Gamma Irradiation

Group 6

SHAHMILA A/P SHANMUGAM AN120225

KHAIRUL ANWAR BIN ROSLI AN120228

NUR ELLYNA BINTI YUSUF WOO AN120227

Overview

Principles of Operation

- How Gamma Rays

Work

- Gamma Dosage &

Application

- Gamma Irradiation

Facility

By: Khairul Anwar

Discussion

- Advantages &

Limitations

- Importance of Gamma

Irradiation & Future Trend

- Suitability of Food

- Conclusion

By: Ellyna

Introduction

- Food Irradiation

- Types of Food

Irradiation

- History of Food

Irradiation

- Gamma Irradiation

By: shahmila

Introduction

By: Shahmila

Objectives

• To discuss the basic principles and mechanisms of Gamma Irradiation on food processing and food preservation.

• To study the uses and applications of Gamma Irradiation.

• To examine the Malaysian food product that is suitable to use Gamma Irradiation technology.

Food Irradiation

Food irradiation (the application of ionizing radiation to food) is a technology that improves the safety and extends the shelf life of foods by reducing or eliminating microorganisms and insects. Like pasteurizing milk and canning fruits and vegetables, irradiation can make food safer for the consumer.

Irradiation

• Irradiation is the deliberate process of exposing an item to certain types of radiation energy to bring about desirable changes.

• Ionizing radiation is radiant energy that has the ability to break chemical bonds.

Types of Food Irradiation

Gamma Rays

- Obtained naturally from radioactive decay of Cobalt-

60 or Caeseium-137 - Uses photons

Electron Beams

- Machine generated - High energy electrons

emitted by accelerators - Range of electron is finite &

closely related to its energy

X-rays

- Machine generated - Distribute primary electron

beam over a target - Emits photons with broad

energy spectrum

History of Food

Irradiation

Gamma Irradiation

• Gamma irradiation is a physical means of sterilization or decontamination where products are exposed to gamma rays. The gamma rays, which are a form of electromagnetic radiation of very short-wavelengths, act as a source of ionizing energy that destroys bacteria and pests.

• The isotope Cobalt-60 is the most common source of gamma rays for irradiation processing.

• Gamma irradiation is known as a ‘Cold Process’ as the temperature of the processed product does not increase significantly. It is also a chemical free process that is not reliant on humidity, temperature or pressure and can be applied to packaged goods.

• A key characteristic of Gamma irradiation is the high penetration capability.

PRINCIPLE OPERATION OF GAMMA

IRRADIATION

By Khairul Anwar

How Gamma Rays Works?

• When gamma radiation passes through biological tissues such as foods, some of the energy of

the radiation is absorbed by food molecules.

• The gamma radiation initially interacts with food nutrients to produce reactive chemical

intermediates that are transient and disintegrate rapidly after exposure to ionizing radiation.

• The irradiation effects are due to the indirect action of these transient chemicals not by the direct

effect of the radiation itself.

• The primary mechanism in food irradiation that kills bacteria is through the splitting of water

molecules into hydrogen (H+), hydroxyl (OH-) and oxygen (O-2) radicals.

• Those radicals react with and destroy or deactivate bacterial components such as DNA, proteins

and cell membranes.

• Radiation also capable to damage or breaking large molecules such as DNA and enzymes that

prevent bacteria from replicating, destroy the pathogen population’s growth and effectively kill

germs in the food.

Example of gamma radiation on Strawberry

Exposing strawberry to the

gamma rays of Cobalt-60. Energy from gamma ray

passing through the strawberry is enough to destroy many pathogenic bacteria and

enzyme activities that cause the food to spoil.

The gamma radiation dosage given is not strong enough to change the quality, texture,

flavor and taste of the strawberry.

Effect of Radiation Dosage • The dose for food irradiation is the amount of radiation absorbed by the

food and it is not the same as the level of energy transmitted from the radiation sources.

• The dose is controlled by the intensity of radiation and the length of time the food is exposed.

• The FDA's regulations describe radiation levels in terms of the kilogray (kGy), equal to 1000 Gy. The dose (number of kGy) permitted varies according to the type of food and the desired action.

• Treatment levels are categorized by FDA as follows:

i. Low Dose Level (10 Gy to 1 kGy) – Radicidation

ii. Medium Dose Level (1 kGy – 10 kGy) – Radurization

iii. High Dose Level ( 10 kGy – 100 kGy) – Radappertization

Level Dosage of Gamma Radiation and The Application

• Efficiently eliminate pathogenic organisms including bacteria and parasites.

• E.g: Irradiating ground beef to make it safe from E. coli O157:H7

Pathogen Reduction

• High dose to eliminate all organisms so refrigeration is not required (shelf stable).

• E.g: Certain foods are sterilized for NASA astronauts and for immune-deficiency patient.

Sterilization

• Reduce organisms for spices, herbs and other dried vegetable substances

• E.g: Spice blends that are added to meat for hot dogs and other ready to eat products that may not be cooked again

• Delays ripening and/or sprouting

• E.g: Irridate potatoes, onions and garlic to impair cell division so that can delay sprouting

Sanitation

• Use to stop reproduction of both storage and quarantine insect pests.

