[原创]我的笔记--英文的，真的不知道对大家有没有用，只是一部分

Dream

[这个贴子最后由Dream在 2005/08/29 06:53am 第 1 次编辑]

[watermark]关于糖的Sugar中的 Sucrose蔗糖=
Carbohydrates’ types in food: sugars, dextrins, starches, celluloses, hemicelluloses, pectins and certain gums.
For simple carbohydrates (sugar), the different in arrangement of the elements result in differences in the solubility, sweetness, rates of fermentation by microorganisms, and other properties.
Amylose--- a straight chain fraction of starch.
Amylopectin--- a branched chain fraction.
Sugars that possess free aldehyde or ketone groups are known as reducing sugars. All monosaccharides are reducing sugars.
When 2 or more monosaccharides are linked together through their aldehyde or ketone groups, so that these reducing groups are not free, the sugar is nonreducing.eg,sucrose.
Reducing sugar are very reactive and can react with amino acid resulting in colour and flavour changes of foods.
Disaccharides:
     Sucrose (glucose葡萄糖 + fructose果糖) cane or beet sugar
     Maltose (glucose + glucose) malt
     Lactose (glucose + galactose) sugar in milk
In sucrose the glucose and fructose units are linked “head to head” via their reducing end groups to form sucrose. Sucrose is a non-reducing sugar. This linkage is unusual. More commonly monosaccharides are linked “head to tail” eg, C-1 to C-4 as between the glucose units of cellulose, maltose.
Glycosidic linkage between glucose and fructose is highly susceptible to hydrolysis by week acid.eg ,dilute vinegar (acetid acid) or by the emzyme invertase (found in some fruit and in the gut of humans)
        Invertase,sucrose
Sucrose -------------------------  D-glucose   +  D-fructose
        Or week acid             invert sugar
Hydrolysis results in an equimolar solution of glucose and fructose the product is know as invert sugar.
Sucrose is stable in alkaline conditions since it lacks a free carboxyl group.
Properties/Characteristics:
White crystalline substance/sweet, water soluble fermentable by microorganisms, hydrophilic, forms solutions of high osmolality. Acts as a preservative and humectant.
In a frazen solution of sucrose not all the water freeze to form ice. As ice is formed the concentration of sucrose in the remaining solution increases and the freezing point decreases. The viscosity of the solution increases and interactions between molecules are slow.
The liquid phase eventually forms a glass (solid)
Characteristics of concentracted mixes:
2 parts sucrose dissolved in 1 part water gives a solution of approx 67%. Greater concentrations can be achieved by rainsing the temperature of the water for dissolution.
The higher the concentration of the sucrose solution the higher the boiling point of such solutions.
When highly concentrated solution cool the sucrose may solidity in different forms
Eg, as an amorphous glass
   A semiplastic crystalline suspension in a saturated solution (fondant cream centres of shoes)
SUGARRelative Sweetness
Sucrose100
Fructose (levulose)140
Glucose (dextrose)70—80
Invert sugar>100
[color=#DC143C]这个是我自己做的笔记,真的不知道对大家有没有帮助,只是一小部分.因为都是英文,好多我都不知道怎么翻译,所以.........可以的话大家就看看吧[/watermark]

德氏兰

手抄？？书法应该很好

Dream

下面引用由德氏兰在 2005/08/28 06:49pm 发表的内容：
手抄？？书法应该很好

是手抄的，怎么了

德氏兰

我的外语忘记光了，只记得高中有一学期连续抄过几片课文

insecteater

All monosaccharides are reducing sugars.eg,maltose。。。。。。。
？？？？？seems wrong, maltose is disacharide, not mono.

Dream

下面引用由insecteater在 2005/08/28 08:36pm 发表的内容：
All monosaccharides are reducing sugars.eg,maltose。。。。。。。
？？？？？seems wrong, maltose is disacharide, not mono.

should be right~ let me check it

Dream

yep,im sorry ,it';s wrong .If we start with a-D-glucose and join two molecules together, we get maltose.iv already said Maltose (glucose + glucose),hehe~
im sorry about that~thx a lot~

菩提树

thanks