88-6h69 4851903 0051815 5 4-89-15 ISO INTERNATIONAL STANDARD 6949 First edition 1988-11-01 INTERNATIONALORGANIZATION FORSTANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION Fruits and vegetables - Principles and techniques of the controlled atmosphere method of storage Fruits et legumes - Principes et techniques de la methode d'entreposage en atmosphere controlée Reference number ISO 6949: 1988 (E) Copyright International Organization for Standardization Not for Resale ga-6hb9 4851903 00518167 ISO 6949 : 1988 (E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out through Iso technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with Iso, also take part in the work. Iso collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISo Council. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 6949 was prepared by Technical Committee ISO/TC 34, Agriculturalfoodproducts. Annex A of this International Standard is for information only. @International Organization for Standardization, 1988 Printed in Switzerland licensefromIHS Not for Resale 4851903 0051817 6949-88 ISO 6949 : 1988 (E) Introduction The extension of the keeping period for fruits and vegetables, with minimum loss, to the long term is closely linked to the rate of the metabolic processes occurring in the products and the rate of development of pathogenic micro-organisms and physiological diseases. The use of cold storage, with control of the relative humidity of the air in the store, results in the reduction of the respiration rate and of transpiration, as well as of the development of some'diseases. Better results may be obtained, however, by the storage of fruits and vegetables in controlled atmospheres, which is based on the maintenance of the temperature and of the relative humidity at optimal values, and also invoives the regulation of the gas com- position in the store. Storage in controlled atmospheres, combining the effects of three basic factors (temperature, relative humidity and gas composition), leads generally to a reduction in metabolic activity and, in the case of climacteric products (such as apples, pears, bananas and tomatoes), possibly to a deiay in the appearance of the onset of the climacteric period. The low-oxygen atmosphere reduces ethylene production. and the combination of the low oxygen and high carbon dioxide levels reduces the effects of ethyiene. Conse- quently, there is a delay in ripening, the nutritive value and the appearance for sale are maintained and the keeping period of the product can be extended. Further, as a result of the reduction in oxygen content and increase in carbon dioxide content, the development of pathogenic micro-organisms and the appearance of some physiological disorders may be retarded. The products stored in controlled atmospheres shall be of varieties and quality different from those of products stored under normal conditions. Copyright International Organization for Standardization