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.