Applications of Nuclear Techniques in Food Preservation by using gamma radiation.

1. Quality and elemental characterization of common spices
of Bangladesh using nuclear reactor-based NAA and
gamma irradiation techniques
Md. Mahfuzur Rahman
M.Sc. in Nuclear Science & Engineering
1

2. Outlines of the study
2
Introduction
Literature Review
Objectives
Neutron Activation Analysis (NAA)
Gamma Irradiation Technique
 Experimental Setup
Results and Discussion
Summary

3. Introduction
Application of nuclear techniques is an important issue for
energy production as well as for food and environmental safety.
Spices are widely used as additional components to improve
flavor, color and taste of foods items since ancient times.
 Spices are Contaminated by:
-Heavy Metals: Cr, Cd, As, Pb, Co, Ni etc.
-Foodborne bacteria: Bacillus, Salmonella, E.coli, Listeria,
Pseudomonus spp.
-Fungus- Aspergillus, penicillium and Mucor.
 Probable Diseases: Cancer, heart disease, kidney disease
lungs, liver and diarrhea etc.
3

4. Introduction (Cont.)
Essential elements of Spices: K, Zn, Fe and Ca etc.
Neutron activation analysis (NAA): NAA is the
nuclear process used for determining the concentrations
of elements in a vast amount of materials. This
technique also applies to analyze in environmental,
biological and archeological samples.
Gamma radiation (GR): GR is a form of
electromagnetic radiation, which is the radiant energy
released by certain electromagnetic process and
expressed in waves.
4

5. Literature Review
Previous Research Works
1. Rahman, M., and Islam, M. A. (2019). Concentrations and health risk
assessment of trace elements in cereals, fruits and vegetables of
Bangladesh. Biological Trace Element Research, 191(1), 243-253.
2. Shaheen, N., Irfan, N. M., Khan, I. N., Islam and Ahmed, M. K.
(2016). Presence of heavy metals in fruits and vegetables: Health risk
implications in Bangladesh. Chemosphere, 152, 431-438.
3. Alam, M. K., Choudhury, N., Chowdhury, N. A., and Youssouf, Q. M.
(1992). Decontamination of spices by gamma radiation. Letters in
Applied Microbiology, 14(5), 199-202.
Observations from previous works
Limited number of samples were characterized.
Limited number of organisms identified from limited samples.
5

6. Objectives
 To characterize essential and toxic elements in
common spices of Bangladesh using research reactor
based NAA and AAS techniques.
To assess physicochemical and pathogenic organisms
change in the studied spices due to different doses of
gamma irradiation.
 To assess different hazard indicates as well as to
compare elemental data of the studied spices with
different international recommended values.
6

7. Neutron Activation Analysis
Fig: Illustration process of NAA
What is NAA?
Neutron activation analysis (NAA) is a highly sensitive method
for the accurate determination of elemental concentrations in a
material.
7

8. Equation for relative NAA
Where,
A= Activity of the radionuclide
N= Number of radionuclide
𝛔= Effective cross section for (n,ɤ) reaction
Ф= Neutron flux M= Mass of the element
𝝀 =Decay constant
𝒕𝒅= Decay time
𝒕𝒄 =Counting time
𝒕𝒊 = irradiation time W= Mass of the irradiated target element
Irradiation factor, 𝑭𝒊 = 𝟏 − 𝒆−𝝀𝒕𝒊
Decay factor, 𝑭𝒅 = 𝒆−𝝀𝒕𝒅
Counting factor, 𝑭𝒄=
𝟏−𝒆−𝝀𝒕𝒄
𝝀𝒕𝒄
Basic equation of NAA
W=
𝑨𝑴
𝑵θ 𝛔Ф𝑭𝒊 𝑭𝒅 𝑭𝒄
𝜣= Isotopic abundance of target element 8

9. Experimental Setup
Sample collection
There are total 25 no. of spice powder samples were collected from
local market of Dhaka, Bangladesh.
Samples list
9
Sl no Name of samples
1 Red chili
2 Turmeric
3 Garlic
4 Ginger
5 Black pepper
6 Coriander
7 Cumin
8 Green chili

10. Experimental Setup
Sample preparation for NAA
Sample
collection
Drying Properly mixing packing
Standards
Peach Leaves (NIST-1547), Apple leaves (NIST 1515) and Lichen
(IAEA-336).
Fig: Steps of spices irradiation process
Vial Rabbit
system
Sample carrier HPGe Detector Monitor
Sample irradiation Steps
10

