Food colours are the any substance, pigment or dye, that helps to gives colour when it is added to food atom. They come in many forms consisting of gels, powders, pastes and liquids, . The acceptance of a food depends to a real extent upon its more attractive colour.
The basic colour of any raw foods is due to its pigments naturally present in it. Sometimes, artificial colour is additional throughout the preparation and process of food to create them additional attractive.
(A) Natural food colours
The natural colours (pigments) in vegetables and fruits will be classified on the idea of chemical structure as carotenoids (yellow-orange), chlorophylls (green).
The other examples are flavonoids and anthocyanins (red, blue and purple) and anthoxanthins (cream yellow).The following pigments are present, one by one or together, in plant-based foods.
These green colored, fat-soluble pigments, concerned in chemical process, are present in several plants specially in leafed vegetables like cabbage and lettuce.
So there area unit 2 varieties of pigment, a-pigment and b-pigment, that occur in plants within the quantitative relation of 3:1. They are the porphyrins, a vital cluster of biological pigments which has hemoprotein.
There’s always some deterioration of chlorophylls on storage, regardless of the method coluring methodology used.
Carotenoids are fat-soluble, orange-yellow pigments that are gift in several vegetables and fruits like mango, carrot, pumpkin and orange. The primary pigment isolated was from carrot and, therefore,was named carotene. Its concentration in an exceedingly vegetable is indicated by the intensity of the colour.
The most cosmopolitan carotenoids area unit xanthophyl, violaxanthin, and neoxanthin that found in inexperienced leaves. Carotene and carotenoid additionally occur wide however in tiny quantities.
Some pigments predominate in bound plants like carotenoid in tomato, capsanthin in red pepper and bixin in annatto. Carotenoids are present in most green leafy vegetables beside chlorophyll however their color is g by the green of pigment.
Carotenoids are extracted from annatto, saffron, paprika, tomato, etc. And used as natural food colourants. Extracts of carrot, butter fat and vegetable oil contains ß-carotene the precursor of vitamin a and therefore show vitamin a activity.
These are the red, blue and purple water-soluble compounds occurring within the cell sap of some fruits and vegetables, e.g., colored grapes, cheery, apple, red cabbage, and in most flowers.
Anthocyanins are glycosides that on chemical reaction yield colored aglycones called anthocyanidins, that are phenylbenzopyran derivatives, and sugars.
The sugar moities are aldohexose, arabinose, xylose,galactose, rhamnose, etc. An oversized range of anthocyanidins ar familiar of that six ar commonly present in foods. These ar pelargonidin, cyanidin, delphinidin, peonidin, petunidin and malvidin.
At low pH, the color of anthocyanins is an intense red, that changes through orange and red to blue or purple because the hydrogen ion concentration worth rises. Sulphite or sulfur dioxide chop-chop bleaches the colour of anthocyanins.
Removal of sulphite by boiling and natural action leads to the regeneration of anthocyanins.
They’re soluble, polyphenolic substances, similar in structure to anthocyanins, that additionally occur as glycosides, and include the sub-groups of flavones, flavonols, flavanones, chalcones, aurones.
Flavonoids could also be the only pigments in such vegetables as potato, cauliflower and yel low-skinned onion.
The flavonoids most ordinarily found within the nature are the flavonols, kaempferol, quercetin and myricetin present in wide amounts in tea. Less common are flavones like apigenin, luteolin and tricetin.
The opposite sub-groups occur to a restricted extent. Flavones and anthoxanthins ar accountable for the yellow-white or creamy white colour of potato and cauliflower. Flavanones occur primarily in citrus plants and might be useful as artificial sweeteners.
These are the creamy yellow, creamy white or yellow . water soluble compounds occurring within the cell saps of some fruits and vegetables, e.g., potato, cauliflower.
Anthoxanthins are glycosides that on boiling with dilute acid yield one or 2 molecules of monosaccharides and a flavone or by-product like flavonal, flavanonal, or isoflavone.
Tannins are colourless or yellow substances that turn brown once fruits and vegetables containing them, e.g., brinjal, gourd, apple, are cut and exposed to air.
