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Message de mar4gaux posté le 15-11-2013 à 19:51:05 (S | E | F)
Bonjour,
nous avons un exposé en anglais pour mardi.
Pouvez-vous le corriger s'il vous plaît?
Merci d'avance pour votre généreuse aide. Bon week -end
We will present you the coloring substance for dye and food.
For a start, a coloring substance is a kind of substance which is able to fix, on a support, to give it a color. A dye si a sort of coloring substance; if you dye something, such as cloth, you change its color by soaking it in a special liquid. The presence of the coloring substances in the life si very important. They are used in many ownerships like food, clothes, hair... These coloring substances for dye and food are the result of the additive synthesis.
In a first part, we will speak about the coloring substances for food and, in a second part, about dyes.
I: The coloring substances for food.
In cookery, the coloring substances are used to give colors at the foodstuffs or just to restore their original colors. They are the result of natural products which are gringed or of substances which are not poisonous to the system.
There are 3 kind of coloring substances (3 families):
Naturals (Ex: the green of the chlorophilly)
Artificials (with out natural equivalents)
Of synthesis (with out « identicals nature »)
These coloring substances are part of the modern chemistery's district so they are tested by different organizations like FD&C in the USA.
The German chemist, Otto Witt (19° century) explained why an organic molecule si colored and, in this way, si able to act as coloring substances; doing reactions with coloring objects and hydrogene, he notes that there si decoloration. He deduced that every coloring molecules contain atoms' groups unsaturated (with one or more double connections). This group of atoms si called « Chromophore ».
There are several colors:
Blue/green: a mixing of blue and yellow. There si just one green coloring substance: E 140 (natural chlorophilly) used for chewing-gum. The blue E 133 si synthesic but no toxic. It si used in Curaçao.
Brown/black: all the E 150 are based with camarel. And the black E 153 with natural coal.
Yellow: E 100, some are not allowed in France because they are toxic.
Red: They are natural and with out danger like the Cochenille.
II: Dyes.
[A venir]
To conclude, the coloring substances for dye and food are very similar. They have the 3 families in common (natural, synthetic, artificial). Moreover their colors are the same.
In a near future, we may develope lasting technics as the preserving of food and lasting coloration of clothes.
Merci encore
-------------------
Modifié par lucile83 le 15-11-2013 21:33
Message de mar4gaux posté le 15-11-2013 à 19:51:05 (S | E | F)
Bonjour,
nous avons un exposé en anglais pour mardi.
Pouvez-vous le corriger s'il vous plaît?
Merci d'avance pour votre généreuse aide. Bon week -end
We will present you the coloring substance for dye and food.
For a start, a coloring substance is a kind of substance which is able to fix, on a support, to give it a color. A dye si a sort of coloring substance; if you dye something, such as cloth, you change its color by soaking it in a special liquid. The presence of the coloring substances in the life si very important. They are used in many ownerships like food, clothes, hair... These coloring substances for dye and food are the result of the additive synthesis.
In a first part, we will speak about the coloring substances for food and, in a second part, about dyes.
I: The coloring substances for food.
In cookery, the coloring substances are used to give colors at the foodstuffs or just to restore their original colors. They are the result of natural products which are gringed or of substances which are not poisonous to the system.
There are 3 kind of coloring substances (3 families):
Naturals (Ex: the green of the chlorophilly)
Artificials (with out natural equivalents)
Of synthesis (with out « identicals nature »)
These coloring substances are part of the modern chemistery's district so they are tested by different organizations like FD&C in the USA.
The German chemist, Otto Witt (19° century) explained why an organic molecule si colored and, in this way, si able to act as coloring substances; doing reactions with coloring objects and hydrogene, he notes that there si decoloration. He deduced that every coloring molecules contain atoms' groups unsaturated (with one or more double connections). This group of atoms si called « Chromophore ».
There are several colors:
Blue/green: a mixing of blue and yellow. There si just one green coloring substance: E 140 (natural chlorophilly) used for chewing-gum. The blue E 133 si synthesic but no toxic. It si used in Curaçao.
Brown/black: all the E 150 are based with camarel. And the black E 153 with natural coal.
Yellow: E 100, some are not allowed in France because they are toxic.
Red: They are natural and with out danger like the Cochenille.
II: Dyes.
[A venir]
To conclude, the coloring substances for dye and food are very similar. They have the 3 families in common (natural, synthetic, artificial). Moreover their colors are the same.
In a near future, we may develope lasting technics as the preserving of food and lasting coloration of clothes.
Merci encore
-------------------
Modifié par lucile83 le 15-11-2013 21:33
Réponse: Exposé euro/ couleurs de lucile83, postée le 17-11-2013 à 22:52:09 (S | E)
Anyone? Réponse: Exposé euro/ couleurs de bluestar, postée le 18-11-2013 à 13:17:11 (S | E)
Bonjour..
Quelqu'un avec les connaissances techniques pourrait faire un meilleur travail que moi ici
Color =
Colour=
Vous avez écrit "is" deux fois dans la deuxième ligne, puis vous changez de "si" - qui pensez-vous est la bonne?