11. Experimental Setup
Experimental conditions
TRIGA Mark II Research
Reactor at AERE
11
Short Long
Irradiation time 1 min 7 min
Reactor Power 250 KW 2.4 MW
Counting time 5 & 10 m 30 m & 2 h
Thermal neutron
flux
1012 n/cm2/s 1013 n/cm2/s

12. Experimental Setup
Radionuclides with their half-lives and gamma-ray energies
Elements Product
radionuclide
Half-life Gamma-ray energy
(KeV)
Al 28Al 2.24 m 1779
V 52V 3.74 m 1434.1
Ca 49Ca 8.72 m 3084.4
Cl 38Cl 37.3 m 1642.4
K 42K 12.4 h 1524.6
Mn 56Mn 2.58 h 1810.7
Na 24Na 14.7 h 1368.6
12
For short irradiation

13. Experimental Setup
Elements Product
radionuclide
Half-life Gamma-ray energy
(KeV)
Co 60Co 5.27 y 1173.2, 1332.5
Cr 51Cr 27.7 d 320.1
Fe 59Fe 44.5 d 1099.2, 1291.6
Sc 46Sc 83.8 d 889.3, 1120.5
Br 82Br 35.3 h 554.3
Zn 65Zn 244 d 1115.5
13
For long irradiation

14. Quality control
Comparison of measured values with their certified values in
Peach leaves and Apple leaves
0.7
0.8
0.9
1
1.1
1.2
1.3
As Ca Cl Cr K Na Pb V
Concentration
ratio
Elements
Al Br Cd Co Fe Mn Ni Sc Zn
SRM-1547 (peach leaves)
0.7
0.8
0.9
1
1.1
1.2
1.3
As Ca Cl K Na Pb Zn
Concentration
ratio
Elements
SRM-1515 (apple leaves)
Al Br Cd Fe Mn Ni V
14

15. Results and Discussion
Element abundances (mg/kg) in the spices
15
 Concentrations of 17 elementals were determined.
As, Pb, Ni and Cd concentrations were determined
by AAS and rest of the elemental concentrations
were determined by NAA.
Pb and Cd concentrations were higher than
WHO/FAO values.

16. Element abundances (mg/kg) in the spices
16
0
0.05
0.1
0.15
Red chili TurmericCoriander Cumin
Black pepperGarlic Ginger Green chili WHO
Conc.
(mg/kg)
As
Samples name
WHO Level (0.1)

17. Element abundances (mg/kg) in the spices
17
0
1
2
3
4
5
6
7
8
Red chili TurmericCoriander Cumin
Black pepperGarlic Ginger Green chili WHO
Cr
Concentration
(mg/kg)
Samples name
WHO Level (2.3)

18. Health Risk Assessment Formula
Estimated daily intake (EDI)
Target hazard quotient (THQ)
Target carcinogenic risk (TCR)
THQ=
𝑬𝑭𝒓×𝑬𝒅×𝑬𝑫𝑰
𝑹𝒇𝑫×𝑻
× 𝟏𝟎−𝟑
Where, 𝑬𝑭𝒓= Exposure frequency of elements (365day/year)
RfD= Oral reference dose (mg/kg/day)
T= Average time (365 day/year ×70 year)
𝑬𝒅=Exposure duration (70 years)
EDI= 𝑭𝑰𝑹 × 𝑪𝒆𝒍𝒆𝒎𝒆𝒏𝒕 /𝑩𝒘𝒆𝒊𝒈𝒉𝒕
Where, FIR= Daily food ingestion rate (g/person/day)
𝑪𝒆𝒍𝒆𝒎𝒆𝒏𝒕= Element concentration (mg/kg)
𝑩𝒘𝒆𝒊𝒈𝒉𝒕= Body weight (Consider 60 kg for adult)
TCR=
𝑬𝑭𝒓×𝑬𝒅×𝑬𝑫𝑰×𝑪𝑺𝑭𝑶
𝑻
×𝟏𝟎−𝟑
Where, CSFo= Oral cancer slope factor
(As=1.5, Pb=8.5×𝟏𝟎−𝟑 𝐦𝐠
𝐤𝐠
/𝐝𝐚𝐲)
18
Consumption rate were considered from BBS data

19. Comparison of Total Intake and MTDI Values (mg/day)
Spices As Cd Cr Mn Ni Pb Zn
Red chili 0.012 0.016 0.322 2.70 0.042 0.073 3.48
Turmeric 0.007 0.005 0.036 2.04 0.021 0.058 0.758
Coriander 0.004 0.004 0.127 0.908 0.016 0.018 3.86
Cumin 0.003 0.004 0.167 1.83 0.009 0.063 2.19
Black pepper 0.008 0.003 0.177 14.8 0.016 0.035 0.807
Garlic 0.005 0.003 0.467 1.93 0.015 0.030 1.73
Ginger 0.004 0.004 0.064 10.0 0.008 0.093 0.673
Green chili 0.015 0.009 1.39 2.37 0.029 0.056 5.37
Total intake 0.058 0.048 2.75 36.5 0.156 0.427 18.8
MTDI 0.126 0.046 0.2 2-5 0.3 0.21 60
MTDI= Maximum tolerable daily intake 19

