OUM-NESTLE 2008 3

Executive Diploma in Manufacturing Management

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LECTURE NOTES 03/08“IRRADIATION PROCESS”

SAIFUL IRWAN ZUBAIRI PMIFT, Grad B.E.M. B. Eng. (Chemical-Bioprocess) (Hons.), UTM

M. Eng. (Bioprocess), UTM

ROOM NO.: 2166, CHEMISTRY BUILDING,TEL. (OFF.): 03-89215828,

FOOD SCIENCE PROGRAMME,CENTRE OF CHEMICAL SCIENCES AND FOOD TECHNOLOGY,

UKM BANGI, SELANGOR

28 MAY 2008


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SUB-TOPIC: FOOD CONVERSION AND MANUFACTURING Cooling and Freezing process.

Concentration & Dehydration: Concentration, Spray Drying & Vacuum Drying process.Industrial Fermentation process. Irradiation Process.Homogenization Process.Wet and Dry Mixing process.Transport and Conveying process.


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Radiation: Form of energy

What is the Radiation?RADIATION: “The emission of energy

through space or material in the form of waves”.

Electromagnetic radiation? Waves or rays in the electromagnetic

spectrum.


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Electromagnetic Spectrum


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What is irradiation?

Application of high energy to products, including food.

The reason we used irradiation: To sterilize or pasteurize by killing harmful insects, bacteria, parasites and mold.

Preservation method that uses short waves of the electromagnetic spectrum.


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What non-food products are irradiated?

Personal hygiene products

ToothbrushesBandagesFlossSurgical packs

Toilet paperQ tipsFeminine productsCosmeticsSome tiresMany more

“These undergo radiation treatment in Co-60 (Cobalt-60) facilities throughout the United States”


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Sources of ionizing radiation

1. Gamma raysCo-60: The most common radioisotope

used (Food Technologies Inc, & Mulberry)It has the deepest penetration. Used to sterilize many non-food items.Can be applied to various foods, sizes,

shapesRaises consumer concerns = Radioactive

residual in the items.


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2. X-raysMachine that produced the x-rays are powered by

electricity.A lot of consumers in the world are familiar with

the technology. Widely used in the health care treatment.But unfortunately, it is not yet widely adopted for

food application.



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3. Electron beam: () beta rays Machine that produced electrons which is

powered by electricity.It is a short penetration and it requires a thinner

product in order the rays being penetrated.Works well with meat pieCompany that used this source: Titan facility-

Iowa, USA.



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How does radiation work?

1. Direct Effects: Kills microorganisms by damaging bio molecules in cellsPhotons of radiation hit electrons in atoms of microbes or

food molecules. It transfers energy to the electrons. Electrons scatter and collide with other electrons. Chemical bonds are broken, disrupting cell metabolism and

other cells division (DNA and RNA and cellular proteins)


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2. Indirect Effects: Water molecules in organisms or food undergo radiolysis (disruption through radiation).

It will form a “free radicals”: atoms or molecules having an unpaired electron.

Then, it quickly combines with oxygen to form oxidizing agents that damage bacterial cells and eventually leading to death of organism.

“The combined effects (indirect & direct) can result in the destruction of target organisms

efficiently”

How does radiation work?


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Measure of radiation dose

Unit is the “gray” (Gy)

FDA uses kilogray (kGy) = 1,000 grays


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(1) Low dose: 0 - 1 kGyDisinfest grains of insects Inhibit the developing of microbes. Control Trichinella spiralis in the pork meat. Delay ripening in fruits and vegetables.


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(2) Medium dose: 1-10 kGy

Reduce the availability of the microbial pathogens in the meat, poultry and fish

Reduce spoilage of microorganisms.Delay the mold growth on strawberries and

other fruits


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(3) High dose: 10 - 50 kGy

Kill microorganisms in spices and herbs preparation ingredients.

Commercially to sterilize the food. Disadvantage: It can cause the functional

ingredient in food to modify.


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RULE OF THUMBS: Complex organisms require LESS radiation

to affect or destroy them. Simple organisms like bacteria take higher

doses to be destroyed than insects.


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Effects on food products?

Foods do not become radioactive after being exposed to the irradiation process.

But some chemical changes may occurred.e.g: Unique radiolytic product can be formed: 2-

dodecylcyclobutanone (2-DBC)No toxic effects, not mutagenic. Food also changes when it is cooked = so,

expect the same effect the irradiated food products.


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Irradiated of “Cold product”There is a small effect for certain nutritional compounds

if any of the chilled food product increases in temperature during the irradiation process.

But no changes in physical appearances occurred.e.g: At 1.5 kGy or 3.0 kGy for the ground meat. There

are:

- No adverse effects on thiamin or riboflavin (crucial amino acid contents).

- No negative effects on meat color.


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Grilled food Frozen food


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Regulated by the U.S. Food & Drug Administration (FDA)

The irradiated food has be used as a food additive since 1958 under the Federal Food, Drug and Cosmetic Act of 1938.

Various irradiated product has been approved by the FDA since 1963.


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Product Date Purpose

Wheat/flour 1963 Insect disinfest

Potatoes 1964 Sprout inhibition

Pork 1985 T. spiralis control

Fruit 1986 Microbial control

Vegetables 1986 Ripening control

Insect disinfest

Seasonings 1986 Microbial control

Poultry 1990 Microbial control

Meat - FDA 1997 Microbial control

Meat - USDA 1999 Microbial control

Eggs 2000 Microbial control

Irradiation Approvals


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Past decadeIn 1993, food borne illness from E. coli O157:H7

has infected USA - Hundreds were ill, several were deaths.

Source of the infection: associated with the ground beef.

Because of the E. Coli were widely spreaded, US government has approved for the irradiation of meats to inhibit E. coli.

