 Foods irradiated up to 10 kGy
considered to be safe and
wholesome.
2001 Irradiation is used to eliminate
possible traces of Anthrax.
1984-2009 FDAApproves the use of
Irradiation in a variety of foods.
Oldest
methods
Newer
methods
Drying
Pesticid
es
Preaser
vation
Refriger
ation
Salting
Canning
Freezing
Fermenting
Smoking
fresh frozen or
cooked products
Physical safe
Environme-
ntally clean
Efficient
technology

5. Why we irradiate foods ?
 Irradiation prevent food poisoning by killed
pathogenic bacteria such as E.coli(Fish ),
Campylobacter, Salmonella,(poultry)Clostridium
botulinam.
 It control insects and parasite infestation.
 It reduce by spoilage by destroyed mold,
bacteria and yeast.
 Increases shelf life of fishery products.

6. Food Irradiation Uses
Reduce insect infestation – fish an fishery products.
Inactivate parasite – fish and Vegetable.
Eliminate spoilage microbes – food .
Extend shelf life - Fish, Shellfish, poultry, meat.
Decontaminate - microbe.
Sterilize - food and feeds.

7. Principle of Irradiation
The energy employed in food Irradiation technology is referred
to as ionizing irradiation. Ionizing radiation occurs when one
or-more electron are remove atom. If enough energy is
transferred to an- orbital electron.
Methodof action
 E-Beam– shallow
penetration
 Converted to x-ray for
more penetration.
 Gamma – ‘deeper’
penetration
 All act via similar
mechanisms
Sources of radiation
Radionuclide or radioactive
materials that give off ionizing
gamma rays
1. Cobalt 60- 1.33 MeV
2. Cesium 137-662 KeV
Machine source of ionizing radiation
1. Electron accelerators operated at 10
MeV Or Less
2. X-ray generation at 7.5 MeV or less

8. IONIZING RADIATION
 Exists in form of waves.
 Shorter wavelength= greater energy
 Causes disruption of internal metabolisms of cells by
destruction of chemical bond.
Action of
Ionizing
Irradiation
Direct
Chemical events as a results
of energy deposition on
largest molecule.
indirect Radicals formed from the
radiolysis of water.

9. UNITSFORMEASURINGRADIATION
There are two types of units for measuring radiation
1. Intensity:
 The intensity refers to the source
 The intensity of a radioactive source is measured in number of disintegrations
per second.
 The unit of intensity is the curie(which represents 3.7x100
1Ci= 3.7 x 100Bq= 37GBq
2. Dose
 The dose refers to the products
 The treatments received by the food product is characterized the radiations
dose, the quantity of energy absorb by the food while it is exposed to the
radiation field.
 The units of dose is the gray (Gy).

10. Dosimetry:-
Measuring the irradiation dose is known as Dosimentry
In Irradiation processing of foods, the doses are generally measured
in kilograys (kGy,= 1,000Gy).
Low dose applications (Upto 1kGY)
Control insects
Inhibited maturation
Inhibits sprouting
Medium dose applications (1kGy to 10 kGy)
Extend shelf life
Reduce microorganism level
High dose applications above (10kGy)
Sterilize analogous to canning
Decontaminate certain food additives, e.g, fishery products ,spices etc.

11. Types of irradiation in food processing
1. Accelerated electrons
2. Gamma rays
3. X-rays
1. Accelerated electrons
 The electron beam is a stream of high
energy electrons, propelled out of an
electron gun. There are no radio active
materials in the process.
 Produced by linear accelerators.
 It has low dose radiation.
 It is portable (no reactor required)
 Advantage is shorter exposure time.

12. 2. X-rays
 X-ray machines having a maximum energy of five
million electron volts (MeV)
 Products during high energy collisions of gamma rays
and heavy elements (i.e. Tungsten)
 Little practical applications because of low
conversion efficiency of gamma to X-rays.
3. Gamma Radiation
 Most widely used type of ionizing radiation.
 Cobalt-60 specifically manufactured, for
radiotherapy, medical device sterilization and food
irradiation, not a waste product of nuclear reactors.
 The radiation is obtained through the use of radio
isotrops.

13. Irradiation facilities
Gamma source

14. Effects on Microorganisms and Food Components
 Affects microorganisms, such as bacteria, yeast, and molds
 Causing lesions in the genetic material of the cell effectively preventing it from
carrying out the biological processes necessary for its continued existence.
. Effects of Irradiation on Food Components
Effects of
Irradia- tion
vitamins Lipids
CHO
Enzymes
Protein

15. FoodIrradiation - Safety
1. Radiologic and toxicological safety:
 Neither the food nor the packaging become radioactive
 No concern for unique radiolytic products (FDA).
 Animal feeding studies since 1950 with metabolic, reproductive ,
teratogenic, mutagenic end points.
2. Nutritional Adequacy
 Changes similar to those of cooking, canning, pasteurizing, heat
processing.
 Vitamin loss: Thiamine>vitamin C, B6>B2>Niacin.
 CHO and proteins relatively irradiation-resistant.
 Fats can be oxidized rancidity, odour changes.

16. 3. Microbiologic safety
 Viruses, spores, are resistant to radiation.
 Gram(-) spoilage bacteria more susceptible than pathogenic bacteria.
 Increase in mycotoxin after irradiation
 Radiation resistance and mutational changes.
Radura symbol

17. Application
The maximum recommended dose for foods is
10 – 15 KGy.
Control of ripening
Inhibition of sprouting
Sterilization
Reduction of pathogens
Dis-infestation
Shelf life
Extension
Decontamination
Product Quality
Improvement

18. ADVANTAGES OF IRRADIATION
 There is little or no heating of the
food and therefore negligible change
to sensory characteristics.
 Packaged and frozen foods may be
treated.
 Fresh foods may be preserved in a
single operation and without the use
of chemical preservation.
 Extended shelf life of some
products.
 Reduced risk of food-borne diseases
caused by microorganisms.
Minimize Food losses
and food spoilage
Improves Public
Health
Increase International
trade
Increase Energy
Saving

19. LIMITATIONS
Irradiation cannot be used for all foods:
 Egg and some Shell Fishes
 Dairy products
 Peaches
 Nectarines

20. REFERENCE
Post-harvest Technology of Fish and fish
products.[written by K. K. Bala Chandra]page
number 325-329.
Internet.
www.fpt.pdf.org
WWW. Food irradiation technology.
https://dae.nic.in.