Page:Popular Science Monthly Volume 90.djvu/716

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��Popular Science Monthly

��So, to offset any incompleteness of dry- ing, it was found advisable in other lands to cook, the vegetables first, thus arresting by so much any tendency to spoil. Briefly, that method consists in parboiling the vegetables and then drying them suffi- ciently to prevent subsequent deterioration or fermentation. The latter step is accomplished with heat.

To prepare the great majority of vegetables dried in this way for table use, it is necessary to cook them. The dried farm products, already parboiled, thus must be re- cooked.

This is the main fault with the old method. Twice cooked vegetables are generally some- what flat.

��How America At- tacked the Problem

���Such was the status of vegetable preservation through drying when Waldron Williams and his associates took up the work in this country. Farm products were being dried abroad. But they were not as palatable as fresh vegetables. The task was to conserve them and at the same time, keep their food value and taste un- altered. This these men have succeeded in doing.

The American process as it now stands consists in utilizing heated air currents at relatively low temperatures, which serve to draw out, absorb and carry off the moisture in sliced vegetables while leaving them otherwise absolutely unimpaired.

The vegetables are first cut up but not parboiled or in any other way treated. Then they are subjected to the new moisture-extracting process.

The volume of the air currents and their temperature can now be controlled to a nicety, as a result of long and exhaustive investigation. The time required to dry farm products depends wholly upon the vegetables dealt with. The period of treat- ment ranges from two hours to about five; this can be readily appreciated if the

��The bottoms of the frames used in the ovens are of screening to permit the passage of air

��varying moisture content of the different vegetables is taken into consideration.

For instance, fresh beets contain 87 per cent of water; cabbages, 91.5 per cent; onions, 87 per cent; potatoes, 78 per cent; and tomatoes as much as 94.3 per cent. The greater the volume of water present, the longer the drying operation must be maintained in order to reduce the mois- ture content to the desiredminimum and at the same time dry the vegetables uniformly.

How well the new vegetable drying sys- tem works out, in the matter of retain- ing intact the natural flavor of fresh farm products, is evi- denced by the testi- mony of a New York housekeeper, a friend of one of the scientists.

Merely to satisfy her curiosity, a pack- age of dried spinach was sent to her. When next she saw her acquaint- ance she declared that that spinach

��The dried vegetables in the barrel repre- sent about fifteen hundred pounds or thirty barrels of the turnips, carrots and onions shown below

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