The technology of food irradiation is popularly accepted and surely merit serious consideration by public health authorities, industry and consumer group worldwide. Its application potential is very diverse, from inhibition of sprouting of tubers and bulbs to production of commercially sterile food products. This technology can be utilized effectively as a novel postharvest technique to reduce postharvest losses,increase the quality of international trade of food and preserve the quality of food. These potentialities of technology currently driving the worldwide momentum towards commercial use of food irradiation.

1. UNIVERSITY OF HORTICULTURAL SCIENCES,
BAGALKOT
College of Horticulture , Bengaluru.
Name of the Student : SUJAYASREE.O.J
ID No. : UHS14PGM533.
Degree Programme and Subject : M.Sc., (Hort.) in Postharvest
Technology
College : College of Horticulture, Bengaluru.

4. INTRODUCTION
IRRADIATION TYPES &
SOURCES
HOW IRRADIATION WORKS?
APPLICATIONS
CASE STUDIES
CONCLUSION

5. • Process of treating food with a specific dosage of
ionizing radiation.
• The exposure of biological materials (food commodities)
to radiation, more particularly to mutagenic radiations.
• Irradiation is a deliberate treatment of a product by
exposing to gamma radiation from a radioactive source
or to a machine generated X-rays or electrons under
controlled conditions

6. “ First publication in 1895: On A New Kind Of Rays”

7. Antoine Henri Becquerel
(1852-1908)
He was a French physicist,
Nobel laureate, and the
discoverer of radioactivity in
1896 along with Marie
Skłodowska-Curie and
Pierre Curie, for which all
three won the 1903 Nobel
Prize in Physics. The SI unit
for radioactivity, the
Becquerel (Bq), is named
after him.

8. IRRADIATION TYPES
RADIATIONS
α particles
Β rays
γ rays
X raysUV-rays
cosmic rays
microwaves
Radiation --mode of heat transfer

9. TYPE OF
RADIATION
MODE OF
ACTION
NATURE SOURCE
α-particles Ionizing Particulate He2+
β-rays Ionizing Particulate K 40
γ-rays Ionizing Electromagnetic Atomic nucleus: Co60 and
Ce 137
X –rays Ionizing Electromagnetic Electrons: Tungsten (W),
Mo, Cu
UV-rays Non-ionizing Electromagnetic Sunlight, UV lamps, arc
welding, and mercury
vapour lamps
Microwaves Non-ionizing Electromagnetic low-frequency vacuum
tubes (Magnetron)
Mode of action, nature and source of radiations

10. IONIZING NON-IONIZING
Not enough energy to
remove electrons but
causes atoms to vibrate
e.g. sound waves,
visible light, UV and
microwaves.
Enough energy to remove
tightly bound electrons from
atoms, thus creating ions.
e.g. X-rays, gamma rays
For Irradiation: Ionizing radiations

11. 780 nm

12. • 60Co or 137Ce with respective energies
of 1.33 and 0.67 Mev
Gamma
rays
• Machine operated at a maximum
energy of 5 Mev
X rays
• Machine sources operated at a
maximum energy of 10 Mev
Electrons
IRRADIATION SOURCES

13. WHY GAMMA RAYS MOSTLY USED IN FOOD
IRRADIATION
Ionizing radiations penetrate the food to varying in degrees depending
on the nature of the food and the characteristics of radiations

14. Irradiation dosage depends on:
Nature of the food
Resistance of micro
organisms
Resistance enzymes
Cost of the process

15. World wide utilization of irradiation
Commercially allowed
Commercially not allowed

16. WHY IRRADITION?
Increasing concern over food borne diseases and
uses of certain chemicals in food.
High post-harvest food losses from infestation,
contamination, and microbial spoilage.
Stringent regulations related to quality and
quarantine in international trade in food products.

17. ADVANTAGES OF RADIATION PROCESSING :
High penetration and the cold nature of the processing
Physical and non-additive process
Minimal changes in food
Eco-friendly process
No harmful residue on material
Treatment can be applied to pre-packed commodities
No change in heat-labile aroma constituents of food

18. Disinfestation of insect pests in stored products
Disinfestation of quarantine pests in fresh produce
Delay ripening / senescence of fruits & vegetables
Inhibition sprouting in tubers, bulbs and rhizomes
Destruction of spoilage causing microbes in food
Eliminate food borne parasites and pathogens
MAJOR TECHNOLOGICAL BENEFITS

19. Irradiation: One process Multiple uses
Sprout inhibition Pathogen control
Insect
disinfestations
Shelf life
Quarantine

20. APPLICATIONS
• Radiation decontamination of medicinal plants and spices is
a safe and very effective method with negligible losses of the
biologically active substances (Andrzej and Wojciech ,2005).
• Gamma irradiation as an alternative treatment to abolish
allergenicity of lectins in food (Vaz et al.,2011).
• Carrot -3 kGy Gamma irradiation at 10◦C for 3 days higher in
the total phenolic contents (Song et al., 2006).
• Cucumber -3 kGy gamma irradiation all the bacterial
contents were reduced to below the limit of detection.(Lee et
al., 2006).

