Dehydration (1943)

[Music] l today as of old American Indians make their crops stretch from Harvest to harvest using methods of food preservation that were discovered centuries ago today as then the principles are the same every housewife knows that precooking is a first step in food preservation because it destroys the enzymes that may cause undesirable flavor the housewife pre- Cooks by blanching with boiling water or steam the whole opies use their open ovens to pre-cook corn by roasting no Kett no containers no pressure cookers no modern paraphernalia of any kind hung in the open the sun's Rays dry them out and there you have it first pre-cooking then drying probably the oldest known method of food preservation but it's the basis of some of the most widely used of modern techniques the techniques of [Music] dehydration for many years the dehydration of foods has been the subject of extensive and continuous research the war stimulated This research because in war the bulk and weight of foods become tremendously important so science found new ways to save weight space containers Transportation ways to perfect these featherweight foods without destroying important food elements temperature control synchronization of mechanical handling and chemical reactions the elimination of bacterial development science redouble its efforts finding better ways to preserve precious vitamins and nutritional values science improved texture odor flavor and taste until as today you can hardly distinguish many of the newer dehydrated dishes from those cooked fresh new methods were developed to extend keeping qualities for indefinite periods and in any climate mechanical engineers have developed working models to test out proper air currents for drying the foods in the Laboratories countless experiments have been run to determine for example the exact brine solution that will make possible the quick removal of potato skins without destroying the important food values that lie directly under the skin peeling without waste of food or vitamins or [Music] minerals from forms such as this comes the milk to make dry skin milk solid without fat one of the most important dehydrated Foods in point of volume from Little crickles into quartz and gallons and from quarts and gallons into a regular Niagara of milk by the end of 1943 it was flowing into the dehydrating plants at the rate of over 639 million gallons a year enough to float a fleet of battleships it takes about 5 quarts of milk to make one pound of dry skin in other words the milk shrinks down to let less than 1/10th its original weight and 1/4 its original buk and that's one reason it is so valuable when shipping space is at a premium from the cows to the plant in a matter of just a few hours its handle will going to your table in fluid for is the number one requirement for any food that is to be dehydrated for the drying plants usually goes first to a nearby creamy to be separated the cream is made into [Music] butter the dehydration plant serves a number of creamies in its close vicinity from the tank trucks the skim milk is piped inside some plants handle as much as 400,000 lb of fluid milk a day as much as is used by a city the size of Denver inside the milk is put through condensers where heat removes about half of its water content then it's cooled again flowing over the coolers at about the consistency of cream the drying units in this plant are oblong [Music] cabinets inside the cabinets the milk is forced into fine spray around each spray is a continuous blast of hot air 350° transforming the milk into a fine powder almost instantly dropping through a hopper then into a moisture prooof Barrel ready for shipment milk with all its vitamins and proteins all except the fat and the water it's easy to see how you can get water out of milk because milk is liquid to begin with but vegetables well they are mostly water too take carrots about 90% moisture if that moisture is removed it's very apparent that the real food value will pack down into mighty little space and weight [Music] fresh from the fields to the drying plant in as short a time as possible that's one of the secrets of a good job of dehydration 300 tons of carrots a day can be handled at this plant every carrot handled individually topped and tipped and trimmed every defect removed [Applause] through a pressure washer and water conveyor up an elevator into a rotary pressure washer and a thorough rinse a peeling solution at exactly the right heat loosens the skins in about 2 and 1/2 minutes [Music] the Skins wash off in another rotary washer washed re-washed peeled and thoroughly clean the carrots go over an inspection belt they are diced by machines other vegetables may be diced or sliced or shredded spread out in thin even layers on trays the carrots go through a steam blanch quite a refinement in precooking over the old Indian method 8 minutes at 212° F sets the color and destroys any enzymes the trays are made of slats or wire