| 翻訳と辞書 |
| Sugars in wine ： ウィキペディア英語版 |
Sugars in wine
The sugars in wine grapes are what make winemaking possible. During the process of fermentation, sugars are broken down and converted by yeast into alcohol (ethanol) and carbon dioxide. Grapes accumulate sugars as they grow on the grapevine through the translocation of sucrose molecules that are produced by photosynthesis from the leaves. During ripening the sucrose molecules are hydrolyzed (separated) by the enzyme invertase into glucose and fructose. By the time of harvest, between 15 and 25% of the grape will be composed of simple sugars. Both glucose and fructose are six-carbon sugars but three-, four-, five- and seven-carbon sugars are also present in the grape. Not all sugars are fermentable with sugars like the five-carbon arabinose, rhamnose and xylose still being present in the wine after fermentation. Very high sugar content will effectively kill the yeast once a certain (high) alcohol content is reached. For these reasons, no wine is ever fermented completely "dry" (meaning without any residual sugar). Sugar's role in dictating the final alcohol content of the wine (and such its resulting body and "mouth-feel") sometimes encourages winemakers to add sugar (usually sucrose) during winemaking in a process known as chaptalization solely in order to boost the alcohol content - chaptalization does not increase the ''sweetness'' of a wine.〔J. Robinson (ed) ''The Oxford Companion to Wine'' Third Edition pg 665-666 Oxford University Press 2006 ISBN 0-19-860990-6〕
== Glucose ==
Glucose, along with fructose, is one of the primary sugars found in wine grapes. In wine, glucose tastes less sweet than fructose. It is a six-carbon sugar molecule derived from the breakdown of sucrose. At the beginning of the ripening stage there is usually more glucose than fructose present in the grape (as much as five times more) but the rapid development of fructose shifts the ratio to where at harvest there are generally equal amounts. Grapes that are over ripe, such as some late harvest wines, may have more fructose than glucose. During fermentation, yeast cells break down and convert glucose first. The linking of glucose molecules with aglycone, in a process that creates glycosides, also plays a role in the resulting flavor of the wine due to their relation and interactions with phenolic compounds like anthocyanins and terpenoids.〔J. Robinson (ed) ''"The Oxford Companion to Wine"'' Third Edition pg 317 Oxford University Press 2006 ISBN 0-19-860990-6〕
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「Sugars in wine」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|