2. • Color is a measure of quality and nutrient content of foods.
• The objective of adding color is to give appealing.
• Demand for natural color is increasing worldwide - therapeutic and medicinal
properties and Toxicity of synthetic colors.
• Among all the natural dyes, plant-based pigments have medicinal values so they are
mostly preferred
Natural colorants are those derived from naturally occurring sources such as plants,
insects, animals and minerals.
Indian Agricultural Research Institute, New Delhi
3.
4. 1.Tetrapyrrole compounds:-
> Chlorophylls , Hemes, and Bilins
2. Isoprenoid derivatives:-
> Carotenoids
3. Benzopyran derivatives:-
> Anthocyanins and
flavonoids
4. Others :-
> Melanoidins,
caramels
Natural Food Colorants
Indian Agricultural Research Institute, New Delhi
5. Tetrapyrrole compounds:-
• The basic unit from which the Tetrapyrrole pigments are derived is
pyrrole.
• This is relatively small group of pigment that contribute the
greatest range of colors and as well as most abundant globally
Pyrrole - C4H5N
Indian Agricultural Research Institute, New Delhi
6. Chlorophylls
Chlorophyll, Formula - C55H72O5N4Mg
• The chlorophylls are green pigments responsible for the color of leafy
vegetables and some fruits.
• In green leaves, the chlorophyll is broken down during senescence and the
green color tends to disappear.
• In many fruits, chlorophyll is present in the unripe state and gradually
disappears as the yellow and red carotenoids take over during ripening.
7. • In plants, chlorophyll is isolated in the chloroplastids and these are microscopic
particles consisting of even smaller units, called grana.
• The chlorophylls are Tetrapyrrole pigments in which the porphyrin ring is in the
dihydro form and the central metal atom is magnesium. There are two
chlorophylls, a and b, which occur together in a ratio of about 3:1,
• Chlorophyll b differs from chlorophyll a in the methyl group on carbon 3 is
replaced with an aldehyde group.
8. Heme Pigments
• It also possesses four pyrrole rings.
• However, it differs from chlorophyll in that the central
magnesium atom has been replaced by a iron atom.
• Heme is most abundant throughout the animal kingdom
where it tends to associate with proteins forming complexes,
such as the myoglobin in the muscle and the hemoglobin in
the blood.
• It functions as an oxygen carrier within the animal bodies.
• When the central iron atom is oxidized, as in oxygenated
blood, the complex is bright red in color.
• Upon heating, however, the oxygen atom which is loosely
bound will be lost, giving rise to a brownish color,
characteristic of cooked meat.
Indian Agricultural Research Institute, New Delhi
10. Carotenoids
• Carotenoids also called as carotenes, are a group of lipid-soluble hydrocarbons
and there oxygenated derivatives called xanthophylls.
• The carotenoids take their name from the major pigments of carrot (Daucus
carota). The color is the result of the presence of a system of conjugated
double bonds.
• They are found most in yellow and red fruits and roots .
• The most widely distributed are the carotenoids found in green leaves , lutein ,
violaxanthin and neoxanthin. Others found in small quantities but occurring
widely are beta-carotein and zeaxanthin.
• Other pigments like lycopene in tomato , capsanthin in red pepper and bixin in
annatto , predominate in certain plants.
• Carotenoid consist of eight isoprenoid units joined in such a manner that the
arrangement of isoprene units is reversed in the center of the molecule
Indian Agricultural Research Institute, New Delhi
11. • Carotenoids exist in nature in the free state in plant tissues as a crystalline or a
amorphous solids , or in solution in lipid media. They also occurs as esters or in
combination with sugars and proteins.
• The alternate double bond in their structure are responsible for the color of
carotenoids.
Lycopene
Lutein
Indian Agricultural Research Institute, New Delhi
Isoprenoid unit
13. • beta-carotein is the precursor of vitamin A ; it yields two molecules of vit A
by a cleavage at the center of the molecule.
• It under goes oxidation by enzymes and nonenzymatically.
• The pigment may autoxidize by reaction with atmospheric oxygen.
• In the presence of USFA , lox brings oxidative degradation of carotene.
• Carotenes can also change color by undergoing isomerization from trans to
cis configuration and the change in color is promoted by the presence of
acid and with temperature.
• Natural source of carotenes – annatto , saffron , paprika , tomatoes ,carrot ,
palm oil etc.
14. Provitamin A Value of Some Fruits and Vegetables
Product IU/100g
Carrots 10,000
Spinach 13,000
Broccoli 3,500
Apricots 2,000
16. Anthocyanins
• The anthocyanin pigments are present in the sap of plant cells; they take
the form of glycosides and are responsible for the red, blue, and violet
colors of many fruits and vegetables.
