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Identification of irradiated fresh fruits
Abstracts
A NEW RESEARCH
1021
PROGRAM ON EFFECTS ON PLANT CELLS
OF GAMMA
RAYS
P. BOISSEAU, C. LARRIGAUDIERE,J. L. MONTILLET and C. TRIANTAPHYLIDES DB/SRA CEN Cadarache, F-13108 Saint Paul Lez Durance, France Abstract-The French Atomic Energy Commission started in 1962 studies on food irradiation, in its research center of Cadarache. The first 20 years were mainly devoted to radiochemistry and toxicology. Since 1985, we have been interested in basic research, especially on fruits and vegetables. The following research program started in 1987 with 3 scientists and a long term fellowship and has an increasing importance that will enable us to employ 2 new scientists next year. The aim of Laboratory of Cell Radiobiology of the French Atomic Energy Commission is to study the effects of y-rays on the physiology and metabolism of plant cell and in particular: -the impact of y-rays on the mechanisms of maturation and senescence in plant physiology; -the impact of y-rays on interactions between plants and microorganisms.
EFFECT OF HEAT, IRRADIATION, PACKAGING AND THEIR COMBINATION ON THE KEEPING QUALITY OF TOMATOES ARTIFICIALLY INFECTED WITH BOTR YTZS CZNEREA D. Is. LANGERAK, M. EL-BUZEDI, TH. C. WOLTERS and D. GOA State Institute for Quality Control of Agricultural Products (RIKILT), P.O. Box 230, 6700 AE Wageningen, The Netherlands Abstract-Tomatoes cannot be stored for long at ambient temperature because of overripening and rotting. Irradiation offers the possibility to delay ripening and extend the shelf-life but cannot control mould growth completely within the dose range suitable for tomatoes. Tomatoes artificially infected with Botrytis cinerea were dipped in hot water (47°C for 5 min), packed (ooen nolvvinvlchloride foil) and irradiated (0, 0.5, 1.0 and 1.5 kGv). _, The . . with ._ . travs and travs wraoned combination of heat, packaging with polyvinylchloride foil and irradiation with 1.5 kGy was very effective in control of rot.
IDENTIFICATION
OF IRRADIATED
FRESH
FRUITS
E. KOVACS’ and A. KERESZTE? ‘Central Food Research Institute, H-1525 Budapest, Herman Otto u. 15, Hungary and *E6tvbs Lorand University, Department of Plant Anatomy, 1088 Budapest, Mtizeum krt. 4/A, Hungary Abstract-During ripening and senescene starch decomposes in the apple. We have separately studied the skin and flesh of apple. It was established that a short time after irradiation (4-5 days) starch synthesis was induced in the skin and flesh of apple. (Gloster, Mutsu, Golden Delicious). The starch was preserved in the skin of the irradiated apple for at least 3 months (apple was stored at I-2°C 80-90% RH) (Kovacs et al., 1988). In our present work on one hand the sugars (fructose, glucose, sucrose) were studied as a function of irradiation dose (0, 0.5, 1.2and 5 kGy) in apple (Golden Delicious) skin and flesh by HPLC technics, on the other hand the starch content was determined chemically and by an ultrastructural method. The investigations were carried out with 6 weeks old apples (stored at 16°C g&90% RH). 5 days after irradiation all samples were checked by the starch iodine test. Starch synthesis was induced as a function of irradiation treatment in the flesh of the apple. Six weeks later this test was repeated and it was established that the starch decomposed in all samples except 5 kGy. The analysis of sugar showed that the glucose concentration increased in the flesh with the increasing radiation doses. Starch could not be observed in the flesh of apples, neither chemically nor with ultrastructural investigations. In the skin the starch content increased as function of radiation treatment. 1 kGy dose caused a significant effect (P > 99%) on the synthesis of starch. At the same time the glucose fructose and sucrose contents increased up to 1 and 2 kGy, respectively afterwords they decreased (Kovacs et al., 1989). Summarizing our results: (1) Starch synthesis is significantly induced by irradiation (1 kGy) in the skin of apple. (2) This change is observed in a short time after irradiation (4-5 days) and is preserved for a longer period. (3) This change is independent of the apple variety. Data will be published in Food Microstructure (Kov~cs et al., 1988, 1989).
