Brief about Pigments and their sources

1. PIGMENTS
D.SRENUJA
15FT1D7804

2. • Color-To denote the human eye’s perception of colored
materials, part of the electromagnetic spectrum visible to the
human eye and generally regarded as lying between 400 - 700
nm i.e. red, blue, or green.
• Together with flavor and texture, color plays an important
role in food acceptability.
• Color is mainly a matter of transmission of light for clear
liquid foods, such as oils and beverages.
• Color may provide an indication of chemical changes in a
food, such as browning and caramelization.

3. • Pigment: A pigment is a material that
changes the color of as the result of
wavelength-selective absorption.
• They are the natural substances in cells and
tissues of plants and animals.
• Dyes are any substances that lend to color to
materials and are water soluble.
• Dyes are food grade , certified by U.S. F.D.A.
• Lakes are dyes extended on a substratum
and they are oil dispersible.

4. Plant Pigments: Normal constituents of
cells or tissues,that impart color. It has other
properties, i.e. energy receptor, carriers of O2,
protects against radiation.
1. Chlorophylls
2. Carotenoids
3. Flavonoids
4. Anthocyanins
5. Tannins
6. Betalains
7. Quinones
8. Xanthones

5. Chlorophylls:
 They are major light
harvesting pigments in
green plants, algae and
photosynthetic bacteria.
 They are Mg complexes
derived from Porphin.

6. α
β
γ
δ
α
β
γ
δ
Phorbin
 Pyrrole C-atoms on the periphery of the Porphin structure are
numbered 1 to 8.
 Carbon atoms of the bridging carbons are designated as α,β,γ
and δ.
 Substituted porphins are named as porphyrins, it is macro
cyclic tetra pyrrole pigment in which the pyrrole rings are
formed by the methane bridges , double bonds forms closed
conjugated loop..
 Phorbin is considered to be the nucleus of all chlorophyll and
is formed by the addition of a fifth iso-cyclic ring to Porphin.
 Porphin is fully
unsaturated
macrocyclic
structure that
contains 4 pyrrole
rings linked by
single bridging
carbons.

7. • There are 6 different types of Chlorophyll pigment that have
been identified by famous chemists including Richard
Willstätter, HansFischer, Robert Burns Woodward and Ian
Fleming. Their structures are based on a chlorin ring at the
center of which is a magnesium ion.
• The structure can have different side chains depending on the
type of Chlorophyll.
A. Chlorophyll a:
 Chlorophyll a is the most widely occurring and universal type
of Chlorophyll.
 It is found in plants, algae and many other aquatic organisms.
 Chlorophyll a is molecular structure consists of a chlorin ring
with Mg center.
 It absorbs light from red, blue and violet wavelengths and gets
its color by reflecting green.

8. B. Chlorophyll b:
It is a type of Chlorophyll that is mostly found in
plants.
It aids the process of photosynthesis, by
absorbing light energy.
 And primarily it absorbs blue light.
The pigment itself is yellow in color.
Similar to Chlorophyll a , Chlorophyll b's
molecular structure has a 4-ions Nitrogen ring
with Mg center, with side chains hydrocarbon
trail.

9. Structures of chlorophyll a and b
Chemical Group: Tetrapyrroles

10. C . Chlorophyll c1:
 Chlorophyll c1 works in conjunction with Chlorophyll a to
absorb light and aid photosynthesis.
 This type of Chlorophyll has a brownish or golden color
and is found mostly in marine algae.
 The molecular structure of Chlorophyll c1consists of a
Chlorin ring but does not have a tail.
D . Chlorophyll c2:
 Similar to Chlorophyll c1, Chlorophyll c2 is mostly found
in marine and freshwater algae.
 Its molecular structure has a 4 ion Nitrogen ring and Mg
center but does not have a tail.

11. Chlorophyll C1 and C2

12. E. Chlorophyll d:
• Identified comparatively recently 1996, Chlorophyll d is a type
of Chlorophyll that absorbs light which is in the extreme red
end of the light spectrum.
• The natural occurrence of Chlorophyll d is found only in
Acaryochloris marina, a type of Cyanobacteria.
F. Chlorophyll f:
• Chlorophyll f absorbs infrared light, from most extreme end of
red spectrum.
• Chlorophyll f occurrence in nature is very less,except i.e.,found
in Cyanobacteria.
• Chlorophyll f exact function in the process of photosynthesis is
also uncertain.

13.  Chlorophyll is registered as a food additive (colorant), and its E
number is E140.
 Chefs use chlorophyll to color a variety of foods and beverages
green, such as pasta products.
 Chlorophyll is not soluble in water, and it is first mixed with a
small quantity of vegetable oil to obtain the desired solution.

14. Chemistry:
 They are associated with carotenoids ,lipids
and lipo-proteins.
 Weak linkages(non-covalent bonds) exist
between these molecules.
 The bonds are easily broken, hence
chlorophylls can be extracted by macerating
plant tissue in organic solvents.

