首页 | 主题 | 图库 | 问答 | 文摘 | 原创 | 百科

历史 | 地理 | 人物 | 艺术 | 体育 | 科学 | 音乐 | 电影 | 信息技术 | 世界遗产

 开放、中立,源自维基百科

Personal tools

Extract

From Wikipedia, the free encyclopedia

Jump to: navigation, search

An extract consists of a certain percentage of true essence, or its chemical imitation, in an alcoholic solution.

Note: The information in this article is primarily from an old reference.[1] Some of the names for chemical compounds and processes are a bit dated, and some of the techniques may have been superseded. However, the article is generally valid.

The aromatic principles of many spices, nuts, herbs, fruits, etc., and some flowers, are thus marketed, among the best known of true extracts being almond, cinnamon, cloves, ginger, lemon, nutmeg, orange, peppermint, pistachio, rose, spearmint, vanilla, violet, and wintergreen.

Contents

Extraction techniques

A majority of natural essences are obtained by extracting the essential oil from the blossoms, fruit, roots, etc., or the whole plants, through four techniques:

  • Expression when the oil is very plentiful and easily obtained, as in lemon peel.
  • Absorption is generally accomplished by steeping in alcohol, as vanilla beans.
  • Maceration is used to create smaller bits of the whole, as in making peppermint extract, etc.
  • Distillation is used with maceration, but in many cases, it requires expert chemical knowledge and the erection of costly stills.

The distinctive flavors of nearly all fruits, in the popular acceptance of the word, are very desirable adjuncts to many food preparations, but unfortunately there are only a few from which it is practicable to obtain a concentrated flavor extract of the necessary strength. Among those which lend themselves readily to the manufacture of "pure" extracts the most important are lemons, oranges and vanilla beans.


Chemical-created essence

A majority of other, concentrated fruit flavors, as banana, cherry, currant, peach, pineapple, raspberry and strawberry, are produced by chemical combinations of compound ethers, together with special oils, etc, the desired colors being generally obtained by the use of coal-tar dyes. Among the ethers most generally employed are Acetic and Butyric. The chief factors in the production of artificial banana and pineapple extract, and also important in the manufacture of strawberry extract, are amyl-acetate and amyl-butyrate, amyl alcohol being the principal constituent of that part of the alcohol obtained by the distillation of grain and potato starch, etc., which is popularly known in the US as fusel oil and in Europe, generally by the title of potato oil.

Artificial extracts do not, as a rule, possess the delicacy of the fruit flavor, but they get sufficiently close to it to be of real service and convenience when true essences are unobtainable.

See also

References

  1. ^ This article incorporates text from the public domain 1911 edition of The Grocer's Encyclopedia.



de:Drogenauszug et:Tõmmis (leotis) ja:エキス ru:Экстракт sq:Ekstrakti uk:Екстракт

AD Links