首页
登录
职称英语
Centuries ago, man discovered that removing moisture from food helps to pres
Centuries ago, man discovered that removing moisture from food helps to pres
游客
2024-02-28
48
管理
问题
Centuries ago, man discovered that removing moisture from food helps to preserve it, and that the easiest way to do this is to expose the food to sun and wind. In this way the North American Indians produce pemmican (dried meat ground into powder and made into cakes), the Scandinavians make stock fish and the Arabs dried dates (枣) and "apricot leather" (杏干).
Fruit 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 fruit is spread out on trays in drying yards in the hot sun. In order to prevent darkening, pears, peaches and apricots are exposed to the fumes of burning sulphur (硫磺) before drying. Plums (李子), for making prunes (梅干), and certain varieties of grapes for making raisins (葡萄干) and small dried grape cakes, are dipped in a salt solution in order to crack the skins of the fruit slightly and remove their wax coating, thus increasing the rate of drying.
Nowadays most foods are dried mechanically. The conventional method of such dehydration (脱水) is to put food in chambers through which hot air is blown at temperatures of about 110℃ at entry to about 43℃ at exit. This is the usual method for drying such things as vegetables, cut meat, and fish.
Liquids such as milk, coffee, tea, soups and eggs may be dried by pouring them over a heated horizontal steel roller or by spraying them into a chamber through which a current of hot air passes. In the first case, the dried material is removed off the roller as a thin film which is then broken up into small, though still relatively coarse thin pieces. In the second process it falls to the bottom of the chamber as fine powder. Where recognizable pieces of meat and vegetables are added, as in soup, the ingredients are dried separately and then mixed. [br] How long has tile open-air method of drying food been known by man?____________
选项
答案
For hundreds of years/centuries.
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3490547.html
相关试题推荐
Inthelatenineteenthandearlytwentiethcenturies,oneofthemostclearl
Inthelatenineteenthandearlytwentiethcenturies,oneofthemostclearl
Inthelatenineteenthandearlytwentiethcenturies,oneofthemostclearl
Inthelatenineteenthandearlytwentiethcenturies,oneofthemostclearl
Inthelatenineteenthandearlytwentiethcenturies,oneofthemostclearl
Inthelatenineteenthandearlytwentiethcenturies,oneofthemostclearl
Inthelatenineteenthandearlytwentiethcenturies,oneofthemostclearl
Inthelatenineteenthandearlytwentiethcenturies,oneofthemostclearl
Inthelatenineteenthandearlytwentiethcenturies,oneofthemostclearl
Inthelatenineteenthandearlytwentiethcenturies,oneofthemostclearl
随机试题
Hewasfrightenedby______lightning.A、boltofB、apieceofC、aflashofD、aA
秘书在做督查工作时,必要时可以直接处理问题,代替下属机关和部门工作。()
患者30岁,因右侧下后牙反复肿痛就诊。查:右下5无龋,面磨损可见牙本质暴露,探无
A.灵敏度高B.特异性强C.敏感性高和特异性强D.用于检测同一标本中的两种抗原E
可以用于预防和治疗各种A型流感病毒的药物是A.阿昔洛韦B.阿糖胞苷C.齐多夫定D
各种运输方式内外部的各个方面的构成和联系,就是( )。 A.运输系统
(2011年)当企业既提供竞争性业务又提供垄断性业务并实施交叉补贴时,则()。A
将财政支出分为经济建设费、国防费、社会文教费、行政管理费和其他支出,是按财政支出
为了保证住宅质量,对高层住宅及地基、结构复杂的()应当实行监理。A.多层住宅
建筑节能分部工程质量验收合格应符合下列()规定A.建筑节能各分项工程应全部
最新回复
(
0
)