STORAGE OF APPLES.

New Zealand Herald, Volume LXIX, Issue 21164, 22 April 1932, Page 15

STORAGE OF APPLES.

COOKERS KEEP A YEAR.

CONTROL OF THE GASES. WORK BY SCIENTISTS. [from our own correspondent.] LONDON, March 3. Research work regarding iho storing of apples has gone on steadily, thanks to the fifiancial assistance of the Empire Marketing Board, over since it was found out that picked apples are living organisms and continue that life even under cool storage conditions. Money was found by the hoard to erect, a laboratory at East Mailing, near Maidstone. The Mailing Research Station for fruit is an independent institution run by the Kent fruit farmers with assistance from tho Government. The Ditton Laboratory, just outside the grounds, is a Government institution under the Food Investigation Board of tho Department of Scientific and Industrial Research. Tlie department to-day invited a number of journalists to visit the Ditton Laboratory to v hear something about tlie new method known as "gas storage" for fruit. The object of the investigation is to encourage and to provide a safeguard for the English growers. They ask: Why do we buy all these apples from overseas instead of growing them ourselves? English growers already produce something like three or four hundred thousand tons a j r ear, but most of these are disposed of directly from tho tree. The "gas storage" system will enable tho homo grower to keep his apples in store and distribute them more profitably over a longer period. Apples from Ship's Hold.

The experts were asked if apples taken from a ship's hold carried in the ordinary way could bo put into "gas storage" and kept indefinitely on this side. They could not give a definite reply, for they have so far concentrated 011 three English varieties and have only spoken with conclusive authority on one variety of cooking apple—Bramley's Seedling. They know that if Bramley's Seedling is kept at a certain temperature with the correct proportions of oxygen and carbon dioxide gas, the apples will keep for a long period. They have actually kept them for 13 months and the fruit has been mistaken for fruit of the current season. Visitors at Ditton Laboratory to-day had the opportunity of inspecting the experimental storerooms. Apples of known history are gathered from the Mailing Research Station for the experiments. Cylinders of gas are used to provide the proper atmosphere in the storage cabinets. The supply through pipes to the 12 cabinets is ingeniously arranged and the temperature control is, of course, perfect. Gas Combinations,

Similar apples are stored in four cabinets in three different chambers. The first chamber is at a temperature of 1 dcg. C (34 cleg. F.); the second chamber is at a temperature of 4 deg. C. (40 dcg. F.); and the third chamber is at 10 deg. C. (50 deg. F.) One cabinet in each of the chambers is a control cabinet containing a mixture similar to ordinary air. The other three cabinets in each chamber contain 5 per cent., 10 per cent, and 15 per cent, of carbon dioxido respectively. All three in the first chamber contain 2.5 per cent, of oxygen; all three in the second chamber 5 per cent, of oxygen; and all three in the third chamber contain 10 per cent, of oxygen. In each case the full percentage of volume is made up with air. There are thus nine different combinations with which to experiment. Dr. F. Kidd and Dr. Cyril West are now able to tell the producers the most suitable temperature and the most suitable mixture of oxygen and carbon dioxide in which to keep Bramley's Seedlings, the most popular of the English cooking apples. They are experimenting with two other varieties—one Cox's Orange Pippins—and in due course they will bo able to state definitely at what temperature and what proportion of the gases is most suitable for these other two varieties. Each variety will have to be tested in turn before the results are proclaimed. System Inexpensive.

At the, present time there are in Kent three stores fitted with gas control and some hundreds of tons of English apples are being kept in store. When applied to commercial stores the system is not expensive. It has been found that largo cool stores, if fairly air-proof to begin with, can bo made sufficiently air-proof for gas control if the walls are treated with vaseline. A commercial cool store with a capacity of 500 tons may be fitted with tho necessary ventilators and testing apparatus for an outlay of £4O. The attendant, by opening and shutting ventilators, may ensure that insido the store the proportions of oxygen and carbon dioxide are correct, the latter gas, of course, being generated by tho apples themselves.

This system should certainly enable the English growers to get tho maximum of profit from their crops and encourage them to plant more trees and produce more apples. Whether tho system may bo applied to imported apples has yet to bo teen. It may be suggested, however, that the system might very well be adopted in the Dominions themselves, not in connection with the export trade, but in connection with tho domestic supply. No doubt the Dominions arc at a greater disadvantage in regard to supplies than Great Britain itself. Tho latter gets its apples fro.| both hemispheres and defies tho seasons. The Dominions have to rely upon the local produco after the export trade has been satisfied. Isy the installation of this gas storago system it would seem that tho people of tho producing countries could rely on having apples at a reasonable price all the year round.