• When sugars moiety are removed by hydrolyses the aglucone remains and
is called anthocyanidin.
• The anthocyanins are highly colored, and their names are derived from
those of flowers.
• Substitution of hydroxyl and methoxyl groups influences the color of the
anthocyanins.
• Increase in the number of hydroxyl groups tends to deepen the color to a
more bluish shade
Indian Agricultural Research Institute, New Delhi
17. • Increase in the number of methoxyl groups increases redness.
• The anthocyanins can occur in different forms. In solution, there is an
equilibrium between the colored cation R+ or oxonium salt and the colorless
pseudo base ROH, which is dependent on ph.
R+ H2O ROH + H+
• Anthocyanidin are highly colored in strongly acid medium.
• About 16 anthocyanidin have been identified in natural products, but only
the following six of these occur frequently and in many different products:
pelargonidin, cyanidin, delphinidin, peonidin, malvidin, and petunidin.
Indian Agricultural Research Institute, New Delhi
18. Indian Agricultural Research Institute, New Delhi
• All anthocyanins are derivatives of the basic FLAVYLIUM cation structure.
• Anthocyanins are polyphenols containing OH groups in 3,5 and 7 carbon atom.
• The presence of sugar moiety in the anthocyanin molecule is responsible for their
high solublity in water.
19. Structures of some important anthocyanin's
Delphinidin Cyanidin
Peonidin
Indian Agricultural Research Institute, New Delhi
21. • These are also polyphenolic substances with structure similar to
anthocyanins and also occur as glycosides.
• Flavonoids differ from anthocyanins in having a carbonyl group in position 4 .
Flavonoids
Flavonol
Ex. Quercetin
Flavanone
Ex. Naringin
Apigenin
22. • The major group of flavonoids found in nature is the Flavonol group
consisting of Kaempferol , Quercetin and Myricetin. Ex . Tea
• Flavonones found mainly in citrus plants and they can be used as synthetic
sweeteners .
• A compound synthesized from naringin has a sweetness nearly 2000 times
that of sucrose.
23. Tannins Tanic acid or Gallotanic acid
• Tannins are polyphenolic compounds present in many fruits and
they are important as color compounds and also for their effect on
taste as a factor in astringency.
Tannins can be divided into two classes
1. Hydrolyzable tannins
2. Nonhydrolyzable or condensed tannins
The tannins are characterized by the presence of a large number of
hydroxyl groups, which provide the ability to form reversible bonds with other
macromolecules, polysaccharides, and proteins, as well as other substances such as
alkaloids.
This bond formation may occur during the development of the fruit or during the
mechanical damage that takes place during processing.
The appearance of tannins ranges from colorless to yellow or brown.
Tannins contribute to the astringency of foods and also enzymatic browning
reactions. Ex- Aonla , Persimon
25. • Hydrolyzable tannins are composed of phenolic acids and sugars that can be
broken down by acid, alkaline, or enzymic hydrolysis. They are polyesters
based on gallic acid and/or hexahydroxydiphenic acid .
• Gallotannins release gallic acid on hydrolysis, and ellagitannins produce
ellagic acid.
• Ellagic acid is the lactone form of hexahydroxydiphenic acid, which is the
compound originally present in the tannin.
• Nonhydrolyzable or condensed tannins are also named proanthocyanidins.
• Gallnut contains 50-70 % tannin.
Indian Agricultural Research Institute, New Delhi
26. Betalains
• Centrospermae, the plant order to which beet belongs, is the only group of plants known to
produce betalains.
• Betalains can be divided into two classes of pigments, namely, betacyanins and betaxanthin.
• Betacyanin refers to the red pigment that may be extracted from the red beetroot Beta vulgaris
and the major component in this class of pigment is betanin .
• Betaxanthin, refers to the yellow pigment obtained from the yellow beet root Beta vulgaris
var. lutea and the major components found in this class of pigment are vulgaxanthine.
• The color of betalains is due to their resonating structure .
If R or R1 does not extend resonance , the
compound is yellow and is known as betazanthin and If R or R1 extends resonance , the compound
is red and called betacyanin.
The color of betanin depends on pH; between four and five it is bright bluish-red, becoming blue-violet as the pH
increases. Once the pH reaches alkaline levels betanin degrades by hydrolysis, resulting in a yellow-brown color..
27. • Due to the high level of Betalains found in beetroot, the plant is deemed a
valuable source of food colorant.
• Commercial production of Betalains involves a counter current liquid/solid
extraction process. This is followed by an aerobic fermentation, generally with
Candida utilis, to remove the large amount of sugar present.
Ex . Beetroot , cactus fruits , pokeberries and bougainvillea.
Basic structure of betalin
28. Chalcone
• The chalcones are water-soluble pigments extracted from petals of safflower
(Carthamas tinctorius). Red carthamin, safflower yellow A, and safflower
yellow B are the three chalcones that have been isolated and identified in
the safflower extract.