• E.g: Irridate papayas & mangoes to eliminate fruit flies (quarantine pest) before export/import.

Disinfectant

Radiation Processing

Gamma Radiation Facility

• All commercial irradiators have four primary components:

A source of radiation.

A method of product conveyance.

“Shields” to prevent exposure of personnel.

The environment to radiation and safety systems.

• Gamma rays emitted spontaneously through the radioactive decay of Co-60 and Cs-137.

• Co-60 are the most used radioactive in gamma facility due to the deeper penetration and higher gamma ray energies.

Gamma Irradiator Device Model JS9600 (Registered by the International Atomic Energy Agency with serial number IR-185.)

Gamma Irradiation Device Model JS9600 (Registered by the International Atomic Energy Agency with serial number IR-185) consists of:

1. Process Control (Control Room) 2. Product Transportation System – pneumatic pistons and conveyor 3. Source and Source Rack – the sources where gamma rays sources stored 4. Irradiation Cell (Biological Shield) – where the irradiation process take place. 5. Source Storage Pool – excess radiation was stored to avoid leaking gamma rays. 6. Product Storage Area – storage area of processed and unprocessed product

Discussion

By: Ellyna

Advantages of food irradiation

Disease causing germs are reduced or eliminated

The nutritional value of food is preserved

Decreased incidents of food borne illness

Reduced spoilage in global food supply

Increased level of quality assurance in international trade of food products

Limitations of food irradiation

• Restricted to certain food types

Some foods, such as dairy foods and eggs, cannot be irradiated

because it causes changes in flavour or texture. Fruits, vegetables, grain foods, spices and meats (such as chicken) can be irradiated.

• Irradiation causes minimal changes to the chemical composition of the food

it can alter the nutrient content of some foods because it reduces the

level of some of the B-group vitamins

Food

Main objective

Means of attaining objective

Dosage, Mrad

Meat, poultry, fish and many other highly perishable foods

Safe long-term preservation without refrigerated storage

Destruction of spoilage organisms and

any pathogens present, particularly Cl. botulinum

a4 to 6

Meat, poultry, fish and many other highly perishable foods

Extension of refrigerated storage below 3° C

Reduction of population of

microorganisms capable of growth at these temperatures

0.05 to 1.0

Frozen meat, poultry, eggs, and other

foods, including animal feeds, liable to contamination with pathogens

Prevention of food- poisoning Destruction of Salmonellae b0.3 to 1.0

Meat and other foods carrying pathogenic parasites

Prevention of parasitic disease transmitted through food

Destruction of parasites such as Trichinella spiralis and Taenia saginata

0.01 to 0.03

Cereals, flour, fresh and dried fruit, and other products liable to infestation

Prevention of loss of stored food or spread of pests

Killing or sexual sterilization of insects 0.01 to 0. 05

Fruit and certain vegetables Improvement of keeping properties Reduction of population of molds and

yeasts and/or in some instances delay of maturation

0.1 to 0. 5

Tubers (e. g., potatoes), bulbs (e. g.,

onions) and other underground organs of plants

Extension of storage life Inhibition of sprouting 0.005 to 0.015

Spices and other special food ingredients Minimization of contamination of food to which the ingredients are added

Reduction of population of microbes in special ingredient

1 to 3

Types of food that can be irradiated

Importance Of Gamma Irradiation And Future Trend

• Public acceptance

The lack of acceptance of food irradiation has been mainly due to misconceptions and irrational fear of nuclear related technologies. Also, people are confused and fail to differentiate irradiated food from radioactive foods

• Commercial application

Good Manufacturing Practice (GMP) and associated Good Irradiation Practice (GIP) are now available for commercial application of the process

• Irradiation as an alternative for chemical fumigation

Irradiation of food is a physical method which unlike chemical fumigants does not leave residues on the products

• Improvement of public health standards

Elimination of the risk of pathogenic organisms that often contaminate such foods.

Conclusion

• Food irradiation can be used to combat foodborne diseases, including the emergence of disease causing organisms such as Escherichia coli, Campylobacter jejuni, and Listeria monocytogenes.

• Food irradiation is not a substitute for proper handling, cooking, and storage of food. Care must be taken to ensure that irradiated foods do not become decontaminated.

• Also, food irradiation could be used in place of harmful fumigants used to kill mold and insects on produce and grain.

References • Derr, D.D. 1993. International regulatory status and harmonization of food

irradiation. J. Food Protect. 56(10): 882-886.

• IAEA. 1995. Food Irradiation Newsletter. Supplement. Vol. 19(2), Intl. Atomic Energy Agency, Vienna, Austria. IFT. 1983. Radiation preservation of foods. A Scientific Status Summary by the Institute of Food Technologists’ Expert Panel on Food Safety and Nutrition, Chicago, Ill. Food Technol. 37(2): 55-61.

• CAST. 1986. Ionizing energy in food processing and pest control: I. Wholesomeness of food treated with ionizing energy. Task Force Report No. 109. Council for Agricultural Science and Technology, Ames, Iowa.

• CAST. 1989. Ionizing energy in food processing and pest control: II. Applications. Task Force Report No. 115. Council for Agricultural Science and Technology, Ames, Iowa.

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