Other concentrated milk products are evaporated or condensed milks. These do serve as direct substitutes for the original, simply by the restoration of the original amount of water content. Large shipments of these products are going forward regularly from Canada and the United States to Great Britain. The next logical step in the process is the complete dehydration into powdered form. This has been an expanding industry in recent years. Milk in powdered form occupies only about onequarter of the space taken by evaporated milk and approximately oneeleventh of the volume of the original fluid milk. Experiments are now under way in Canada to make further economies. Dried milk is usually packed in tins or small containers, in loose powder form. Half a ton of milk was recently sent from Ontario to Great Britain in the form of solid blocks, packed in large cartons. If these experiments are successful further important economies in shipping space will result. The drying of eggs has until last year only been incidentally carried on in this continent, and industries using dried eggs have depended upon China for their supply. The cutting off of this source and spectacular demand for military use and overseas shipment have resulted in a tremendous increase in output. In 1939 the United States eggdrying industry prepared only 10 million pounds of dried egg products. By 1941 this had been increased to 45 million pounds, and it has been estimated that output in 1942 will reach 150 million pounds. Some fear has been expressed that the present expansion in the industry will have severe repercussions, when conditions of normal supply and demand are restored after the war. It should be noted, however, that production of this year's quota will involve operation of the plants twentyfour hours a day throughout the year and that the industry can go back to a peacetime operation with an eighthour day and a fourmonth season. On this basis output would be only 17 million pounds per annum, or slightly larger than prewar consumption in the United States. Egg drying in Canada has also begun to expand. During 1941 we delivered 15 million dozen eggs to Great Britain. These eggs were shipped in the shell, and owing to shipping delays their condition upon arrival was not always satisfactory. Egg deliveries to Great Britain in 1942 are expected to reach 45 million dozen eggs, and since February 7th all of these have been shipped in the dried form. Although the drying capacity in Canada has been sharply increased it is not yet capable of handling all the eggs available at the period of peak production and the surplus eggs are being packed for future processing. While there has been a substantial growth in the processing of milk and eggs by dehydration, the industry which has received the greatest publicity and aroused most public interest is the dehydration of vegetables. During the World War of 191418 a substantial quantity of dehydrated vegetables was prepared and shipped to Europe, primarily for the use of United States armed forces. These were not popular in general they tasted like anything but vegetables, and the kindest description of their flavour was that it resembled hay. The industry died away at the end of the war almost as rapidly as it had risen. The last few years, however, have seen a revival of interest and of operation in the dehydrated vegetable industry. This revival has, curiously enough, been based upon discoveries made in research for a rival, the quickfrozen food industry. In the earlier days of the latter industry the same problem of haylike flavour arose. Research indicated that this was due to activity of enzymesthose curious biological catalysts present in all living matter without which the chemical changes necessary for its existence could not take place. It was discovered by pioneers in the frozen food industry that a preheating or blanching process immediately prior to freezing prevented activity of the enzymes during the period when the food remained frozen. As a result of the lack of chemical change the flavour remained unaffected. It is thus against the background of this research rather than as a result of immediate war demands that the dehydrated vegetable industry has so far had its development. For a number of years the industry in the United States has been slowly growing, and a survey conducted last year by the United States Department of Commerce indicated that fifteen commercial plants produced slightly less than 5 million pounds of dehydrated vegetables in 1940. Nearly twothirds of the output was in the form of powders to be used for seasoning, including such highly flavoured vegetables as onions, celery and red peppers. The remainder of the output was either in the form of mixed vegetables which, combined with animal protein and flavourings, make up the now familiar packaged soups. There has also been, however, a relatively substantial volume of production for dehydration and use in the form of the original vegetable. One company in fact has specialised in the production of potato shreds which permit the preparation of mashed potatoes in five minutes. The greater part of the output was purchased by hotels, restaurants and other large organisations where convenience in use was a major factor. The direct sale to individual consumers was only in the preliminary stages. The increased demand for food products in the United States, both for the armed forces and for shipment abroad under leaselend, has aroused an intense interest in the industry. The United States Department of Agriculture announced at the beginning of June a programme of technical assistance and priorities on materials for food processors desirous of converting their plants. Compared with the fifteen plants producing 5,000,000 pounds in 1940, there are now reported to be 113 companies operating dehydration plants, with an aggregate annual production of 125,000,000 pounds. Potential demand may be measured by the fact that if dehydrated potatoes were served to the men in the United States army only once a week it would require 7 million pounds of finished product per annum of this vegetable alone. The types of dehydrated vegetables most in demand are potatoes, onions, cabbages, carrots, beets and tomatoes. The important factor in all these products is quality. Dehydration is not a process for getting rid of secondgrade products. One successful operator has found that green peas for dehydration should be of approximately the same quality as those used for quickfreezing, and must be better than the average quality of peas canned. If the product is to be restored to anything like palatable flavour and texture the flavour must be there to begin with. During recent months the Canadian Government has been actively encouraging experimental work in the dehydration of vegetables.
British Food Journal – Emerald Publishing
Published: Apr 1, 1943