A NEW RESEARCH
1021
PROGRAM ON EFFECTS ON PLANT CELLS
OF GAMMA
RAYS
P. BOISSEAU, C. LARRIGAUDIERE,J. L. MONTILLET and C. TRIANTAPHYLIDES DB/SRA CEN Cadarache, F-13108 Saint Paul Lez Durance, France Abstract-The French Atomic Energy Commission started in 1962 studies on food irradiation, in its research center of Cadarache. The first 20 years were mainly devoted to radiochemistry and toxicology. Since 1985, we have been interested in basic research, especially on fruits and vegetables. The following research program started in 1987 with 3 scientists and a long term fellowship and has an increasing importance that will enable us to employ 2 new scientists next year. The aim of Laboratory of Cell Radiobiology of the French Atomic Energy Commission is to study the effects of y-rays on the physiology and metabolism of plant cell and in particular: -the impact of y-rays on the mechanisms of maturation and senescence in plant physiology; -the impact of y-rays on interactions between plants and microorganisms.
EFFECT OF HEAT, IRRADIATION, PACKAGING AND THEIR COMBINATION ON THE KEEPING QUALITY OF TOMATOES ARTIFICIALLY INFECTED WITH BOTR YTZS CZNEREA D. Is. LANGERAK, M. EL-BUZEDI, TH. C. WOLTERS and D. GOA State Institute for Quality Control of Agricultural Products (RIKILT), P.O. Box 230, 6700 AE Wageningen, The Netherlands Abstract-Tomatoes cannot be stored for long at ambient temperature because of overripening and rotting. Irradiation offers the possibility to delay ripening and extend the shelf-life but cannot control mould growth completely within the dose range suitable for tomatoes. Tomatoes artificially infected with Botrytis cinerea were dipped in hot water (47°C for 5 min), packed (ooen nolvvinvlchloride foil) and irradiated (0, 0.5, 1.0 and 1.5 kGv). _, The . . with ._ . travs and travs wraoned combination of heat, packaging with polyvinylchloride foil and irradiation with 1.5 kGy was very effective in control of rot.
IDENTIFICATION
OF IRRADIATED
FRESH
FRUITS
E. KOVACS’ and A. KERESZTE? ‘Central Food Research Institute, H-1525 Budapest, Herman Otto u. 15, Hungary and *E6tvbs Lorand University, Department of Plant Anatomy, 1088 Budapest, Mtizeum krt. 4/A, Hungary Abstract-During ripening and senescene starch decomposes in the apple. We have separately studied the skin and flesh of apple. It was established that a short time after irradiation (4-5 days) starch synthesis was induced in the skin and flesh of apple. (Gloster, Mutsu, Golden Delicious). The starch was preserved in the skin of the irradiated apple for at least 3 months (apple was stored at I-2°C 80-90% RH) (Kovacs et al., 1988). In our present work on one hand the sugars (fructose, glucose, sucrose) were studied as a function of irradiation dose (0, 0.5, 1.2and 5 kGy) in apple (Golden Delicious) skin and flesh by HPLC technics, on the other hand the starch content was determined chemically and by an ultrastructural method. The investigations were carried out with 6 weeks old apples (stored at 16°C g&90% RH). 5 days after irradiation all samples were checked by the starch iodine test. Starch synthesis was induced as a function of irradiation treatment in the flesh of the apple. Six weeks later this test was repeated and it was established that the starch decomposed in all samples except 5 kGy. The analysis of sugar showed that the glucose concentration increased in the flesh with the increasing radiation doses. Starch could not be observed in the flesh of apples, neither chemically nor with ultrastructural investigations. In the skin the starch content increased as function of radiation treatment. 1 kGy dose caused a significant effect (P > 99%) on the synthesis of starch. At the same time the glucose fructose and sucrose contents increased up to 1 and 2 kGy, respectively afterwords they decreased (Kovacs et al., 1989). Summarizing our results: (1) Starch synthesis is significantly induced by irradiation (1 kGy) in the skin of apple. (2) This change is observed in a short time after irradiation (4-5 days) and is preserved for a longer period. (3) This change is independent of the apple variety. Data will be published in Food Microstructure (Kov~cs et al., 1988, 1989).