GAS METHOD FOR FRUIT STORAGE.

Horowhenua Chronicle, 4 August 1931, Page 7

GAS METHOD FOR FRUIT STORAGE.

NEW BRITISH INVENTION WILL IMPROVE APPLE QUALITY.

SCIENTIFIC TRIUMPH TO BENE-

FIT NEW ZEALAND.

(From a Special Correspondent)

London, June 18th

An entirely new method of storing fruit, invented by British scientists at Cambridge, is now (being tried out ■commercially on a fruit-farm in Kent. Apples which were put into store in the autumn came out in such good condition six months later that they realised top prices on the London market.

This method is known as “gas storage." If it works out as well in practice as in the laboratory, it will have the double advantage of effecting large economies over cold storage, both on capital outlay and running costs, and of keeping the fruit in better condition.

< So far it can only be used for certain varieties of apples. (Scientists have yet to llnd out whether the principles can be applied to other varieties ’ and types of fruit. They are busy on the problem at the Low Temperature .Research (Station at Cambridge where the method was worked out with the help of grants from the Empire Marketing Board. “G-as Stores" for New Zealand. New Zealand scientists are already interested in the possibilities of “gas storage." One of the first problems will be to find whether New Zealand varieties do as well as Bramleys, Worcester Pearmain, Lane's Prince Albert and the other English apples which thrive on the treatment. The essence of it is that the work is done by the apples themselves instead of by the refrigerator. Fruit like man, gives off a gas, carbon dioxide, which, every apple breathes. out continubusly. A certain amount of this gas acts as a preseravtive and slows down chemical action in the fruit, thus arresting decay. The gas really has the same effect as cold storage —namely, to slow down respiration and chemical activity. Too much of it, however, suffocates the fruit, just as a man is suffocated if he is buried alive. Smeared with Vaseline.

All you need to make a “gas store” is a well-ibuilt shed with thick w r alls, and a large quantity of vaseline. A “,gas store,” unlike a cold store, does not need expensive insulation. A refrigerator plant is necessary to lower the temperature of the fruit when it is first put into store,- but after this it need only bo run for a few hours a day. There are two commercial “gas stores,” at present, in Kent. A leading fruit-farmer has transformed his casthouse (one of those picturesque round brick kilns used for drying hops which are as much part of the friendly Kentish countryside as windmills are of the Dutch landscape) into a store divided into six rooms. He has covered the inside of the ■walls with iron sheeting and smeared roof and walls with a thick layer of vaseline. The stores are as nearly airtight as it is possible for them to be. They hold, in all, about 12,000 bushels. No Wastage.

I watched thousands of baskets, each containing a bushel, being taken out and loaded up for market. The apples were in tip-top condition. They were all Bramlcy’s seedlings, which is the most important variety pf English apple and comprises about threequarters of the crop in the southeastern fruit belt, “There is not more than 2 to 3 per cent, wastage,” the grower told mo, “This is something like half the usual amount.”

The correct concentration of carbon dioxide is about 10 per cent, and the temperature should be kept steady at 41 degrees or 42 degrees IFahernheit. During the winter it is often unnecessary to run the refrigerator for days at a time. The exact proportion of 002 in the atmosphere in any of the chambers is shown on a dial outside the store. If it rises too high, a ventilator is opened, to let some more air in. But no one enters the store, once it is sealed in October, till it is opened up in the spring. Two new “gas stores,” I was told, are likely to be put into operation next season. Will It Work In New Zealand?

But many problems still remain for the scientist. Although the store is completely sealed, winds have a marked effect on the atmosphere inside. A strong wind seems to drive away the carbon dioxide. Gas stores, scientists say, should bo placed in sheltered spots. New Zealand growers, however, have another problem; will “gas storage” work for New Zealand varieties? So far, most of the apples commonly grown in New Zealand and the other Dominions have not been tested. The British Department of Scientific and Industrial Research has built/ with money from the Empire Marketing Board, the largest experimental cold storage research centre in the world. This is the Ditton Laboratory, at East Mailing, in Kent, where these and other problems connected with fruit and vegetable storage arc to be tackled. Pear Problems. They also hope to experiment with gas storage on- other kinds of fruits. Pears, for instance, are notoriously difficult to manage in cold store, and gas storage may alter the whole pear situation by enabling the delicate fruit to bo held over without damaging its quality, and by cutting down the present heavy loss from wastage. The flavour of an apple is closely connected, scientists believe, with certain volatile products which it gives off in incredibly minute quantities. They are attempting to isolate these substances, condense them and find out just what gives a Cox ; s Orange Pippin or a Jonathan its distinctive taste. Then, thev hope, more will be known about whether gas storage can be used extensively to ’ improve and cheapen ■storage of New Zealand and other Empire apples.