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Radiation Resistance of Enzymes in Foods Irradiated Against Microbial Damage; Radioresistance des Enzymes dans les Denrees Alimentaires Irradiees pour les Proteger Contre les Alterations Dues a des Bacteries; Radiatsionnaya ustojchivost' ehnzimov v pishchevykh produktakh,obluchennykh protiv vrednogo vozdejstviya mikrobov; Radiorresistencia de las Enzimas en los Alimentos Irradiados

Abstract

Most enzymes which play a role in the storage, processing and preservation of food are rather resistant to ionizing radiations. Generally speaking, their in situ radio-resistance is about an order of magnitude higher than that of the microorganisms causing spoilage or public health hazards. Thus, radiation doses adequate to microbiological stabilization, and at present considered just feasible economically, are insufficient to prevent enzymatic deterioration. Many attempts have already been made to inactivate enzymes in food by radiation but, judging by the relative failure of most of these efforts, much more background information seems to be necessary to deal with the problem on a more rational basis. To date, work in radiation enzymology has, to a large extent, been carried out in systems of medical interest, generally giving results not readily transposable to food systems. In the past (a) the mechanism of inactivation, as well as the roles of (b) enzyme concentration, (c) water activity of the medium, (d) oxygen concentration, (e) pH and (f) temperature, have been studied most intensively. This is reviewed in the paper. Since, in the majority of the reported experiments, the degree of purity of the enzyme has not been stated (or known, for that matter  More>>
Authors:
Vas, K. [1] 
  1. Joint FAO/IAEA Division of Atomic Energy in Agriculture, International Atomic Energy Agency, Vienna (Austria)
Publication Date:
Nov 15, 1966
Product Type:
Conference
Report Number:
IAEA-SM-73/12
Resource Relation:
Conference: International Symposium on Food Irradiation, Karlsruhe, Federal Republic of Germany (Germany), 6-10 Jun 1966; Other Information: 51 refs.; Related Information: In: Food Irradiation. Proceedings of the International Symposium on Food Irradiation| 979 p.
Subject:
61 RADIATION PROTECTION AND DOSIMETRY; ANIMAL TISSUES; CONTROL; ENZYMES; FAILURES; FOOD PROCESSING; HAZARDS; IMPURITIES; INACTIVATION; IRRADIATION; MICROORGANISMS; OXYGEN; PRESERVATION; PUBLIC HEALTH; RADIATION DOSES; SENSITIVITY; SENSITIZERS
OSTI ID:
22118875
Research Organizations:
International Atomic Energy Agency, Vienna (Austria); Food and Agricultural Organization of the United Nations, Rome (Italy)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
Other: ISSN 0074-1884; TRN: XA13M2039075511
Submitting Site:
INIS
Size:
page(s) 253-263
Announcement Date:
Aug 08, 2013

Citation Formats

Vas, K. Radiation Resistance of Enzymes in Foods Irradiated Against Microbial Damage; Radioresistance des Enzymes dans les Denrees Alimentaires Irradiees pour les Proteger Contre les Alterations Dues a des Bacteries; Radiatsionnaya ustojchivost' ehnzimov v pishchevykh produktakh,obluchennykh protiv vrednogo vozdejstviya mikrobov; Radiorresistencia de las Enzimas en los Alimentos Irradiados. IAEA: N. p., 1966. Web.
Vas, K. Radiation Resistance of Enzymes in Foods Irradiated Against Microbial Damage; Radioresistance des Enzymes dans les Denrees Alimentaires Irradiees pour les Proteger Contre les Alterations Dues a des Bacteries; Radiatsionnaya ustojchivost' ehnzimov v pishchevykh produktakh,obluchennykh protiv vrednogo vozdejstviya mikrobov; Radiorresistencia de las Enzimas en los Alimentos Irradiados. IAEA.
Vas, K. 1966. "Radiation Resistance of Enzymes in Foods Irradiated Against Microbial Damage; Radioresistance des Enzymes dans les Denrees Alimentaires Irradiees pour les Proteger Contre les Alterations Dues a des Bacteries; Radiatsionnaya ustojchivost' ehnzimov v pishchevykh produktakh,obluchennykh protiv vrednogo vozdejstviya mikrobov; Radiorresistencia de las Enzimas en los Alimentos Irradiados." IAEA.