20. Non-Carcinogenic Risk
Spices name As Cd Cr Mn Ni Pb Zn
Red chili 4.14E-2 5.19E-3 2.14E-4 1.92E-2 2.10E-3 2.10E-2 1.15E-2
Turmeric 2.36E-4 1.72E-3 2.45E-5 2.18E-2 1.07E-3 2.47E-3 3.78E-3
Coriander 1.28E-2 1.22E-3 1.09E-4 6.02E-3 7.75E-4 5.25E-3 1.19E-2
Cumin 1.16E-2 1.38E-3 1.11E-4 1.21E-2 4.75E-4 1.69E-2 6.76E-3
Black pepper 2.72E-2 1.16E-3 1.17E-4 9.81E-2 7.87E-4 9.28E-3 2.49E-3
Garlic 1.55E-2 9.72E-4 3.11E-4 1.28E-2 7.58E-4 7.89E-3 5.33E-3
Ginger 1.24E-2 1.36E-3 4.27E-5 6.63E-2 3.79E-4 2.49E-2 2.08E-3
Green chili 5.07E-2 2.91E-3 9.29E-4 1.69E-2 1.48E-3 1.60E-2 1.79E-2
Total 1.72E-1 1.59E-2 1.86E-3 2.53E-1 7.82E-3 1.04E-1 6.17E-2
 Non carcinogenic risk factor <1.0 indicates safe for health (Islam et al., 2019).
 Index values for the studied elements are less than 1, therefore the consumption of
this spices are safe. 20

21. Target Carcinogenic Risk
Ele Red
chili
Turmeric Coriander Cumin Black
pepper
Garlic Ginger Green
Chili
Total
As 6.25E-7 7.29E-7 1.57E-7 5.40E-7 2.98E-7 2.52E-7 7.99E-7 4.76E-7 3.88E-6
Pb 1.84E-8 1.05E-8 5.25E-9 5.25E-9 1.22E-8 7.00E-9 5.25E-9 2.10E-9 6.60E-8
If the value is greater than 10-4 : Unsafe (Iqbal et al., 2016)
 In this investigation, there were no carcinogenic risk to consume.
21

22. Gamma Irradiation Technique
 Gamma irradiation is mainly treated due to sterilization purpose.
 To eliminate the virus, bacteria, fungus and undesirable
organisms etc.
Spices were irradiated in the Institute of Food and Radiation
Biology, AERE, Savar, Dhaka.
 Applied doses range in the spices: 2-10 kGy
 Source: Cobalt-60 (Activity: 50 kCi)
Fig. Gamma source 22

23. Bacterial Load Reduction: Gamma Irradiation
Cfu/gm
23
 If gamma radiation dose increases, number of bacterial load decrease
Here, (Cfu=colony forming unit)

24. Fungal Load Reduction: Gamma Irradiation
Cfu/gm
24
 The graph represent that dose increases, number of fungal load decrease

25. Effects Irradiation on Physico-Chemical Properties
There are five properties: Moisture (%), Fat (%), Protein (%),
Ash (%) and pH were determined.
After 6
months
 The result showed that no significant changes before and after gamma
irradiation 25

26. Organisms Identification: Selective Media
26
Six selective media were used to identify the foodborne organisms
Name of selective media Organisms
Pseudomonas agar
Xylose lysine deoxycholate (XLD) agar
Listeria selective agar
Bacillus selective agar
Eosin methylene blue (EMB) agar
Thiosulfate citrate bile salts sucrose
(TCBS) agar
Pseudomonas spp.
Salmonella spp.
Listeria spp.
Bacillus spp.
E.Coli spp.
Vibrio spp.
 Pseudomonas, E. Coli and Vibrio spp. were not found in this study

27. Optimum Gamma Dose Identification
Spices Dose
(kGy)
Bacillus
spp.
Salmonella
spp.
Listeria
spp.
0 m 6 m 0 m 6 m 0 m 6 m
Red chili 0 +++ +++ +++ +++ +++ +++
2 +++ +++ +++ +++ +++ +++
4 +++ +++ --- --- +++ +++
6 --- --- --- --- --- ---
Turmeric 0 +++ +++ --- --- +++ +++
2 +++ +++ --- --- +++ +++
4 +++ +++ --- --- +++ +++
6 --- --- --- --- --- ---
Optimum dose: red chili & turmeric=6 kGy, Cumin, Coriander, Garlic and Black
pepper=4 kGy, Ginger=2kGy 27

