STORAGE OF FRUIT

Nelson Evening Mail, Volume LXIV, 5 August 1931, Page 3

STORAGE OF FRUIT

NEW BRITISH INVENTION SCIENTIFIC TRrtriWPH ~• J t LONDON, (IrtUi July./, j A'ti entirely/ new gnethod of storing fruit; invented by British scientist# at ' Cambridge, is now being tried out com-! mcrcially on a;- fruit-farm in Kent (writes “The Dominion's” correspondent). Apples which were put into store in the autumn came out in such good condition six months later that they realised toj) 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 tho 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 tjo find out whether the principles can be applied to other varieties and types rif fruit. They are busy on the problem at the low temperature research station at Cambridge, where the method has been worked out with the aid of grants from the Empiro Marketing Board. “GAS STORES” FOR NEW ZEALAND? New Zealand scientists are already interested in- the possibilities of “gas Storage.” One of the first problems will lie to. find whether New Zealand varieties do as well as Bramleys, Worcester Pearmain, Lane’s Prince Albert, and the other English apples which thrive oii 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 continuously. A certain amount of this gas acts as a preservative and slows down chemical action in the fruit, thus arresting decay. The gas really lias the same effect as cold storage—namely, to slow down respiration and chemical activity. Too rriueh of it, however, suffocates 4 -the fruit, just as a man is suffocated if he were buried alive. SMEARED WITH VASELINE All you need to make a “gas store” is a well-built shed with thick walls, 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 tlie temperature of the fruit when it is first put into store, hut after this it needs only lie run for a few hours a (la\ r .

There are two commercial “gas stores,” at present, in Kent. A leading fruit-farmer lias transformed his toastliouse (one of those picturesque round brick kilns used for drying hops which are as much part of the friendly Kentish countryside as windmills arc 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 nails nearly airtight as it is possible for them to lie. They hold, in all, about J 2.000 bushels. NO WASTAGE Recently thousands- of baskets, each containing a bushel, wore taken out and loaded up for market, ‘they were all Bramley’s Seedlings, which is the most important variety of English apple, and comprises about three-quarters of the crop in the south-eastern fruit belt. “There is not more than 2 to 3 per cent, wastage,” the grower said. “This is something like half the usual amount.” . Tho correct concentration of carbon dioxide is about 10 per cent., and tbe temperature should be kept steady at 41(leg. or 42deg. F. During the winter it is often unnecessary to run the refrigerator. for days at a time. The exact proportion of C’o2 in Dio atmosphere in aiiy 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 tho spring. Two new -t gas stores” are likely to he put into operation next season. PROBLEMS STILL TO BE SOLVED 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 tho carbon dioxide. Gas stores, scientists say, should be placed in sheltered spots. New Zealand growers, however, have another problem; will “gas storage” work for Now Zealand varieties? So far, most of the apples commonly grown in Now Zealand and the other Dominions have not been tested. The British Department of Scientific and Industrial Research lias built, with money from the Empire Marketing Board, the largest experimental cold 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 are to be tackled. PEAR PROBLEMS They also hope to experiment with gas storage on other kinds of fruit. 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 be 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 those substances, condense them, and find out .just wliat gives a (-’ox’s Orange Pippin or a Jonathan its distinctive taste. Then, they hope, more will he known about whether gas storage can he used extensively to improve and cheapen storage of New Zealand and other Empire apples. • |