GASSING TOMATOES

Hawera Star, Volume L, 7 February 1931, Page 9

GASSING TOMATOES

A N address on artificial colouring and ripening of fruit was given by Dr. W. Pugh, of the University of Cape Town, at a meeting of the Cape Section of the Institute of Chemistry of Great Britain, and Ireland, says the Cape Times.” Dr. Pugh said that artificial treatment of fruit had been of great importance in America . for many yeans ■d. with the proximity of the coming fruit season in South. Africa, the new method of treatment should be of considerable interest and! value to fruit growers aud dealers. He had demonstrated to a leading local fruit dealer that it was possible to bring to full red colour green Transvall tomatoes in half the time required by air storage. There was, he said, no objection to hastening the colouring process of mature fruit. There were many types of fruit which were quite ripe, so far as the taste was concerned, long before '■i'v acquired) a marketable colour. If these were allowed to ripen on the vine, they became too soft to withstand bruising during transport. Tomatoes, for example, were picked green and l acquired a pleasing colour during two or three weeks’ storage. Cutting down thiß time would relieve considerable space for other purposes. During transport a very considerable nroportion of the fruit was spoiled. This spoilage could; be considerably reduced if the fruit were picked when firm and hard and then artificially ripened. It was now claimed that the new ethylene treatment could, to some extent, act as foster mother, stimulating the normal ripening processes which \vere ; checked on picking. 13<?s t prices were paid at- tlie oe<£innino- of the season and the new procesT would enable the progressive grower to get his. crop on the market first. Tt also made it possible for the crop to be harvested at the first sign of frost ancl marketed subsequently, according to the demand.

How to Gain That Rich Red

In America, a. method of treatment that liad been in use for many years consisted of treating fruit with the fumes from burning oil stoves. The method, however was never, really successful, and in 1923 investigations were undertaken to determine the constituent of the oil fumes responsible for the effect. This was ultimately traced to minute traces of ethylene, and_ it was amazing what/ low concontrat/ions of gas would do. One part of ethylene in I. (100,000 parts of air was as efficientas the old stove process. Higher concentrations had a better effect, but it was not necessary to use more than one part .per 1000 of air. Th e temperature was important and in all cases should be of between 65 and 85 degrees Fahrenheit. Two charges of gas- should be given each day and ventilation was recommended between each charge. . , Almost every kind of fruit had been 'oiind amenable to this treatment. With proper care there was no danger in the use of ethylene at these low concentrations. Ethylene gas, he said, -as supnlied in stedl cylinders of about 350 cubic, feet. It was not obtainable • the Union, but must be imported. The cylinder of gas costs about £3. but. in addition, a charge of roughly £6 was made for the cylinder, which, however, was returnable. Dr. Pugh said this was a process which might well be more widely used in this country. It should be possible now for tropical fruit from the north and from Natal to lie more available in other parts of the country: A>s a warning. however, he said the process was <incn to abuse. It would be a pity if the process, in its infancy, canto to be used by irresponsible persons for the, purpose of giving immature fruit the •'unression of ripeness, thereby bringing discredit to a process which, when ‘no perl y applied, could he of greatvalue.