tailieunhanh - TEST DRIED FOOD

Centuries ago, man discovered that removing moisture from food helps to preserve it and that the easiest way to dot his is to expose the food to sun and wind. In this way, the North American Indians produce pemmican (dried meat ground into powder and make into cakes), the Scandinavians make stockfish and the Arabs dried dates and “apricot leather”. | TEST DRIED FOOD Centuries ago man discovered that removing moisture from food helps to preserve it and that the easiest way to dot his is to expose the food to sun and wind. In this way the North American Indians produce pemmican dried meat ground into powder and make into cakes the Scandinavians make stockfish and the Arabs dried dates and apricot leather . All food contain water cabbage and other leaf vegetables contain as much as 93 water potatoes and other vegetable 80 lean meat 75 and fish anything from 80 to 60 depending on how fatty it is. If this water is removed the activities of the bacteria which cause food go to bad is checked. Food is sun dried in Asia Minor Greece Spain and other Mediterranean countries and also in California South Africa and Australia. The methods used vary but in general the food is spread out on trays in drying yards in the hot sun. In order to prevent darkening pears peach apricots are exposed to the fumes of burning sulphur before drying. Plums for making prunes and certain variety of grapes for making raisins and currants are dripped in an alkaline solution in order to crack the skins of the foods slightly and remove their wax coating so increase the rate of drying. Nowadays most foods are dried mechanically. The conventional method of such dehydration is to put the food in chambers through which hot air is blown at temperature is about 110 Celsius at entry to about 43 C at exit. This is the usual method for drying such things as vegetables mint meat and fish. Liquid such as milk coffee tea soups and eggs may be dried by pouring them over the heated horizontal steel cylinder or by spraying them into a chamber through which a current of hot air passes. In the first case the dried material is scraped off the roller as the thin film which is then broken up into small those still relatively coarse-flakes. In the second process it falls to the bottom of the chamber as the fine powder. Where recognizable piece of meat and vegetables .