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ELECTRON SPIN RESSONANCE IDENTIFICATION OF IRRADIATED FOOD

LIN/COPPE/UFRJ. ELECTRON SPIN RESSONANCE IDENTIFICATION OF IRRADIATED FOOD. Prof. Edgar Francisco Oliveira de Jesus * Prof. Ricardo Tadeu Lopes * Dr. Alexandre Malta Rossi **. *Laboratório de Instrumentação Nuclear (Escola de Engenharia/COPPE/UFRJ)

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ELECTRON SPIN RESSONANCE IDENTIFICATION OF IRRADIATED FOOD

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  1. LIN/COPPE/UFRJ ELECTRON SPIN RESSONANCE IDENTIFICATION OF IRRADIATED FOOD Prof. Edgar Francisco Oliveira de Jesus* Prof. Ricardo Tadeu Lopes* Dr. Alexandre Malta Rossi** *Laboratório de Instrumentação Nuclear (Escola de Engenharia/COPPE/UFRJ) **Centro Brasileiro de Pesquisas Físicas (CBPF)

  2. LIN/COPPE/UFRJ H. Delincée - “Analytical methods to identify irradiated food¯¯a review” Radiation Physics Chemistry; 63, 3-6; p.455-458, 2002

  3. LIN/COPPE/UFRJ Electron Spin Resonance (ESR)

  4. LIN/COPPE/UFRJ Radiation Sources • “Brokhawen Portable Cesium Development Irradiator” (BPCDI) - IPE, CETEX., Guaratiba, RJ. • Césio-137 with 3,99 x 1015 Bq (108.000 Ci), in 1969 • Actual dose rate - 30.0 Gy/min • Gammacell 220 Excel - Nordion - Laboratório de Instrumentação Nuclear COPPE/UFRJ • Cobalto-60 with 3.08 x 106 Bq (12,000 Ci), in 2000 • Actual dose rate - 90 Gy/min

  5. LIN/COPPE/UFRJ IPD Irradiator - Frontal view.

  6. LIN/COPPE/UFRJ Gammacell Irradiator

  7. LIN/COPPE/UFRJ ESR Measurements • Bruker ESP300E spectrometer (CBPF) • Bruker EMS104 spectrometer (LIN)

  8. LIN/COPPE/UFRJ Alcoholic Extraction Treatment • 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.

  9. LIN/COPPE/UFRJ Products • Papaya Tomato Kiwi • Apple Pineapple Strawberry • Pear Mango • Pumpkin Carrot Potatoes • Onions Garlic

  10. LIN/COPPE/UFRJ ESR Spectra Irradiated Samples Non-irradiated Samples

  11. LIN/COPPE/UFRJ ESR Signal Intensity Variation with Dose

  12. LIN/COPPE/UFRJ ESR Spectra of tomato irradiated with additive doses

  13. LIN/COPPE/UFRJ ESR Sensitivity for Different Products (Intensity/Gy) MDDose (Gy) * Cellulose (g/100g) Kiwi 5.49  0.08 94 0.94 Papaya 4.97  0.19 104 0.72 Tomato 4.22  0.22 112 0.49 Strawberry 1.92  0.23 384 0.48 Apple 2.40  0.34 238 0.56 Pineapple 3.75  0.37 146 0.60 Pumpkin 1.22  0.16 396 0.47 Carrot 2.28  0.28 222 0.54 * Calculated as the dose necessary to introduce a signal twice the background intensity for non-irradiated samples.

  14. LIN/COPPE/UFRJ Dose Determination - Additive doses

  15. LIN/COPPE/UFRJ ESR Intensity Decay

  16. LIN/COPPE/UFRJ Onions

  17. LIN/COPPE/UFRJ Garlic

  18. LIN/COPPE/UFRJ Food Irradiation Research EMBRAPA • Fruits and other vegetal products FACULDADE DE MEDICINA VETERINÁRIA - UFF • Frog legs; • oyster; • mussel; • crab;

  19. LIN/COPPE/UFRJ Food Irradiation Research FACULDADE DE MEDICINA VETERINÁRIA - Nova Iguaçu • Chicken; • Sausage; • Beef; • Cheese.

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