An extract (essence) is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol, oil or water. Extracts may be sold as tinctures, absolutes or in powder form. The aromatic principles of many spices, nuts, herbs, fruits, etc., and some flowers, are marketed as extracts, among the best known of true extracts being almond, cinnamon, cloves, ginger, lemon, nutmeg, orange, peppermint, pistachio, rose, spearmint, vanilla, violet, rum, and wintergreen. Most natural essences are obtained by extracting the essential oil from the feedstock, such as blossoms, fruit, and roots, or from intact plants through multiple techniques and methods: Expression (juicing, pressing) involves physical extraction material from feedstock, used when the oil is plentiful and easily obtained from materials such as citrus peels, olives, and grapes. Absorption (steeping, decoction). Extraction is done by soaking material in a solvent, as used for vanilla beans or tea leaves. Maceration, as used to soften and degrade material without heat, normally using oils, such as for peppermint extract and wine making. Distillation or separation process, creating a higher concentration of the extract by heating material to a specific boiling point, then collecting this and condensing the extract, leaving the unwanted material behind, as used for lavender extract. The distinctive flavors of nearly all fruits are desirable adjuncts to many food preparations, but only a few are practical sources of sufficiently concentrated flavor extract, such as from lemons, oranges, and vanilla beans. The majority of concentrated fruit flavors, such as banana, cherry, peach, pineapple, raspberry, and strawberry, are produced by combining a variety of esters with special oils. Suitable coloring is generally obtained by the use of dyes. Among the esters most generally employed are ethyl acetate and ethyl butyrate. The chief factors in the production of artificial banana, pineapple, and strawberry extract are amyl acetate and amyl butyrate.

À propos de ce résultat
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.

Graph Chatbot

Chattez avec Graph Search

Posez n’importe quelle question sur les cours, conférences, exercices, recherches, actualités, etc. de l’EPFL ou essayez les exemples de questions ci-dessous.

AVERTISSEMENT : Le chatbot Graph n'est pas programmé pour fournir des réponses explicites ou catégoriques à vos questions. Il transforme plutôt vos questions en demandes API qui sont distribuées aux différents services informatiques officiellement administrés par l'EPFL. Son but est uniquement de collecter et de recommander des références pertinentes à des contenus que vous pouvez explorer pour vous aider à répondre à vos questions.