2017年10月28日 星期六

蟲膠 Shellac E904 胭脂蟲紅 Carmine E120



 Source:  Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services, Bugwood.org

香口膠成分含有蟲膠 (Shellac)，食物標籤編號為E904。主要用來作為食物的上光劑，使他們看上去更有光澤更吸引。 蟲膠由膠蟲壓碎提煉而成。膠蟲通常在樹上棲身，並分泌出蠟質蟲膠把自己固定在樹上。
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紅絲絨蛋糕原來都有蟲！

紅色食品多數包含染色成分胭脂蟲紅(Carmine)，食物標籤編號為E120，是由胭脂蟲壓碎過濾而取出的紅色色素。 参考: http://www.gotrip.hk/weekend_lifestyle/lifestyle/恐怖食物成份-香口膠-蟲膠/

Source:  http://www.alibaba.com/product-detail/Carmine-E120-Food-Color_118558128/showimage.html

Wikipedia:

 To prepare carmine, the powdered scale insect bodies are boiled in an ammonia or sodium carbonate solution, the insoluble matter is removed by filtering, and alum is added to the clear salt solution of carminic acid to precipitate the red aluminium salt, called "carmine lake" or "crimson lake" (the lake here deriving from the word lac, referring to a resinous secretion). Purity of color is ensured by the absence of iron. Stannous chloride, citric acid, borax, or gelatin may be added to regulate the formation of the precipitate. For shades of purple, lime is added to the alum; thus, the traditional crimson color is guaranteed not only by carminic acid but also by choice of its chelating metal salt ion.[6]
Carmine may be prepared from cochineal,[7] by boiling dried insects in water to extract the carminic acid and then treating the clear solution with alum. Other common substances such as cream of tartar, stannous chloride, or potassium hydrogen oxalate can also be used to effect the precipitation, but aluminum is needed for the color. Use of these chemicals causes the coloring and animal matters present in the liquid to be precipitated to give a lake pigment. Aluminum from the alum gives the traditional crimson color to carminic acid precipitates, which are called "carmine lakes" or "crimson lakes". This color is degraded by the presence of iron salts. Addition of lime (calcium) can give carminic acid lakes a purple cast.[6]
Other methods for the production of carmine dye are in use, in which egg white, fish glue, or gelatin is sometimes added before the precipitation.
The quality of carmine is affected by the temperature and the degree of illumination during its preparation, sunlight being requisite for the production of a brilliant hue. It also differs according to the amount of alumina present in it. It is sometimes adulterated with cinnabar, starch and other materials; from these, the carmine can be separated by dissolving it in ammonia. Good carmine should crumble readily between the fingers when dry.

Properties and uses

A reflectance spectroscopy study of one commercially available dye based on carminic acid found that it reflects mostly red light with wavelengths longer than about 603 nm,[8] which provides its saturated red color.
Carmine can be used as a staining agent in histology, as a Best's carmine to stain glycogen, mucicarmine to stain acidic mucopolysaccharides, and carmalum to stain cell nuclei. In these applications, it is applied together with a mordant, usually an Al(III) salt.
Carmine was used in dyeing textiles and in painting since antiquity.[9] It is not very stable in oil paint, and its use ceased after new and better red pigments became available. Jacopo Tintoretto used carmine in several of his paintings, including Portrait of Vincenzo Morosini[10] and Christ Washing the Feet of the Disciples.[11]

Allergy

Carmine is used as a food dye in many different products such as juices, ice cream, yogurt, and candy, and as a dye in cosmetic products such as eyeshadow and lipstick. Although principally a red dye, it is found in many foods that are shades of red, pink, and purple. As a food dye it has been known to cause severe allergic reactions and anaphylactic shock in some people.[12][13]

Source: Wikipedia


A cluster of Dactylopius coccus females growing in Barlovento, La Palma, Canary Islands


Source: Wikipedia

Zapotec nests on Opuntia ficus-indica host cacti

Cochineal, Carmine, Carminic acid (E120)


Carmine is the name of the colour pigment obtained from the insect Dactylopius coccus (old name Coccus cacti), that lives on cacti from the genus Opuntia. The insect is native to tropical South and Central America and produces the pigment as a deterrent against other insects. The pigment can be obtained from the body and eggs of the insect. It is still used as an organic ant-repellent.
Source: http://www.food-info.net/uk/colour/cochineal.htm


Source: http://www.food-info.net/uk/colour/cochineal.htm

 Cochineal is one of the few natural and water-soluble colorants that resist degradation with time. It is the most light- and heat-stable and oxidation-resistant of all the natural colorants and is even more stable than some synthetic food colours.
Cochineal it is neither toxic nor known to be carcinogenic. However, the dye can induce an anaphylactic-shock reaction in a small number of people, due to impurities in the preparation, not due to the carminic acid.
History
Cochineal was already used as a colour by the Aztec and Maya peoples of Central and North America . Cochineal was a commodity of much value, even comparable to gold. Cities send bags of cochineal to the capital Tenochtitlán as a yearly contribute to the emperor. The Spanish conquerors of Central America saw the value of the dye, which produced a much better colour than the dyes used in Europe at the time. The dye, which at the time was mainly used in cosmetics and textiles and to a lesser extend in foods, became very popular in Europe. Roman Catholic Cardinals robes were coloured with cochineal, as were the jackets of the British military. Cochineal was a highly prized product and was regularly traded on the London and Amsterdam Commodity Exchanges. As its origins were not known to most Europeans, the American colonists bought their cochineal from Europe, instead directly from Mexico ...
In the 19th century the insects were imported and grown on a large scale on the Canary Islands and the Mexican monopoly came to an end. In 1868, the Canary Islands exported six million pounds of cochineal, equivalent to 420.000.000.000 insects....
In addition as a dye for textiles, cochineal became widely used as a food colouring. Cakes, cookies, beverages, jam, jelly, ice cream, sausages, pies, dried fish, yogurt, cider, maraschino cherries and tomato products were brightened with it as were chewing gum, pills and cough drops. Cosmetic rouge was developed with cochineal as the main ingredient. Cochineal is still widely used in cosmetics.
The demand for cochineal fell sharply with the appearance on the market of alizarin crimson and many other artificial (food and textile) dyes discovered in Europe in the middle of the 19th century. Trade in cochineal almost totally disappeared in the course of the 20th century, but in recent years it has become commercially valuable again as many producers (and consumers) prefer natural colours over synthetic colours. However, most consumers are unaware that the ‘natural colouring E120' refers to a dye that is derived from an insect. It is thus not suitable for vegetarians and is banned by some religions.
Production
The insects are killed by immersion in hot water (after which they are dried) or by exposure to sunlight, steam, or the heat of an oven. Each method produces a different colour which results in the varied appearance of commercial cochineal. The insects must be dried to about 30 percent of their original body weight before they can be stored without decaying. It takes about 155,000 insects to make one kilogram of cochineal.
There are two principal forms of cochineal dye: cochineal extract (E120(ii) ) is a colouring made from the raw dried and pulverised bodies of insects with around 20% carminic acid; and carmine ( E120(i) ) a more purified colouring made from cochineal.
Polish cochineal
Polish cochineal is another dye, which was widely used until the mid 19th century as a textile dye. It was not used as a food dye. Polish cochineal is also derived from an insect, the Margarodes polonicus, found in Eastern Europe and parts of Asia.
Cochineal Red
This is the name of an azo dye, E124, which bears no resemblance with cochineal, but produces a similar colour, hence the (confusing) name.
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