21. • Irradiation of fruits and vegetables imported into the US as a
phytosanitary crop protection measure against fruit flies and
mango seed weevil (APHIS, 2002).
• The use of gamma irradiationto generate cross-linked edible
coating or biodegradable packaging.(Lacroix .,et al 2000)
• Irradiation doses of up to 2.4kGy can be used with minimum
effect on the respiratory physiology of tissues in apple.(Gunes
et al.,2000)
• Irradiation as a Critical control point (CCP) in raw or
minimally processed products like meat,fish,seafood ,fruits
and vegetables.(Molins et al.,2000).

22. Radiation Dosimeter
Measuring doses
of radiations
Human protectionIndustrial processes

23. Schematic irradiation unit
Packaged food products
move along the conveyer belt
Food exposed to the rack
containing source pencils
Gamma rays pass through
the packaging and treat the
food
Absorbed dose -dosimeters at
various positions
Radiation source stored
under 6 m deep water when
not in use

24. Electron beam
Machine generates electron
and accelerated
A Conveyer moves the
product to be irradiated
under the electron beam to
obtain the desired dosage
X-Ray
Electron beam accelerator targets electrons on a metal plate
Energy is absorbed and the rest is converted to X-rays
X-rays can penetrate food boxes up to 15 inches thick

25. ➢ By disrupting the biological processes that lead to decay.
➢ In their interaction with water and other molecules that make up
food and living organisms, radiation energy is absorbed by the
molecules they contact.
➢ The reactions with the DNA cause the death of microorganisms
and insects and impair the ability of potato and onion to sprout.

26. LEVEL RANGE PURPOSE OF APPLICATION
Low dose
applications
Less than 1 kilo
Gray
1. Inhibition of sprouting in potato and
onion.
2. Insect disinfestation in stored grain,
pulses and products.
Medium
dose
applications
1 to 10 kilo Gray 1. Elimination of spoilage microbes in
fresh fruits, meat and poultry.
2. Elimination of food pathogens
3.Control of Microbes in spices and
herbs.
High dose
applications
Above 10 kilo
Gray
1. Sterilization of food
2. Shelf-stable foods without
refrigeration.
DIFFERENT DOSES OF FOOD IRRADIATION

27. NAME OF
PRODUCE
PURPOSE MINIMUM
DOSE ( kGy)
MAXIMUM
DOSE ( kGy)
Onion Sprout inhibition 0.03 0.09
Potato 0.06 0.15
Ginger 0.03 0.15
Garlic 0.03 0.15
mango Disinfection(
quarantine)
0.25 0.75
Spices Microbial
decontamination
6 14
Raisin, figs, dried
dates
Shelf life
extension and
pathogen control
2.5 4
Food items approved for radiation preservation under PFA
Rules, 1955:Rules, 1994, 1998.
Source: Lavale et al, 2000.

28. RADURA symbol for irradiated foods

29. IN INDIAN MARKET

30. Potato sprout inhibition and tuber quality after
postharvest treatment with gamma irradiation
on different dates
Rezaee et al., 2011
CASE STUDY 1

31. MATERIALS AND METHODS
• Design-split plot with 3 replication and 18
treatments.
• Sample size-3 kg
• Irradiation dosage-50 Gy(2 min. 18s),100 Gy(4
min .36s),150 Gy(6 mins.54s)
• Interval of treatment-10,30 and 50 days after
harvest.
• Irradiation source- Cobalt 60
• Storage after irradiation- half at 8oC and
remaining half at 16 0c at 85-90% RH for 5
months. Rezaee et al., 2011

32. Fig 1.Irradiation effects on percent weight loss of Agria potato tubers
irradiated in different dates and stored for five months at 8 and 16°C.
Rezaee et al., 2011

33. Fig 2:Irradiation effects on percent increase in specific gravity of Agria potato tubers
irradiated in different dates and stored for five months at 8 and 16°C.
Rezaee et al., 2011

34. Fig 3.Irradiation effects on percent loss of ascorbic acid of Agria
potato tubers irradiated in different dates and stored for five
months at 8 and 16°C
Rezaee et al., 2011

35. RESULT
• Study indicated that early irradiation and higher
irradiation levels significantly decreased sprouting,
percent weight loss and specific gravity of tubers.
• Tubers stored at 16°C showed greater metabolic
changes as indicated by sprouting, weight loss,
and changes in sugars and ascorbic acid contents.
• The 50 Gy irradiation treatment on the 10th day
after harvest resulted in complete sprout
inhibition of tubers at 8°C storage.