@misc{etde_22118875,
title = {Radiation Resistance of Enzymes in Foods Irradiated Against Microbial Damage; Radioresistance des Enzymes dans les Denrees Alimentaires Irradiees pour les Proteger Contre les Alterations Dues a des Bacteries; Radiatsionnaya ustojchivost' ehnzimov v pishchevykh produktakh,obluchennykh protiv vrednogo vozdejstviya mikrobov; Radiorresistencia de las Enzimas en los Alimentos Irradiados}
author = {Vas, K.}
abstractNote = {Most enzymes which play a role in the storage, processing and preservation of food are rather resistant to ionizing radiations. Generally speaking, their in situ radio-resistance is about an order of magnitude higher than that of the microorganisms causing spoilage or public health hazards. Thus, radiation doses adequate to microbiological stabilization, and at present considered just feasible economically, are insufficient to prevent enzymatic deterioration. Many attempts have already been made to inactivate enzymes in food by radiation but, judging by the relative failure of most of these efforts, much more background information seems to be necessary to deal with the problem on a more rational basis. To date, work in radiation enzymology has, to a large extent, been carried out in systems of medical interest, generally giving results not readily transposable to food systems. In the past (a) the mechanism of inactivation, as well as the roles of (b) enzyme concentration, (c) water activity of the medium, (d) oxygen concentration, (e) pH and (f) temperature, have been studied most intensively. This is reviewed in the paper. Since, in the majority of the reported experiments, the degree of purity of the enzyme has not been stated (or known, for that matter to the authors themselves), and since, on the other hand, radio-modifying substances are known to exert a decisive influence on the radiation inactivation of enzymes, it is felt that much more work is still needed on radio-protectors and radiation sensitizers in combination with highly-purified enzymes. The usual great radio-sensitivity of high-purity enzymes and the contrasting extreme resistance of enzymes in the tissues and in their unpurified extracts certainly indicate the need for finding the reasons for this difference in order to facilitate possibly a rational approach of controlling enzyme activity in food irradiation. In this way, perhaps some novel ''combination method'' can eventually be developed in addition to the combined methods which have already been put forward to control enzyme action, i.e. combining irradiation (a) with heating (b) with refrigeration and (c) with physiological methods (e.g. control of glycogenolysis) the status of all of which is briefly discussed in the paper. (author) [French] La plupart des enzymes qui jouent un role dans l'emmagasinage, la preparation et la conservation des denrees alimentaires possedent une certaine resistance aux rayonnements ionisants. D'une maniere generale, leur radioresistance in situ est superieure d'un ordre de grandeur environ a celle des micro-organismes qui causent des alterations ou presentent des risques pour la sante publique. Ainsi, les doses de rayonnements suffisantes pour assurer une stabilisation microbiologique - et considerees actuellement comme se situant a la limite de la rentabilite - sont insuffisantes pour empecher la deterioration par les enzymes. Maintes tentatives ont deja ete faites pour rendre inactifs, au moyen de rayonnements, les enzymes contenus dans les aliments; cependant, a en juger par l'echec relatif de la plupart d'entre elles, il semble qu'il faille reunir beaucoup plus de donnees de base pour s'attaquer au probleme d'une facon plus rationnelle. Jusqu'a present, les etudes relatives a la radioenzymologie-ont porte en grande partie sur des systemes presentant un interet medical, ce qui donnait generalement des resultats qui n'etaient pas aisement trans- posables sur le plan des denrees alimentaires. Dans le passe, on s'etait avant tout penche sur a) le mecanisme de l'inactivation, ainsi que sur le role de b) la concentration des enzymes, c) l'activite de l'eau contenue dans le milieu considere, d) la teneur en oxygene, e) le pH et f) la temperature. Le memoire passe en revue ces travaux. Etant donne que la plupart des communications relatives aux experiences effectuees n'indiquent pas le degre de purete de l'enzyme (d'ailleurs inconnu des auteurs eux-memes) et puisque, d'autre part, on sait que les substances radiomoueificatrices exercent une influence determinante sur la radioinactivation des enzymes, l'auteur estime qu'il faudrait entreprendre des etudes plus poussees sur les radioprotecteurs et les radiosensibilisateurs avec des enzymes fortement purifies. La grande radiosensibilite qui caracterise ordinairement les enzymes tres purs et, par contraste, l'extreme resistance des enzymes dans les tissus et dans leurs extraits non purifies, demontrent la necessite de determiner les raisons de cette difference, ce qui facilitera sans doute la mise au point d'une methode, rationnelle permettant de controler l'activite des enzymes dans le cadre de l'irradiation des aliments. De cette maniere, on pourrait peut-etre mettre au point une 'methode mixte' inedite, laquelle viendrait s'ajouter aux methodes combinees qui ont deja ete elaborees pour le controle de l'action des enzymes; en d'autres termes, on combinerait l'irradiation avec a) le traitement thermique, b) la