The effect: It was a great reduce of the pathogens in the ground beef. But it does not sterilize the product from other microbes.


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Regulation on Meat by the FDA 1997 & USDA 1999

For the uncooked meat and its by product:- Refrigerated meat: the radiation can be used up to 4.5 kGy- Frozen meat: up to 7.0 kGy

The HACCP system should be implemented along with the irradiation process.

Labeling of consumer foods should be imprinted:-e.g: “Treated by electron beam irradiation”-e.g: “Treated to reduce pathogens such as Salmonella”-e.g: “Irradiated ground beef”.


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What Is Food Irradiation?

“Food irradiation is the process of exposing food, either packaged or in bulk to carefully

controlled amounts of ionizing radiation for a specific time to achieve certain desirable

objectives”


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Ionizing RadiationIonizing Radiation: “X-rays, alpha, beta, and gamma rays (short wavelength-high energy) which cause whatever material they strike to

produce ions”


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BENEFITS OF FOOD IRRADIATION LOW DOSE (up to 1 kGY)

(FDA approved for grain, fruits, vegetables, and pork)

Inhibits growth of sprouts on potatoes, onions, and garlic.Slows ripening process, keeping fruits and vegetables from

spoiling by a few days (e.g.: mushrooms) to a few weeks (strawberries).

Kills insects found in wheat, flour, fruits, and vegetables.Eliminates parasites such as trichinosis-causing the

appearance of parasites colony in pork.


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Extends shelf-life of fresh fish, strawberries, etc.Reduces or eliminates spoilage and pathogenic

microorganisms and parasites like salmonella.Inhibits mold on fruits.

BENEFITS OF FOOD IRRADIATION MEDIUM DOSE (1-10 kGY) (FDA approved for poultry)


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Sterilizes food for hospital diets of those with immune system disorders.

BENEFITS OF FOOD IRRADIATION HIGH DOSE (10-50 kGY) (FDA approved for spices)


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Safety Issues for the ConsumerRadioactivity?Chemical changes?Nutritional qualities?Microbiological mutations?Genetic changes?Effect on food additives?Packaging?


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Need for Detection Method

The International Food Trade Organization (IFT) is developed to assure that all manufacturer that used irradiation method has to compliance with regulations

Protect freedom of information and choices for the consumers.

Protection from fraud informationMake enforcement of labeling that uses the radiation

so that consumers will fell confidence with the food products.


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Types of Detection Methods

ChemicalBiologicalPhysical


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Status of Physical Methods


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Applications (Physical Methods)

(1) Impedance

-Potatoes

(2) Viscosity-Pepper

(3) Chemiluminescence

-Spices, herbs

-Dry vegetables

(4) Thermoluminescence -Spices, herbs (minerals) -Fruits, veggies (minerals) -Shellfish

(5) EPR -Meat, poultry, fish -Nuts, dry fruits/veggies -Fresh fruits -Shellfish -Whole eggs


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IS THERE A SIGNIFICANT DIFFERENCE ?

ANS: *Not much significant differences-The mean values is more less the same*


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IS IMPEDANCE RATIO A RELIABLE INDICATOR?


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Electron Paramagnetic Resonance (EPR)

EPR is a spectroscopic technique that detects chemical species that have unpaired electrons. A great number of materials contain such paramagnetic entities, which may occur either as electrons in unfilled conduction bands, electrons trapped in radiation damaged sites, or as free radicals, various transition ions, bi-radicals, triplet states, impurities in semi-conductors, as well as other types.


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Requirements of a Detection Method

Discrimination distinct and separable radiation-induced response

Specificity response not induced by other processing

Robustness

insensitive or predictable response

Reliability

Stability Confidence Practicability

rapid, simple, low cost & wide

applicability Dose-dependence

(quantification) ideal dose, not too much and not too small


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Food irradiation It involves subjecting the food to a close ionizing radiation

(gamma-rays). Effective & safe method of extending shelf life of food. It destroy parasites, insects and microorganisms. DISADVANTAGES: Microbial spores & toxin unaffected. Food that commonly irradiated-spices, chicken, onions,

potatoes & strawberries. Doses used vary with the products.


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Irradiation

Spectrum of electromagnetic radiation(a) Short wavelengths (high energy) = ionizing radiation(b) Long wavelengths (low energy) = radio waves(c) Middle wavelengths = visible light

Microwaves Long wavelengths Heat food by making water molecules move very fast

Ultraviolet Shorter than visible wavelengths Can kill microbes Only used for surfaces

Ionizing radiation

Beta rays (electrons) Gamma rays (from radioactive source)


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Measuring radiation• Curie - Quantity of

radioactive substance

• Rad - Unit of measure for absorbed radiation dose

• Gray - New unit of measure (= 100 rads)

What does radiation do?

Damages DNA Causes chemical

changes in the cell


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Radiation vs. microorganisms

Different organisms vary in radiation resistance.

Some very resistant types exist.More cells present means more radiation

needed to be used to destroy their cell walls.Non growing cells are more resistant than

growing cells.


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How to choose the right dose?

Target size: Smaller the target, more radiation to be needed.

Desired effect: - Inhibit sprouting?

- Kill insects?

- Kill some bacteria?

- Kill all bacteria?

If possible take the lowest dose to do the desired job = less radiation during handling.


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Examples of irradiation processes

Control insects in fruits and vegetables up to 1 kilogray

Kill insects and microbes in spices up to 30 kilogray

Control Trichinella (a parasite) in pork 0.3-1 kilogray

Inhibit sprouting of potatoes 50-150 gray

Control insects in wheat and flour 200-500 gray

OUM-NESTLE 2008 3

Technology

Transcript of OUM-NESTLE 2008 3