Volume 1

First report / Committee on Nutrition in the Colonial Empire.

  • Great Britain. Committee on Nutrition in the Colonial Empire.
Date:
1939
Catalogue details

Licence: Public Domain Mark

Credit: First report / Committee on Nutrition in the Colonial Empire. Source: Wellcome Collection.

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    vs, The most satisfactory method for the bulk storage of grain is in large concrete or metal tanks which can be hermetically sealed and which are also provided with facilities for fumigation in the event of the contents being attacked by insects. Grain is, how- ever, often stored in bags in large stores. It is important that such stores should always be made rat-proof since other- wise a large amount of damage may occur and there is the added danger of providing foci for rat-borne diseases, particularly plague. Grain stored in bags is also much subject to attack by insects. It is very difficult to guard against this, though recent experiments in Malaya indicate that an addition of 5 per cent. of quicklime to rice will prevent weevil attack. In general storage in bags, though for various reasons it may often have to be used, is not so effective as storage in concrete or metal tanks. 207. Indeed as a general rule it may be said that wherever possible stored products, whether dried or not, should be kept in airtight containers. Not only will bacterial and fungal activity thus be reduced to a minimum, but also there will be no danger of attack by insects. If the product is free from pests when sealed in the container it will be free when the seal is broken. If the product stored is living, e.g. grain or seeds, then respiration will take place in the container. In air- tight containers, as a result of progressive replacement by car- bon dioxide of the oxygen in the air between the stored pro- ducts, the rate of respiration is progressively retarded. For this reason, and because of the dry environment, the life of the grain is prolonged. At the same time the accumulation of carbon dioxide will first check the activity of any insect pests that may be amongst the grain and then will asphyxiate them. 208. If a container is airtight it will very often be ratproof. If it is not, means must also be found of affording protection against attack by rats, since not only will they cause direct loss but also, by damaging the container, they will permit the entry of damp air and insect pests. 209. If the stored product has to be transported, this should be taken into account. If transport is by head porterage, bicycle or lorry, then the type of storage should be adapted to this method. For example, if fish is the commodity in question and head porterage or the bicycle the method of distribution, then the storage container employed should not exceed in size one load. This is not always practicable but the principle should be borne in mind. 210. Drying may be accompanied by chemical treatment of the article to improve its appearance and keeping qualities and to conserve its nutritive value. Sulphur dioxide, for example, is employed in California where it is desired to preserve fruit