Irradiation contribution in improving the microbial quality of food.

1. UNIVERSITY OF PORTHARCOURT
FACULTY OF SCIENCE
MICROBIOLOGY DEPARTMENT.
A
SEMINAR PRESENTATION
ON:
IRRADIATION CONTRIBUTION IN IMPROVING THE MICROBIAL QUALITY OF FOOD.
BY
ERHUVWU UKOCHOVWERA AND AGGREH ERHOVWON PETER
U2010/4725069 AND U2011/5555010
MCB 409.2
SUPERVISOR: MRS NNENA OMORODION
OCTOBER, 2015.

2. OUTLINE
 INTRODUCTION
 LITERATURE REVIEW
 STATEMENT OF PROBLEMS
 RESEARCH FOCUS
 THE ACTUAL PROCESS OF IRRADIATION
 WHY THE INTEREST IN IMPROVING THE MICROBIAL QUALITY OF FOOD?
 THE CONTRIBUTIONS OF IRRADIATION IN IMPROVING THE MICROBIAL QUALITY OF FOOD.
 WOULD IRRADIATION REPLACE OTHER FOODBORNE DESEASE PREVENTION EFFORTS?
 CHALLENGES OF FOOD IRRADIATION.
 CONCLUSION
 REFERENCES

3. INTRODUCTION
Food irradiation is a new food safety technology that can eliminate disease
causing germs such as E. coli O157:H7, Campylobacter and Salmonella from
foods.
Shelf life is the length of time that a commodity (food) may be stored without
becoming unfit for use, consumption or sale.
Food borne disease (also foodborne illness and colloquially referred to as food
poisoning is any illness resulting from the food spoilage of contaminated food,
pathogenic bacteria, viruses, or parasites that contaminate food.

4. LITERATURE REVIEW
TABLE 1. A LIST OF SOME OF THE ARTICLES USED IN THIS SEMINAR PRESENTATION.
S/N TITLE OF
PUBLICATION
YEAR OF
PUBLICATION
AUTHOR(S)
1 Effect of gamma
irradiation on the
microbial quality of
dried fishes
2014 Sinduja et al
2 Irradiation and
Food Safety
2004 Scoth et al
3 Scientific Opinion
on the efficacy and
microbiological
safety of irradiation
of food
2011 European Food
Safety Authority
(EFSA), Parma, Italy

5. STATEMENT OF PROBLEMS
Prevalence in foodborne diseases due to poor safety sanitary
techniques.
High rate of food loss as a result of contamination and
spoilage.
Absence of safe food for immune deficient patients.

6. RESEARCH FOCUS
TO EVALUATE THE COMPETENCE OF IRRADIATION IN IMPROVING THE MICROBIAL QUALITY OF
FOOD.

7. HISTORY
 Food irradiation started in the 20th century.
 In 1905, J Appleby and A. J Banks brought about an improvement in the
conditions of food stuffs.
 In 1921, B. Schwartz (US) published use of X rays for inactivating Trichinae sp in
raw pork.
 In 1930, O. West: French patent: killed bacteria in packaged food with X rays.
 Other years of development includes: 1957, 1966,1970-1984, 1979-1990.
 In 2004, International Consultative Group on Food Irradiation (ICGFI) was
established.
 2005 till presence has marked various development and improvement in food
irradiation.

8. THE ACTUAL PROCESS OF IRRADIATION?
Three different irradiation technologies exist.
The use of gamma rays, electron beams and x rays.
Fig 1. An electron beam irradiator for food poisoning
Source. Google downloads.

9. WAYS TO MEASURE THE AMOUNT OF
IRRADIATION
 The doses of irradiation is usually measured in unit called the Gray, abbreviated Gy.
 The Gray is the measure of energy transferred to food, microbe or other substance being
irradiated.
 Applications up to 1KGy, between 1& 10KGy and higher than 10KGy are referred to as low
dose, medium dose and high dose respectively.

10. WHY THE INTEREST IN IMPROVING THE MICROBIAL
QUALITY OF FOOD BY IRADIATION?
 Increase concerns over food borne diseases.
 High food loses from infestation, contamination and spoilage.
 Growing international trade in food production
 Increase in human population.
 Increase in immune deficient patients.