28. Summary
Elemental analysis of common spices of Bangladesh was carried out.
Concentrations of 17 major and trace elements (Al, As, Br, Ca, Cd,
Cl, Co, Cr, Fe, K, Mn, Na, Ni, Pb, Sc, V and Zn) in spices were
determined.
The concentration of As, Cd, Cr and Pb in some spices were found
higher than WHO/FAO permissible levels.
Total dietary intake values for Cr, Mn and Pb were noticed higher
than the MTDI values.
However, estimated non carcinogenic and carcinogenic risk values
were within the safe limits.
Optimum dose for decontamination:
Red chili and Turmeric: 6 kGy
Cumin, Coriander, Garlic and Black Pepper: 4 kGy
Ginger: 2 kGy.
28

29. Recommendation for Future Works
29
 Molecular interactions due to exposure of
gamma ray will be analyzed by Fourier
transform infrared spectroscopy (FT-IR).
 Fungal mycotoxin contaminations will be done
by HPLC.

30. International Publications
30
(1) M. Rahman, M. A. Islam and Ruhul A. Khan (2018).
Characterization of Chemical Elements in Common Spices of
Bangladesh for Dietary Intake and Possible Health Risk
Assessment by INAA and AAS Techniques. Journal of
Radioanalytical and Nuclear Chemistry, vol. 318, pp. 1347-
1357. (Springer). Impact Factor: 1.186.
(2) M. Rahman, M. A. Islam, Ruhul A. Khan and M. Salimullah
(2019). Effect of Gamma Irradiation on Foodborne
Microorganisms and its Impact on Physico-Chemical and
Sensory Quality of Spices During Storage. Journal of
Radiation Physics and Chemistry. (Elsevier) Impact Factor:
1.984
(Submission date: 07-08-2019; Manuscript no: RPC_2019_363)

31. International Conferences
31
(1) M. Rahman, M.A. Islam, M. Z. I Mollah, A. Z. M. Salahuddin and
R. A. Khan (2018). “Effects of Gamma Radiation on Physico-
Chemical Properties and Elemental Characterization of
Common Spices of Bangladesh.” Presented (Oral) International
Conference on Physics-2018. Organized by Bangladesh Physical
Society, Dhaka University (DU). Date: 08-10 March, 2018.
(2) M. Rahman, M. A. Islam, M. S. Rahman, M. M. Zaved and R. A.
Khan (2017). “Assessment of Essential and Toxic Elements in
Common Spices of Bangladesh by Neutron Activation
Analysis.” Presented (Oral) at 2nd International Conference on
Physics for Sustainable Development and Technology 2017.
Organized by Department of Physics, Chittagong University of
Engineering and Technology (CUET). Date: 10-11 December,
2017.

32. References
32
1. Alam, M. K., Choudhury, N., Chowdhury, N. A., and Youssouf, Q. M. (1992).
Decontamination of spices by gamma radiation. Letters in Applied Microbiology, 14(5),
199-202.
2. Shaheen, N., Irfan, N. M., Khan, I. N., Islam, S., Islam, M. S., and Ahmed, M. K. (2016).
Presence of heavy metals in fruits and vegetables: Health risk implications in
Bangladesh. Chemosphere, 152, 431-438.
3. HIES (household income and expenditure survey) (2011) Preliminary report on
household income and expenditure survey-2010. Bangladesh Bureau of Statistics,
Statistics division, Ministry of planning, Dhaka.
4. FAO/WHO (2011) Joint FAO/WHO food standards program codex committee on
contaminants in foods, Food CF/5 INF/1. Fifth session. The Hague, The Netherlands.
5. Singh, V., and Garg, A. N. (2006). Availability of essential trace elements in Indian
cereals, vegetables and spices using INAA and the contribution of spices to daily dietary
intake. Food Chemistry, 94(1), 81-89.
6. Iqbal, H. H., Taseer, R., Anwar, S., Qadir, A., and Shahid, N. (2016). Human health risk
assessment: Heavy metal contamination of vegetables in Bahawalpur, Pakistan. Bulletin
of Environmental Studies, 1(1), 10-17.
7. Variyar, P. S. (1998). Effect of gamma‐irradiation on the phenolic acids of some Indian
spices. International Journal of Food Science and Technology, 33(6), 533-537.

33. Thanks a lot
33