Numbers d'additif sont généralement écrits sans espace: E153 pas E 153
We will present you (prep.manquante) the coloring substance (pluriel) for dye and food.
For a start, a coloring substance is a kind of substance which is able to fix, on a support, to give it a color.(a reformuler) A dye si a sort of coloring substance; if you dye something, such as cloth, you change its color by soaking it in a special liquid. The presence of the coloring substances in
In
I: The coloring substances for food.
In cookery, the coloring substances are used to give colors at the foodstuffs or just to restore their original colors. They are the result of natural products which are
gringed or of substances which are not poisonous to the system. There are 3 kind of coloring substances (3 families):
Naturals (Ex: the green of the chlorophilly (verifier orthographe))
Artificials (with out un mot - natural equivalents)
Of synthesis (adjectif pas nom ici) (with out « identicals nature »)
These coloring substances are part of
The German chemist, Otto Witt (19° century) explained why an organic molecule si colored and, in this way, si able to act as coloring substances (singulier); doing reactions with coloring objects and hydrogene, he notes that there si decoloration. He deduced that every coloring molecules (singulier) contain atoms' groups unsaturated (with one or more double connections). This group of atoms si called « Chromophore ».
There are several colors:
Blue/green: a mixing of blue and yellow. There si just one green coloring substance: E 140 (natural chlorophilly orth.) used for chewing-gum. The blue E 133 si synthesic(orth.) but not toxic. It si used in Curaçao.
Brown/black: all the E 150 are based with camarel (verifier orth.). And the black E 153 with natural coal.
Yellow: E 100, some are not allowed in France because they are toxic.
Red: They are natural and with out danger like the Cochenille. (orth.)II: Dyes.
[A venir]
To conclude, the coloring substances for dye and food are very similar. They have the 3 families in common (natural, synthetic, artificial). Moreover their colors are the same.
In
Réponse: Exposé euro/ couleurs de mar4gaux, postée le 18-11-2013 à 18:45:55 (S | E)
Merci beaucoup de votre aide j'ai la deuxieme partie si vous avez le temps :
Originally ( in Egypt) , the dyes are natural ( plant : crimson : natural indigo dye for " blue jeans ."
When chemistry began to make progress from the mid-nineteenth century , natural dyes of plant origin ( madder , indigo, pastel, weld ) or animal ( cochineal , kermes ) were gradually replaced by synthetic dyes.
Since the late nineteenth century, many families of dyes have been developed : azo dyes , dyes quinacriores ... etc. . There are no less than 8000 synthetic dyes of different chemical nature . Today , most of the dyes are artificial .
The cotton clothes in bright colors should not be washed at temperature in excess of 60-70 ° to avoid the release part of the dyes fixed on the fibers, since they react in alkaline environment. How the dyes cling to the fibers ?
Metallic salts (It's a metal combined with oher non-metallic elements for instance sodium chromate) being differentiated in the water, the metal is in the form of ions*, more specifically cations ( positively charged ions). However, the fibers have electron rich atoms (based on oxygen atoms in particular ) . They therefore have a strong affinity for these metal ions just waiting to fill their electron deficit .
*Reminder: an atom can gain or lose one or more electrons, it then becomes a anion (negative) or cation (positive).
There are three techniques of dyeing:
- A dye having a chlorine atom is reacted with an OH-group (oxygen and hydrogen) of a cellulosic fiber (plants), forming a covalent chemical bond.
The fiber of the dye is effected by the presence of an intermediate: « mordant ». The intermediary is a metal cation catching the dye on the fiber.
The dye is solubilized by converting into the salt by the action of sodium hydroxide. Then the molecule is regenerated by oxygen.
Réponse: Exposé euro/ couleurs de bluestar, postée le 18-11-2013 à 19:03:25 (S | E)
Bonsoir..
Originally ( in Egypt) ,
When chemistry began to make progress from the mid-nineteenth century , natural dyes of plant origin ( madder , indigo, pastel, weld ) or animal ( cochineal , kermes ) were gradually replaced by synthetic dyes.
Since the late nineteenth century, many families of dyes have been developed : azo dyes , dyes quinacriores ... etc. . There are no less ("fewer" serait mieux) than 8000 synthetic dyes of different chemical nature . Today , most of the dyes are artificial .
The cotton clothes in bright colors should not be washed at temperature in excess of 60-70 ° to avoid the release (gerondif -ing) part of the dyes fixed on the fibers, since they react in alkaline environment. How (auxiliare manquant) the dyes cling to the fibers ?
Metallic salts (
*Reminder: an atom can gain or lose one or more electrons, it then becomes a anion (negative) or cation (positive).
There are three techniques of dyeing:
- A dye having a chlorine atom is reacted (utiliser actif pas passif voix) with an OH-group (oxygen and hydrogen) of a cellulosic fiber (plants), forming a covalent chemical bond.
The fiber of the dye is effected (affected?) by the presence of an intermediate: « mordant ». The intermediary is a metal cation catching the dye on the fiber.
The dye is solubilized by converting into the salt by the action of sodium hydroxide. Then the molecule is regenerated by oxygen.
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