15. C . Carotenoids:
Occurrence:
 Carotenoids are lipid-soluble, yellow–orange–red
pigments found in the chloroplasts and chromoplasts
in plants and animals.
 Animals cannot synthesize carotenoids, so their
presence is due to dietary intake.
 Carotenoids are the most complex class of natural
food colorants with around 750 different structures
identified.
 Carotenoids can be divided into carotenes containing
only carbon and hydrogen.

16. Chemical Group : Tetraterpenoids
 Carotenoids has two structural
groups , they are hydrocarbons
carotenes and oxygenated
xanthophyll.
 This xanthophyll consists
hydroxyl , epoxy , aldehyde and
ketone groups.
 The basic carotenoid structural
backbone consists of isoprene
units linked by covalently in
either a head-to-tail or a tail-to-
tail fashion.

17. Lycopene:
 Being a precursor in the biosynthesis of β-carotene, lycopene
can be expected to be found in plants.
 The best-known sources of lycopene are tomatoes, watermelon,
guava, and pink grapefruit.
 In tomato oleoresin also contains appreciable amounts of β-
carotene, phytoene, and phytofluene
Lutein:
 Lutein is also a very common carotenoid. The name is derived
from the Latin word for yellow.
 Lutein is made from Aztec marigold also contains some
zeaxanthin (typically less than 10 %).
 Containing only 10 conjugated double bonds, lutein is more
yellowish-green.

18. Chemistry:
• Their color is masked by chlorophyll in photosynthetic
tissues, but in late stages of plant development these pigments
contribute to the bright colors of many flowers and fruits and
the carrot root.
• A good source of plant carotenes is oil palm (Elaeis
guineensis) fruits, the mesocarp of which contains an oil rich
in carotenes.

19. Flavonoids:
 Flavonoids or bioflavonoids (from the Latin word flavus
meaning yellow, their color in nature) are a class of plant
secondary metabolites.
 Over 5000 naturally occurring flavonoids have been
characterized from various plants.
 They have been classified according to their chemical
structure, and are usually subdivided into the following
subgroups
Sub-groups:
 Anthoxanthins (Flavone & Flavonol )
 Flavanones
 Flavanonols
 Flavans
 Anthocyanidins

20. Structure:
 Chemically, they have the general structure of a 15carbon
skeleton, which consists of two phenyl rings (A and B) and
heterocyclic ring (C).
 This carbon structure can be abbreviated C6C3C6.
 The chemical group in flavonoids is O-heterocyclic
compounds.
 The three cycle or heterocycles in the flavonoid backbone are
ring A, B and C. Ring A usually shows a phloroglucinol
substitution pattern.

21. Chemistry:
 Flavonoids are the most important plant pigments for
flower coloration, producing yellow or red/blue
pigmentation in petals designed to attract pollinator
animals.
 Foods with a high flavonoid content include parsley , onions
, blueberries and other berries, black tea, green tea and
oolong tea, bananas, all citrus fruits, Ginkgo biloba, red
wine,cauliflower,etc.,.

23. Anthocyanins :
 Anthocyanins (also anthocyans; from Greek:(Anthos)-
flower +(kyanos) = blue).
 They belong to a parent class of molecules called flavonoids
as ,they are odorless and nearly flavorless, contributing to
taste as a moderately astringent sensation.
Occurrence:
 Anthocyanins occur in all tissues of higher plants, mostly in
flowers and fruits but also in leaves, stems, and roots.
 In these parts, they are found predominantly in outer cell
layers such as the epidermis and peripheral mesophyll cells
and also cell vacuole.

24.  No fewer than 109 tons of anthocyanins are produced in
nature per year.
 According to 2003, more than 400 anthocyanins had been
reported while more recent literature (2006), puts the number
at more than 550 different anthocyanins.
 Not all land plants contain anthocyanin; in the
Caryophyllales (including cactus, beets, and amaranth), they
are replaced by betalains.
 Anthocyanins and carotenoids contribute distinctive
pigmentation to blood oranges.

25. Structure:
 The basic structure of anthocyanins is 2-phenylbenzopyrylium
of flavylium salt.
 They differ in the number of polyhydroxy and/or polymethoxy
derivatives of the salt.
 An anthocyanin pigment is composed of an aglycone esterified
to 1 or more sugars with O-heterocyclic compunds (chemical
group).
 When the sugar moiety of an anthocyanin is hydrolyzed ,the
aglycone (non-sugar hydrolysis product)is called
Anthocyanidin.
 The anthocyanins are subdivided into the
sugar-free anthocyanidin a glycones
and the anthocyanin glycosides.

