ELECTRON SPIN RESSONANCE IDENTIFICATION OF IRRADIATED FOOD
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Transcript of ELECTRON SPIN RESSONANCE IDENTIFICATION OF IRRADIATED FOOD
ELECTRON SPIN RESSONANCE ELECTRON SPIN RESSONANCE IDENTIFICATION OF IRRADIATED FOODIDENTIFICATION OF IRRADIATED FOOD
LIN/COPPE/UFRJ
Prof. Edgar Francisco Oliveira de JesusProf. Edgar Francisco Oliveira de Jesus**
Prof. Ricardo Tadeu LopesProf. Ricardo Tadeu Lopes**
Dr. Alexandre Malta RossiDr. Alexandre Malta Rossi****
*Laboratório de Instrumentação Nuclear (Escola de Engenharia/COPPE/UFRJ)
**Centro Brasileiro de Pesquisas Físicas (CBPF)
LIN/COPPE/UFRJ
Standard Method Products EN 1784 GC of hydrocarbons Chicken, Pork, Beef,
Avocados, Mangoes, Papayas,Camembert
EN 1785 GC/MS of 2-alkylcyclobutanones Chicken, Pork, Liquid wholeegg
EN 1786 ESR spectrocopy of bones Chiken, Fish, Frog legs EN 1787 ESR spectrocopy of celulose Paprika powder, Pistacho nut
shells, Strawberries EN1788 Thermoluninescence of silicate Herbs and Spices, Shrimps, pr EN 13708 ESR spectrocopy of sugars Dried Papayas, dreied
mangoes, dried figs Raisins pr EN 13751 Photostimulated luminescence Herbs and Spices, Shellfish pr EN 13783 Microbiological screening Herbs and Spices pr EN 13784 DNA comet assay Chiken, Pork, Plant cells,
seeds.
H. Delincée - “Analytical methods to identify irradiated food¯¯a review” Radiation Physics Chemistry; 63, 3-6; p.455-458, 2002
Electron Spin Resonance (ESR)Electron Spin Resonance (ESR)
LIN/COPPE/UFRJ
Radiation SourcesRadiation Sources
LIN/COPPE/UFRJ
“Brokhawen Portable Cesium Development Irradiator” (BPCDI) - IPE, CETEX., Guaratiba, RJ.Césio-137 with 3,99 x 1015 Bq (108.000 Ci), in 1969Actual dose rate - 30.0 Gy/min
Gammacell 220 Excel - Nordion - Laboratório de Instrumentação Nuclear COPPE/UFRJCobalto-60 with 3.08 x 106 Bq (12,000 Ci), in 2000Actual dose rate - 90 Gy/min
LIN/COPPE/UFRJ
IPD Irradiator - Frontal view.
LIN/COPPE/UFRJ
Gammacell Irradiator
ESR MeasurementsESR Measurements
LIN/COPPE/UFRJ
Bruker ESP300E spectrometer (CBPF)
Bruker EMS104 spectrometer (LIN)
Alcoholic Extraction TreatmentAlcoholic Extraction Treatment
LIN/COPPE/UFRJ
Compact the pulp without seeds and skin, in a uniform sample; About six grams of the pulp is treated with 40 ml 80% ethyl alcohol solution in de-ionized water; The insoluble solid fraction is then separated by filtration; Remove the excess of water and left to dry at ambient temperature for one hour; 100 mg of the dry matter is then pressed in an acrylic matrix by a steel stick; The resulting sample, consisting of a cylinder 2.5 mm in diameter and 15 mm high, is measured by ESR in a quartz tube.
Products Products
LIN/COPPE/UFRJ
Papaya Tomato Kiwi Apple Pineapple Strawberry Pear Mango
Pumpkin Carrot Potatoes
Onions Garlic
ESR SpectraESR Spectra
LIN/COPPE/UFRJ
342 344 346 348 350 352 354
g = 2.0030
g = 2.0201
g = 2.1985
3.05 mT
1.0 mT
0.6 mT
0.6 mT
Magnetic Field (mT)
342 344 346 348 350 352 354
g = 2.0045
Tomato
Papaya
kiwi
Magnetic Field (mT)
Non-irradiated SamplesIrradiated Samples
LIN/COPPE/UFRJ
ESR Signal Intensity Variation with DoseESR Signal Intensity Variation with Dose
340 342 344 346 348 350 352
Apple
5.0 kGy
4.0 kGy
3.0 kGy
2.0 kGy
1.0 kGy
g = 2.0202 g = 1.9852
Magnetic Field (mT)
LIN/COPPE/UFRJ
ESR Spectra of tomato irradiated with additive dosesESR Spectra of tomato irradiated with additive doses
1200 Gy
950 Gy
700 Gy
450 Gy
200 Gy
2 mT
Magnetic Field
(Intensity/Gy) MDDose (Gy) * Cellulose (g/100g)
Kiwi 5.49 0.08 94 0.94Papaya 4.97 0.19 104 0.72Tomato 4.22 0.22 112 0.49Strawberry 1.92 0.23 384 0.48Apple 2.40 0.34 238 0.56Pineapple 3.75 0.37 146 0.60Pumpkin 1.22 0.16 396 0.47Carrot 2.28 0.28 222 0.54
* Calculated as the dose necessary to introduce a signal twice the background intensity for non-irradiated samples.
LIN/COPPE/UFRJ
ESR Sensitivity for Different ProductsESR Sensitivity for Different Products
LIN/COPPE/UFRJ
Dose Determination - Additive dosesDose Determination - Additive doses
-1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.50
1000
2000
3000
4000
5000
6000
7000
8000
9000 Pineapple irradiate with 0.5 Gy
Linear Regression
Y = 1638.54 + 2913.58 * X
r = 0.998
oD = 0.56 Gy
ESR Intensity (au)
Dose (Gy)
-1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.50
1000
2000
3000
4000
5000
6000Carrot irradiate with 0.5 Gy
0D = 0.49 Gy
Linear Regression
Y = 929.99 + 1896.74 * X
r = 0.9911
ESR Intensity (au)
Dose (Gy)
LIN/COPPE/UFRJ
ESR Intensity DecayESR Intensity Decay
0 2 4 6 8 10 12
1500
2000
2500
3000
3500
ES
R In
ten
sity
(a
u)
Weeks
0 10 20 30 40 500
1000
2000
3000
4000
5000
6000
7000
Carrot Strawberry
ES
R I
nten
sity
(au
)
Days
LIN/COPPE/UFRJ
0 200 400 600 800 1000 1200-2000
0
2000
4000
6000
8000
10000
300 Gy
200 Gy
150 Gy
100 Gy
NI
E
SR
Int
ensi
ty (
au)
Chanel
OnionsOnions
LIN/COPPE/UFRJ
GarlicGarlic
342 344 346 348 350 352 354
-2000
0
2000
4000
6000
8000
10000
Y
Axi
s T
itle
Magnetic Field (mT)
LIN/COPPE/UFRJ
Food Irradiation ResearchFood Irradiation Research
EMBRAPA
Fruits and other vegetal products
FACULDADE DE MEDICINA VETERINÁRIA - UFF
Frog legs; oyster; mussel; crab;
LIN/COPPE/UFRJ
Food Irradiation ResearchFood Irradiation Research
FACULDADE DE MEDICINA VETERINÁRIA - Nova Iguaçu
Chicken; Sausage; Beef; Cheese.