mesh so that the heated air forced around them and the dryers will carry off the moisture into a primary drying tunnel as one car goes in another is pushed out Vans draw the heated air inside through louvers at the sides the carrots have lost all but about 25 or 30% of their moisture content now into a secondary tunnel where they're kept for 5 hours at a temperature of 163 de and at a relative humidity down to [Music] 12% then out of the secondary tunnel over 95% of their gure is gone remember they were about 90% water to begin with no need to ship all that water to Europe Africa or Asia what a saving in bulk and weight over a final inspection belt and into 5G cans each can gets slapped around to pack down the carrots until it holds 19 lb or what were four bushels in the [Music] field they'll keep in these cans indefinitely depending primarily on conditions of storage to make sure they'll keep this machine exhausts the air from the can and substitutes some inert gas such as carbon dioxide or nitrogen the cans are sealed and the carrots are ready for shipment and use [Music] the list of dehydrated Foods is long and is growing longer citrus juices are being made into [Music] powder cranberry sauce is turned into Flakes and [Music] powder there are other types of dryers too with the drum dryer the liquid this is tomato juice is spread on a heated revolving cylinder or drum formed into a sheet like tissue paper it is carried by a conveyor to a hammer Mill which reduces it to poter another type of rotary drum dryer is used for drying Meats cooked ground pork passes through the inside of the cylinder onto blasts of heated air after most of the moisture has been removed it is compressed in tin cans for shipment 10 sides of pork that's five big Hogs and in front you see the same amount of pork canned and boxed after it's been dehydrated conveyor dehydrators are a relatively new type these pre-cooked potatoes are riced onto the conveyor which carries them through the drying chamber this kind of dryer has the advantage of providing a continuous operation 1/3 of all the eggs produced in the United States in 1943 were dried they are broken by hand so each one can be inspected but after that the process is entirely mechanical and span and scrupulously clean this cone dryer has a 24-hour capacity of 4 tons of egg powder eggs are sprayed in Under Pressure a continuous blast of hot air surrounds the spray and dries it immediately the dried particles falling down the inside of the dryer exactly the same process as is used for drying milk the thick soft powder is scooped out at the bottom not a hand touches it each box holds the equivalent of one dozen eggs and no danger of broken shells they're good for cakes and custards bacon with eggs and omelets and they're good scrambled about the only order they won't fill is Sunnys side up the boxes are given a wax bath they'll shed water like a duck's back [Music] oh no this is not some inventor's nightmare it's a machine developed to help preserve dried foods under almost any conditions of transportation and climate on every box is the familiar Eagle under which millions of pounds of eggs were shipped under Len lease and what does it mean in cargo space one ship carries the equivalent of six shiploads of ordinary food less bul less wait and if you think that's not tremendously [Music] important mud rain shells danger but in war it's Mobility that counts and an Army moves on its stomach five cruxs of fresh food moreover would make a big Target but a little Jeep can carry the same amount dehydrated no matter on what Battlefront and no matter under what conditions our boys must have food and plenty of it but there's no room for bulky packages here yet what a bulk of food a small package can hold when it's dehydrated enough for a company [Music] 20 minutes from the time the reconstituted food is on the stove it's ready for the mess line that's the stuff that puts heart into a fighter cold and wet outside but Mighty warm and good inside [Music] yes sir dehydrated Foods helped win many a Battle and give hope and Life to countless of our Alles in war devastated countries dehydrated Foods by no means the least of the contributions of science to Victory and after the war well dehydrated Foods already have found their way into countless kitchens commercial food makers such as hotels restaurants bakeries candy manufacturers also use them in tremendous quantities the busy house wife if she chooses can bring home an entire family dinner in her handbag and without making it bulge [Music] either convenience and variety two things that are important in the kitchen no peeling or pairing no washing no waste in Mighty short order a dinner but a housewife a new choice in the matter of foods new possibilities in its form and use and convenience and for the American Farmer and the Food Industries new possibilities in production new markets fresh Horizons of opportunity that are always a part of the American way of life