refrigeration et c) les methodes physiologiques (par exemple, controle de la giycogenolyse). Le memoire fait brievement le point des applications de ces divers procedes. (author) [Spanish] La mayor parte de las enzimas que actuan durante el almacenamiento, la elaboracion y la conservacion de los alimentos son bastante resistentes a las radiaciones ionizantes. Por lo general, esa resistencia en su propio medio suele ser superior en un orden de magnitud a la de los microorganismos que causan la descomposicion o la alteracion de los alimentos. Debido a ello, dosis de irradiacion suficientes para la estabilizacion microbiologica y cuya aplicacion se considera actualmente apenas economica, no impiden la deterioracion causada por las enzimas. Se ha intentado ya muchas veces inactivar por irradiacion las enzimas de los alimentos, pero a juzgar por el escaso exito de la mayor parte de los ensayos efectuados, es necesario estudiar mucho mas a fondo los aspectos generales de la cuestion a fin de poder abordar el problema de una manera mas racional. Los estudios radioenzimologicos realizados hasta ahora tenian en su mayor parte finalidades medicas; no es facil extrapolar sus resultados a la conservacion de los alimentos. Las cuestiones mas estudiadas han sido: a) el mecanismo de la inactivacion y el papel que desempena, b) la concentracion de las enzimas, c) la actividad del agua en el medio, d) la concentracion de oxigeno, e) el pH y f) la temperatura. En la memoria se examinan todos estos puntos. Como en la mayoria de los experimentos publicados no se indica el grado de pureza de la enzima (desconocido a veces por los mismos autores) y como por otra parte se sabe que las sustancias radiomodificadoras ejercen una influencia decisiva sobre la radioinactivacion de las enzimas, el autor considera necesario reunir muchos mas datos sobre los agentes radioprotectores y radiosensibilizadores en relacion con enzimas de alta pureza. El contraste entre la elevada radiosensibilidad que suelen tener las enzimas de gran pureza y la extremada resistencia que se observa en ellas cuando se encuentran en los tejidos o en extractos sin purificar, indica la necesidad de averiguar las causas del fenomeno, lo que permitiria quiza enfocar mejor el problema de la inactivacion de esos agentes. Es posible que entonces se encuentre un ' metodo combinado' parecido a los que se han propuesto ya para reducir la accion de las enzimas: irradiacion combinada a) con un tratamiento termico, b) con la refrigeracion o c) con metodos fisiologicos (control de la glicogenolisis, por ejemplo). En la memoria se examina cada uno de estos metodos. (author) [Russian] Bol'shinstvo jenzimov, kotorye imejut opredelennoe znachenie pri hranenii, obrabotke i konservacii pishhevyh produktov, javljajutsja dovol'no stojkimi k ionizirujushhimu oblucheniju. Govorja voobshhe, ih radioustojchivost' in situ primerno na odin porjadok velichiny vyshe ustojchivorti mikroorganizmov, javljajushhihsja prichinoj porchi pishhevyh produktov ili pred- stavljav shhjh opasnost' dlja zdorov'ja naselenija. Takim obrazom, dozy obluchenija, dostatochnye dlja,mikrobiologicheskoj stabilizacii i rassmatrivaemye v nastojashhee vremja kak celesoobraznye s jekonomicheskoj tochki zrenija, ne dostatochny dlja predotvrashhenija jenzimaticheskoj porchi. Uzhe predprinjato mnogo popytok putem obluchenija sdelat' jenzimy v pishhevyh produktah neaktivnymi, no sudja po otnositel'nym neudacham bol'shinstva jetih popytok, mozhno polagat', chto dlja reshenija jetoj problemy na bolee racional'noj osnove neobhodimo imet' znachitel'no bol'she informacii. Do nastojashhego vremeni raboty v oblasti radiacionnoj jenzimologii provodilis' bol'shej chast'ju v oblastjah, predstavljajushhih interes dlja mediciny, i, kak pravilo, davali rezul'taty, kotorye nel'zja bylo neposredstvenno rasprostranjat' na sferu pishhevyh produktov. V proshlom naibolee intensivno izuchalis': 1) mehanizm inaktivacii, a takzhe ego rol'; 2) koncentracija jenzimov, 3) vodnaja aktivnost' sredy;4) kislorodnaja koncentracija; 5) pH i 6) temperatury. Doklad soderzhit obzor jetih rabot. Poskol'ku v bol'shinstve opublikovannyh rabot ne privodilos' dannyh otnositel'no stepeni chistoty jenzimov (ili oni ne byli izvestny samim avtoram) i t.k., s drugoj storony, izvestno, chto radioizmenjajushhie veshhestva okazyvajut opredeljajushhee vlijanie na inaktivaciju jenzimov s pomoshh'ju izluchenij, schitaetsja, chto neobhodimo provesti bol'shie raboty v oblasti radiacionno-zashhitnyh veshhestv i radiacionnyh sensibilizatorov v sochetanii s vysokoochishhennymi jenzimami. Obychno bol'shaja radiochuvstvitel'nost' vysokoochishhennyh jenzimov i kontrastirujushhaja s jetim chrezvychajnaja ustojchivost' jenzimov v tkanjah i v neochishhennyh jekstraktah ukazyvjut na neobhodimost' najti prichiny jetogo razlichija s tem, chtoby, po vozmozhnosti, vybrat' celesoobraznyj podhod dlja reshenija voprosa o kontrole za aktivnost'ju jenzimov pri obluchenii pishhevyh produktov. Takim putem so vremenem, vozmozhno, udastsja razrabotat' novyj 'kombinirovannyj metod' v dopolnenie k kombinirovannym metodam, kotorye uzhe byli predlozheny dlja kontrolja za dejstviem jenzimov, t.e. sochetanie obluchenija 1) s nagrevom, 2) s zamorazhivaniem i 3) s fiziologicheskimi metodami (naprimer, kontrol' v otnoshenii glikogenoliza), raboty s kotorymi kratko obsuzhdeny v doklade. (author)}
place = {IAEA}
year = {1966}
month = {Nov}
}