So tannins are liable for catalyst browning and additionally for the astringency of foods. Tannins are a complex mixture of compound polyphenols additionally Know tannin or gallotannic acid, and derivatives of flavones.
They’re divided into 2 major groups
(i) reaction tannins, e.g., acid (gallotannins) (ii) ellagic acid (ellagitannins).
7. Quinones and Xanthones
An oversized variety of pigments found within the cell sap of flowering plants, fungi, microorganism and protoctist are derivatives of anthraqui none, vitamin K and compound and place color from straw to virtually black.
Anthraquinone derivatives are the biggest cluster of such pigments, followed by those of vitamin K and compound.Xanthones are a group of yellow pigments. One well-known member is mangiferin, that happens as a glycoside in mangoes.
Betalains area unit a group of red and yellow pigments found in red beet (Beta vulgaris) and, to some extent, in succulent fruits, pokeberries and variety of flowers (Bougainvillea). They check the anthocyanins and flavonoids in structure however in contrast to them and ontain chemical element.
Betalains are stable within the pH vary 4-6 however are degradation by thermal process as in canning. change the food might not continually return from plant and animal pigments.
It can be thanks to browning reactions that will be enzymatic or nonenzymatic. This side of colouring has been Pointing in an exceedingly separate chapter entitled ‘Browning Reactions’.
Colouring matters, whether or not isolated from a natural supply or synthesized, are allowable to be adscititious to any article of food.
Dehydration of beet powder, carrot oil and juices of fruits, e.g., strawberries and cherries, that impart a pink color to ice-cream also are approved as natural colour additive.
(B) Artificial food colours
Only pigments from natural sources were out there and used for colouring food until the approaching of the primary coal tar dye in 1857.
Thereafter an oversized variety of dyes were synthesized and a few were used as food colourants.
There are three types of artificial food colours
1. Primary Food colours
Primary Food colours are water soluble, and exhibit coloring power once dissolved. These food colours have high utilitarian worth & immensely used dyes in food, pharmaceutical, cosmetic & numerous different industries.
These primary food colours are in accordance with the international food quality standards.
a. Quinoline Yellow
A bright yellow dye with green shade.
These food colours are method by creating use of high grade ingredients keeping in mind the standard norms.
Carmoisine, a red to maroon shade in applications, is loving for its usage in cold beverages, ice cream and sweat meat.
Tartrazine, an artificial yellowness dye, used big variety of foods together with desserts and candies, soft drinks, condiments, and breakfast cereals.
Erythrosine provides a pink to carmine pink shade in applications, is often utilized in candies, popsicles and cake-decorating gels.
2. Blended Food colours
Blended colours are obtains from compounding totally different primary and secondary colours either severally or with each other.
The resultant colours are distinctive in visual property and supply a distinct feel to products.
a. Egg Yellow blended colours
Used for Food,Tablets, Syrups & Beverages.
b. Dark Chocolate blended colours
Used for Food Flavorings, dairy farm products, shop things, Cosmetics and Soft Drinks. It’s an important coloring ingredient across the planet.
c. Apple green blended colours
Used for esters,hydrocarbon solvent, wax, candles, and soap quite coloring.
3. Lake Food colours
Lake colours are used wherever dyes aren’t appropriate due to their solubility in water.
The colors are bright, consistent and helpful in industries like prescribed drugs, cosmetics, inks, plastic food containers etc.
a. Lake Quinoline Yellow
Quinoline Yellow Lake, a artificial additive is popularly used across varied industries and is accessible at cheap costs.
It’s on the market in Powder type and is equally soluble in variety of liquids.
b. Lake Tartrazine
Lake Tartrazine is employed each in business food production and in domestic change of state.
It’s an energetic ingredient of varied food products like custards, cereals, ice creams, beverages and confectionery things.
c. Lake Erythrosine
A cherry pink / red artificial pitch dye used as pigments for surface coating, capsules, dry snacks in food packaging material.
The above mentioned food colours used in food processing industries. I hope you may get all the information concerning about what are food colours, when reading my article. After this, if you’ve got any doubt then i will be able to help you tell me the comments section.