• At the moment, chalcone does not have many applications in the food
industry. Due to such limitations, applications of chalcone so far are
restricted to foodstuffs such as noodles, yogurts, and fruit juices (e.g.,
pineapple juice).
29. Annatto
• Annatto is an orange-yellow colored carotenoid derived from seeds of Bixa
orellana,
• It is estimated that every year about 7000 tons of the annatto seed are used for
the production ofthe food colorantworldwide,
• Annattoisbasicallyamixtureof twocompounds, bixinandnorbixin.
Bixin, which is the mono-methyl ester of a dicarboxylic carotenoid, is the major component in
the mixture . It is also a fat-soluble compound which is extracted from annatto seeds with edible
oil. The fatsoluble bixin is also used in conjunction with other food colorants to produce various
shades of color. For example, it may be used with paprika oleoresin to give a redder shade in
processed cheese.
Norbixin Alkaline hydrolysis of bixin yields the free acid norbixin, which is also the minor
component found in annatto. The water-soluble norbixin may also be extracted from the annatto
seeds using aqueous alkali. Applications of norbixin include smoked fish, cheese, baked goods,
meat products (e.g.,frankfurtersausages),snackfoods, andsugarconfectionery.
Indian Agricultural Research Institute, New Delhi
31. Saffron
• Saffron is one of the earliest food additives used by man.
• It is a water soluble extract obtained from the stigma of the
flowers of Crocus sativus.
• This plant is the major source for the commercial production of
the pigment.
• The same pigment may also be obtained from the flowers of
C. albifloris, C. lutens, Cedrela toona, Nyctasthes arbortristes,
Verbascum phlomoides, and Gardenia jasminoides
Indian Agricultural Research Institute, New Delhi
32.
33. Chalcone
The chalcones are water-soluble pigments extracted from petals of
safflower (Carthamas tinctorius).
applications of chalcone so far are restricted to foodstuffs such as
noodles, yogurts, and fruit juices (e.g., pineapple juice).
Red carthamin, safflor yellow A, and safflower yellow B are the three
chalcones that have been isolated and identified in the safflower
extract.
Indian Agricultural Research Institute, New Delhi
34. Pigments from Animal and Insect Sources
• Cochinealisananthraquinonewhichhasbeenusedfor
centuriesasaredcolorant,mainlyfordyeingtextilesandthis
redpigmentsobtainedfromfemalecoccidinsect
• Cochineal pigment is carminic acid from the female Dactylopius
coccus aparasite ofthe cactus plants .
• Armenian red—obtained from the coccid insect Porphyrophyra
hameli, which is found growing on the lower stems and roots of
grasses.
• Lac dyes (laccaic acid ) from lac insect - Laccifera lacca, which can be
found in the trees Schleichera oleosa, Zizyphus mauretania, and
Buteamonosperma inthe Indian subcontinent, China,andMalaysia.
It has beenusedtraditionally bythe Chinese to coloragar.
Indian Agricultural Research Institute, New Delhi
35.
36. Miscellaneous Plant Pigments
• CurcuminisextractedfromTurmeric
Rhizome
• TheTurmericextractactuallycomprises
threepigments:curcumin,
demethoxycurcumin,and
bisdemethoxycurcumin.
• Themajorpigmentcurcumin,whichis
insolubleinwater.However,ithasbeen
reportedthatawater-solublecomplexmay
beobtainedbyreactionthepigmentwith
metalssuchaszincchloride.
Indian Agricultural Research Institute, New Delhi
40. PERMITTED NATURAL COLOUR
Approved in the EU and USFDA
• Chlorophyll
• Beta-carotene,
• Beta-apo-8' carotenal,
• Canthaxanthin
• lutein
• Paprika extract – Capsanthin ,
Capsorubin
• Lycopene
• Caramel
• Annatto, Bixin, Norbixin
• Saffron
• Anthocyanin
• Curcumin or turmeric
41.
42. Food Permitted colorant Maximum level
Butter Carotene Quantum satis
Margarine Curcumin , carotene ,
Annatto , bixin , Norbixin
10 mg / kg
Sage-derby cheese Chlorophyll , chlorophillin Quantum satis
Ripening orange colored
cheese
Carotene Quantum satis
Non flavored processed
cheese
Annatto , bixin , Norbixin 15 mg / kg
Red leicestr cheese Cochineal , caramine 125 mg/kg
Vegetable soaked in vinegar
or brine
Carotene
Betann
Quantum satis
Quantum satis is a Latin term , meaning the amount which is needed.