11. THE CONTRIBUTIONS OF IRRADIATION IN IMPROVING
THE QUALITY OF FOOD
Reduction of pathogenic microorganism.
Extension of food shelf life.
Inhibition of sprouting.
It proactively prevents insects from affecting.
People with immune deficiency are of highly advantage.

12. SOME TARGET ORGANISMS IN FOOD
IRRADIATION.
 Staphyloccus aureus
 Campylobacter jejeni
 Salmonella heidelberg
 Salmonella enteriditis
 Listeria monocytogenes
 Escherichia coli O157:H7

13. CAN IRADIATION BE USED TO MAKE SPOILED
FOOD GOOD?
 No
 Neither irradiation nor any other food treatment can reverse the spoilage process and make
bad food good.
 Irradiation can reduce or eliminate spoilage bacteria or pathogenic microorganisms but
cannot improve the sensory quality.

14. FACTS APPROVED FOR IRRADIATION IN THE
UNITED STATE.

15. MECHANISM OF FOOD IRRADIATION- A MICROBIOLOGICAL
PERSPECTIVE
 When microbes present in the food are irradiated, the energy from the rays is transferred to
the water and other molecules in the microbe.
 The energy creates transient reactive chemicals that damage the DNA in the microbe.
 This cause defects in the genetic instruction of the microbe
 Microbes find it difficult to repair after been irradiated and they die during duplication.
Fig 2. A schematic representation of effect of irradiation on food.

16. Fig 2. An isotope source facility used in food irradiation.
Source: S.K Saravana.

17. WOULD IRRADIATION REPLACE OTHER
FOODBORNE DISEASE PREVENTION EFFORTS?
 No
 Irradiation is not a shortcut that means food hygiene efforts can be relaxed.
 Many steps need to be taken from farm to table (GMP) to make sure our food supply is clean
and safe.
 Lastly for irradiation to be very effective, the food of interest also need to be clean.

18. CHALLENGES OF FOOD IRRADIATION
 Food may be susceptible to chemical changes which may affect taste, odour and safety.
 There is no guarantee that it can kill everything in the food.
 Some research conducted shows that some animals have reacted negatively to irradiated
foods.

19. LABELLING OF IRRADIATED FOOD
 The presence of the international symbol of irradiation known as radura in the food.
 The presence of a statement indicating that the food was treated with irradiation.
Fig 3. The international symbol of food irradiation (radura).
Source: Google downloads

20. DOES THE IRRADIATION PROCESS MAKES
FOOD RADIOACTIVE?
 No
 Only trace amounts of radioactive elements is used in food irradiation
 Everything in our environment including food contains trace amounts of radioactivity.
 The food itself never come in contact with the radioactive source.

21. ORGANIZATION THAT MONITORS THE SAFETY OF IRRADIATED
FOOD .
 WHO- WORLD HEALTH ORGANIZATION
 USDA- UNITED STATE DEVELOPMENT AGENCY
 NRC- NUCLEAR REGULATORY COMMISSION
 NAFDAC
 FAO- FOOD AND AGRICULTURAL ORGANIZATION
 FDA- FOOD AND DRUG AGENCY
 MINISTRY OF HEALTH
 IAEA- INTERNATIONAL ATOMIC ENERGY AGENCY

22. CONCLUSION/ RECOMMENDATION
 Irradiation has contributed earnestly to the improvement of food quality.
 Irradiation should be considered as one of the several approaches in reducing food pathogen.
 Irradiation should be used in conjunction with integrated food safety management program
and bodies.
 There be reduction of dose when irradiating food.
 There should be public sensitization programs about the safety of this new promising
technology.

23. THANK YOU FOR YOUR TIME.

24. REFERENCES
European Food Safety Authority (EFSA), Parma, Italy. (2011). Scientific opinion on the efficacy.
and microbiological safety of irradiation of food. European food safety authority. 9(4): 1-10.
Sinduja, P., Immaculate, J., Edward, P.J.K and Patterson, J. (2014). Effect of gamma irradiation on
the microbial quality of dried fishes. The Australian Journal of applied microbiology. 1(3):
26-48.
Smith, J. S and Pillai, S. (2004). Irradiation and food safety. Scientific status summary. 58: 48-55.