26. Chemistry:
 They are water soluble pigments that may appear red, purple,
or blue depending on the pH.
 Roughly 2% of all hydrocarbons fixed in photosynthesis are
converted into flavonoids and their derivatives such as the
anthocyanins.
 Plants rich in anthocyanins are such as berries ,blackcurrant,
cherry, eggplant peel, black rice, grapes, red cabbage,peaches
and apples.
 Anthocyanins are less abundant in banana,asparagus, pea,
fennel, pear, and potato, and may be totally absent in certain
cultivars of green gooseberries

28. Tannins:
Occurrence:
 A tannin are special compounds ,water soluble polyphenolic
compounds with molecular weight between 500-3000.
 The tannin compounds are widely distributed in many species
of plants, where they play a role in protection from predation.
 They are commonly found in both gymnosperms as well as
angiosperms.
 The most abundant polyphenols are the condensed tannins
and comprising up to 50% of the dry weight of leaves.
 Tannins are found in leaf, bud, seed, root , stem tissues and
vacuoles or surface wax of plants, mostly found in the growth
areas of trees.

29. Structure of tannins:
There are three major classes of tannins:
1. Hydrolyzable tannins(Gallic
acid)
2. Non-Hydrolyzable or
condensed tannins(Flavone)
3. Phlorotannins(Phloroglucinol)
 Typically, tannin molecules require at least 12 hydroxyl
groups and at least five phenyl groups to function as
protein binders.
 Chemical group is O-heterocyclic compounds.
 Particularly in the flavone derived tannins, the base
shown must be (additionally) heavily hydroxylated and
polymerized in order to give the high molecular weight
polyphenol

30. Chemistry:
 It is an astringent, bitter plant polyphenolic compound that
binds to and precipitates proteins , gelatins and alkaloids.
 Tannins range in color from yellowish –white to light brown.
 Their ability to precipitate proteins makes them available as
clarifying agents.
 Bark of the oak tree and grape seeds are sources of tannins.

31. Betalains:
Occurrence:
 The name "betalain" comes from the Latin name of the common
beet (Beta vulgaris), from which betalains were first extracted.
 Betalains are a class of red and yellow indole derived.
 These pigments found in plants of the Caryophyllales, where
they replace anthocyanin pigments.
 They are most often noticeable in the petals of flowers, but may
color the fruits, leaves, stems, and roots of plants that contain
them.
 Betalains water-soluble pigments found in the vacuoles of plant
cells

32. There are two categories of betalains:
1.Betacyanins:
 It include the reddish to violet betalain pigments.
 Betacyanins present in plants include betanin,isobetanin,
probetanin, and neobetanin.
2.Betaxanthins:
 They are those betalain pigments which appear yellow to
orange.
 Betaxanthins in plants include vulgaxanthin, miraxanthin,
portulaxanthin, and indicaxanthin
Chemistry:
 Betalains absorb light strongly because their synthesis is
promoted by light.
 They effect strongly by the environmental factors.
 Color is not effected by the pH.

33. • Structure:
 It is now known that betalains are aromatic indole
derivatives synthesized from tyrosine(N-heterocyclic
compounds).
 Each betalain is a glycoside, and consists of a sugar and a
colored portion
 For example, betalains contain nitrogen whereas
anthocyanins do not.
 Sources of betalain are red beet root,swiss chard,cactus
pear and amaranth.

34. Quinones :
Occurrence:
 They are widely distributed in plants , specifically
trees , which gives color of wood and bitter in taste.
 Derivatives of Quinone's are common constituents of
biologically active molecules.
 Some serve as electron acceptors in electron transport
chains such as those in photosynthesis (plastoquinone,
phyllo Quinone) and aerobic respiration (ubiquinone).

35. Chemistry:
• Most Quinone are bitter in taste.
• Their contribution to the color of the plant is minimal.
• Color changes occurs by the addition of hydroxyl groups.
Structure:
• A Quinone is a class of organic compounds that are
formally "derived from aromatic compounds by conversion
of an even number of –CH= groups into –C(=O)– groups
with any necessary rearrangement of double
bonds",resulting in "a fully conjugated cyclic dione
structure".

36.  The class includes some heterocyclic compounds.
 They are oxidized derivatives of aromatic compounds and are
often readily made from reactive aromatic compounds such as
phenols and catechol's.
 These phenolic compounds varying in molecular weight from a
1,4Benzoquinone(monomer), 1,4Naphthoquinone(dimer) and
9,10Anthraquinone(trimer) to a polymer hypercin.
 Compounds with complex substitutes such as
Naphthoquinone, Anthraquinone occur in plants and these
have deep purple to black hues.
1,4Naphthoquinone1,4Benzoquinone 9,10Anthraquinone

37. Xanthones:
Occurrence:
 These pigments are yellow, phenolic pigment's, they
are confused with Quinone's and flavones because
of their structural characteristics.
 Many xanthones are phytochemicals,found in
plants. (In the families Bonnetiaceae,Clusiaceae,
Podostemaceae).
 Some xanthones are found in the pericarp of the
mangosteen fruit (Garcinia mangostana).

38. Structure:
 Xanthone is an organic compound with the molecular
formula C13H8O2.
 The chemical structure of xanthone forms the central core of
a variety of naturally occurring organic compounds, such as
mangostin, which are sometimes collectively referred to as
xanthones or xanthonoids.
 The xanthone mangiferin occurs as a glucoside in
mangoes.