43. Food Permitted colorant Maximum level
Extruded , Puffed break fast
cereals
Carotene
Annato
Paprika extract
Quantum satis
25 mg / kg
Quantum satis
Break fast cereals flavored
with fruit
Cochineal , caramine 200 mg / kg
Jam , Jelly , Marmalade Curcumin
Chlorophyll , chlorophillin
Carotene
Paprika extract
Quantum satis
Jam , Jelly , Marmalade Cochineal , caramine 100 mg / kg
Minced meat with a veg /
cereal content min 4 %
Cochineal , caramine 100 mg / kg
Potato flakes Curcumin Quantum satis
Source book - Coloring of Food, Drugs, and Cosmetics
By Gisbert Otterstätter – 1995
44. Source book - Coloring of Food, Drugs, and Cosmetics
By Gisbert Otterstätter – 1995
46. ANNATTO
• In commercial processing, annatto coloring is extracted from the
reddish pericarp which surrounds the seeds Bixa orellene L.
• Historically, it has been used as coloring in many cheeses (e.g., Cheddar,
Gloucester, Red Leicester), cheese products (e.g. American cheese, Velveeta),
and dairy products (e.g. butter, margarine).
• Annatto can also be used to color a number of non-dairy foods such as
rice, custard powder, baked goods, seasonings, processed potatoes, snack
foods, breakfast cereals and smoked fish.
Source – Google Wikipedia
47. Betalains
• The most common uses of betalins are in coloring ice
cream and powdered soft drink beverages; other uses are In hot processed
candies, it can be used if added at the final part of the processing.
• Betalin is also used in tomato soups . Betalin does not cause allergy when
used as a coloring agent
Source – Google Wikipedia
48. Paprika
• It is principally used to season and color rices, stews(gravy),
and soups and in the preparation of sausages as an
ingredient mixed with meats and other spices.
• "The Hungarian varieties are more robust and considered
superior.
Source – Google Wikipedia
49. Turmeric
• Turmeric is sometimes used to impart a rich, custard-like yellow color.
• It is used in canned beverages, baked products, dairy products, ice cream,
yogurt, yellow cakes, orange juice, biscuits, popcorn color, cereals, sauces etc.
• It is a significant ingredient in most commercial curry powders.
• In combination with annatto (E160b), Turmeric has been used to color
cheeses, yogurt, dry mixes, salads, butter and margarine.
• Turmeric is also used to give a yellow color to some prepared mustards,
canned chicken and other foods (often as a much cheaper replacement for
saffron).
Source – Google Wikipedia
50. E-number for currently allowed color additives
Approved in the EU and Approved in the US
E-number Name(s) Colour
E100 Curcumin Yellow-orange
E101 Riboflavin Yellow-orange
E120
Cochineal, Carminic acid
Carmine
Crimson
E160b Annatto, bixin, norbixin Orange
E160c
Paprika oleoresin, Capsanthin,
capsorubin
Red
E160d Lycopene Bright to deep red
E160e Beta-apo-8'-carotenal (C 30) Orange-red to yellow
E162 Beetroot Red Red
E163 Anthocyanins pH dependent
E164 Saffron Orange-red
E numbers are the codes for substances that can be used as food additives . Safety
assessment and approval are the responsibility of the European Food Safety Authority.
51. ADVANTAGES OF NATURAL COLORS
• Eco-friendly , less polluting and recycled after use.
• Natural dyes are less toxic.
• less health hazardous.
• Non-carcinogenic and non-poisonous and prevent chronic diseases such as prostrate cancer.
• In addition to this, they are harmonizing colours, gentle, soft and subtle, and create a restful
effect.
• Most of them are water-soluble (anthocyanins), which facilitates their incorporation into
aqueous food systems.
• They attribute to food-both for aesthetic value and for quality judgment and also they tend
to yield potential positive health effects, as they possess potent antioxidant and improve
visual acuity properties.
• They have also been observed to possess antineoplastic, radiation-protective, vasotonic,
vasoprotective, anti-inflammtory, chemo- and hepatoprotective activities.
• Low-fat content‘ is the objective for many new or improved food formulations,
replacing fats with thickeners or other food additives; ·
• Increased consumer preferences for organic food; ·
• Variety and internationalisation of food colour and flavours.
52. Disadvantages
• Tedious extraction procedures of colouring component from the raw
material.
• low colour value and longer time make the cost of dyeing with natural dyes
considerably higher than synthetic dyes.
• Some of the natural dyes are fugitive and need a mordant for enhancement
of their fastness properties while some of the metallic mordents are
hazardous.
• Difficulty in the collection of plants and species availability.
• Lack of standardization, lack of availability of precise technical knowledge of
extracting and dyeing technique.
• The use of these colorants in food products may also face some problems
due to their instability during processing due to their sensitivity to
temperature, oxygen, light and pH.
• They can also be decolourised or degraded during storage.