36. Retention of Quality and Nutritional
Value of 13 Fresh-Cut Vegetables Treated
with Low-Dose Radiation
Fan et al., 2008
CASE STUDY 2

37. MATERIALS AND METHODS
• 13 fresh cut vegetables-Lettuce,cilantro,parsley ,green
onion,carrot,brocolli,red cabbage,spinach,celery and tomato.
• Preperation of fresh cut vegetables and packaging done in
perforated zipper bags and tomato in polystyrene clampshell.
• Packaged in modified atmosphere and stored(4oC for 14 days).
• Irradiation source- Cesium 137 gamma irradiation source.
• Evaluation of appearance and aroma- using 9 point category scale.
• Headspace analysis- to determine the levels of CO2 and O2 after 1
and 14 days after irradiation using a fine hypodermic needle.
• Texture measurement and Vitamin C analysis.
Fan et al., 2008

38. Table 1:Aroma (9 to 1) of nonirradiated and irradiated fresh-cut
vegetables after 1- and 14-d storage at 4 ◦C.
Fan et al., 2008

39. Table 2:Appearance of nonirradiated and irradiated fresh-
cut vegetables after 1- and 14-d storage at 4 ◦C.
Fan et al., 2008

40. Table 3:Total vitamin C content (μg/g fresh weight) of nonirradiated and
irradiated fresh-cut vegetables after 1-and 14-d at 4 ◦C.
Fan et al., 2008

41. RESULTS
• The appearance of irradiated samples was similar to the
nonirradiated ones except that irradiated carrots, celery,
cilantro, and green onions had higher appearance scores
than corresponding nonirradiated vegetables.
• The aroma of several irradiated vegetables was significantly
better than controls after 14-d storage.
• The 1 kGy irradiation did not affect vitamin C content of
most vegetables.
• Most fresh-cut fruits and vegetables tested can tolerate up
to 1 kGy irradiation without significant losses in any of the
quality attributes.
Fan et al., 2008

42. Impact of low doses of gamma irradiation on shelf
life and chemical quality of strawberry
(Fragariaxananassa) CV. ‘Corona’
Majeed et al., 2014
CASE STUDY 3

43. MATERIALS AND METHODS
• Mature freshly harvested samples were collected
from Agriculture Research Institute,Tarnab
,Peshawar.
• Twenty fruits (500gm) packed in transparent
perforated plastic boxes.
• Irradiation doses-0.5,1,1.5 kGy.
• Radiation source-Cobalt 60 gamma radiation.
• Stored at 9 days at room temperature.
• Weight loss and quality analysis has been analysed.
Majeed et al., 2014

44. Fig 4:Gamma irradiation effect on shelf life of strawberry stored at
room temperature. Bars topped by different alphabets differ
significantly at p≤0.05 as revealed by LSD Majeed et al., 2014
5.75 days
7.75 days

45. Fig 5:Effect of different doses of gamma irradiation on weight
loss of strawberry at different storage period.
Bars of the same color topped by similar letter are not
significantly different (p≤0.05) Majeed et al., 2014

46. Fig 6:Effect of gamma irradiation on decay of strawberry at
different storage period. Bars of the same color topped by similar
letter do not differ significantly (p≤0.05). Majeed et al., 2014

47. RESULTS
• Irradiated fruit samples had lesser decay and
weight loss.
• Radiation doses 1.0 and 1.5 kGy might be used
as consumers’ acceptable doses for shelf life
extension,minimum weight loss and decay,
without affecting the chemical quality of
strawberry.
Majeed et al., 2014

48. Effect of gamma radiation on the inactivation of
Aflatoxin B1 in food and feed crops
CASE STUDY 4
Ghanem et al., 2008

49. MATERIALS AND METHODS
• Inoculation with the fungus
• Irradiation with gamma ray-4, 6, and 10 kGy
• Irradiation source-Cobalt 60.
• Aflatoxin extraction and clean up
• Aflatoxin quantification
Ghanem et al., 2008

50. Table 4:Effect of gamma radiation on aflatoxin degradation
in feed products.
Radiation Dose
(kGy)
Aflatoxin concentration (mg kg-1) ± S. D. (% degradation)
Barley Barn Corn
0 6.41±0.61 6.67±0.7 9.62±0.5
4 3.52±0.29(45.04%) 3.53±1.05(52.94%) 6.63±1.24(31.21%)
6 2.15±0.14(66.19%) 1.63±0.68(75.54%) 2.68±1.00(72.11%)
10 6.65±0.10(89.86%) 0.9±0.1(86%) 1.52±0.2(84.23%)
Numbers within each column followed by different small letters are
significantly different (p<0.01).
Ghanem et al., 2008

51. Fig 7:Correlation between oil content in food oil- crops and aflatoxin B1
degradation
Ghanem et al., 2008

52. RESULTS
• Degradation of AFB1 was positively correlated
with the increase in the applied dose of
gamma ray for each tested sample.
• At a dose of 10 kGy percentages of AFB1
degradation reached highest values.
• AFB1 degradation in food samples correlated
negatively with oil content in irradiated
samples
Ghanem et al., 2008

53. Effectiveness of Radiation Processing in
Elimination of Salmonella Typhimurium and
Listeria monocytogenes from Sprouts.
CASE STUDY 5
Saroj et al., 2006

54. MATERIALS AND METHODS
• Bacterial strain: Salmonella Typhimurium MTCC 98 &
L. monocytogenes NCAIM-B-01442.
• Seed and sprout samples inoculated with Salmonella
Typhimurium were exposed to a radiation dose of 0.1,
0.2, 0.3, 0.4, 0.5, and 0.6 kGy.
• Seed samples inoculated with L. monocytogenes were
exposed to a radiation dose of 0.25, 0.5, 0.75 and 1 kGy
and sprout samples with a dose of 0.5, 1, 1.5 and 2 kGy.
• Samples are aseptically homogenized ,plated and CFU
values are determined.
• D10 values were determined.
Saroj et al., 2006

55. Fig:8-Radiation sensitivity of Salmonella Typhimurium in sprouts.
Each symbol represents plate counts at each dose. Average values
of three experiments are plotted along with standard deviation.
Saroj et al., 2006

56. Fig 9:Radiation sensitivity of L. monocytogenes in sprouts .
Each symbol represents plate counts at each dose.
Average values of three experiments are plotted along with standard deviation.
Saroj et al., 2006

57. Table 5:Effect of irradiation on the growth of Salmonella Typhimurium
and L. monocytogenes inoculated in mung sprout samples

58. RESULTS
• Radiation treatment with a 2-kGy dose resulted in
complete elimination of 104 CFU/g of Salmonella
Typhimurium and 103 CFU/g of L. monocytogenes from
all the four varieties of sprouts.
• Radiation treatment with 1 kGy and 2 kGy resulted in a
reduction of aerobic plate counts and coliform counts by
2 and 4 log CFU/g, respectively.
Saroj et al., 2006

59. KRUSHAK
• This facility is located at Lasalgaon, in Nashik
District.
• KRUSHAK - ‘Krushi Utpadan Sanrakshan
Kendra’, literally translated in English as
‘agricultural produce conservation centre’.
• This irradiator is a specially designed technology
demonstration unit for low dose applications of
irradiation, primarily for controlling sprouting in
stored onions and insect disinfestation of agricultural
commodities for storage and quarantine.
• This is a successful example of transfer of irradiation
technology in this country.

60. o Hindustan Agro Co-operative Ltd., Rahuri, Ahmednagar
o Agrosurg Irradiators Pvt. Ltd., Mumbai
o Innova Agri Biopark Ltd., Bengaluru
o Microtrol Sterilization Services Pvt Ltd., Bengaluru
o Jhunsons Chemicals Pvt. Ltd., Bhiwadi, Rajasthan

61. 1)Bhabha Atomic Research Center, Bombay
2) Analytical Quality Control Laboratory, CFTRI, Mysore
3) Central Food Laboratory, Calcutta
4) Central Food Laboratory, Pune
5) University dept. of Chemical technology, Bombay
6) Food Research and Standardization Laboratory, Gaziabad

62. • 2001 -Board of Radiation and Isotope Technology
Department of Atomic Energy BRIT/BARC Vashi -a
radiation processing plant at Vashi, Navi Mumbai, was
built in order to process spices(for high dose applications
like microbial decontamination of spices and dry
ingredients)
o 2002-Low dose applications like sprout control in onion
and potato, disinfestations of cereals and quarantine
treatment at Lasalgaon, near Nasik in Maharashtra
commissioned

63. CONCLUSION
• The technology of food irradiation is popularly accepted
and surely merit serious consideration by public health
authorities, industry and consumer group worldwide.
• Its application potential is very diverse, from inhibition
of sprouting of tubers and bulbs to production of
commercially sterile food products.
• This technology can be utilized effectively as a novel
postharvest technique to reduce postharvest
losses,increase the quality of international trade of food
and preserve the quality of food.
• These potentialities of technology currently driving the
worldwide momentum towards commercial use of food
irradiation.

64. FUTURE THRUST
Still not widely used because of misconception of
consumers on its products
Improving consumer acceptance
Reducing processing costs
Combining beneficial effects of irradiation and other
ingredients to improve sensory characteristics.