Chlorophyll is a crucial pigment for photosynthesis found in various plants and algae, primarily chlorophyll a and b, which have a specific structure that aids in absorbing sunlight. It has multiple uses, including acting as a food additive, a detoxifier, and a stimulant for red blood cell production. The stability and degradation of chlorophyll can be affected by factors such as pH and heat, and it can be preserved through methods like freezing and blanching.

1. CHLOROPHYLL
Chandrima Shrivastava

2. TOPICS
 SOURCES
 TYPES
 STRUCTURE
 CHLOROPHYLL IN PLANTS
 PHOTORECEPTORS
 USES AND BENEFITS
 CHLOROPHYLL DERIVATIVES
 STABILITY
 DEGRADATION
 PRESERVATION
 TECHNOLOGY

3. • dark, leafy greens
• fresh herbs
• blue-green algae
• sprouts
• wheatgrass
• green tea
• green vegetables
and fruits
• sea vegetables
SOURCES

4. TYPES AND SOURCES
Global satellite map of chlorophyll in surface waters: higher
chlorophyll shown in green, yellow, and red; lower in aqua,
blue, or purple.
Chlorophyll indicates the growth of phytoplankton. (Image
courtesy NASA)
Chlorophyll a: occurs universally, mostly in plants
Chlorophyll b: mostly in plants
Chlorophyll c1, c2, c3: found together with chlorophyll a in
marine algae
Chlorophyll d: cyanobacteria,
red algae
Chlorophyll f: cyanobacteria
• In most green plants, chlorophyll
a and b are in the ratio 3:1
• Chlorophyll f absorbs in the
infrared region

5. STRUCTURE
• Chlorophyll is a chlorin pigment, structurally
similar to porphyrin pigments such as heme.
It contains a fully conjugated tetrapyrrole
system (18 pi-electrons)
• The chlorin ring can have several different
side chains, usually a long phytol chain.

6. STRUCTURES
Chlorophyll a
Chlorophyll c1
Chlorophyll dChlorophyll b Chlorophyll c2
(IMAGE SOURCE: http://en.wikipedia.org/wiki/Chlorophy

7. CHLOROPHYLL IN PLANTS
• For efficient photosynthesis,
chlorophyll needs to be attached to
the backbone of a complex protein.
• Attached to the porphyrin is a C20 hydrophobic
chain (phytol) which makes chlorophyll fat-soluble
and insoluble in water and it interacts with the
proteins of the thylakoids.

8. PHOTORECEPTORS
• Effective photoreceptors: conjugated tetrapyrrole
system
• Chlorophylls a and b complement each other in
absorbing sunlight.
• In the green region of the spectrum (500-600nm), light
is mostly reflected, hence plants appear green.
• Chlorophyll absorbs strongly, thus masking other less
intense colors from molecules like carotene, quercetin.

9. USES AND BENEFITS
• Chlorophyll absorbs
energy from the sun and
facilitates
photosynthesis in
plants.
• Chlorophyll is registered
as a food additive
(colorant), and its E
number is E140.
• Chlorophyll is known to
detoxify toxins that
cause cancer.
• Chlorophyll acts like a
physiological stimulant
of red blood cells in the
bone marrow.

10. CHLOROPHYLL
DERIVATIVES
CHLOROPHYLL PYROPHEOPHYTINPHEOPHYTIN
CHLOROPHYLLIDE PHEOPHORBIDE PYROPHEOPHORBIDE
(REF: Jackson, A.H., Structure, properties and distribution of chlorophylls, in Chemistry and Biochemistry of Plant Pigments, Vol. 2,
2nd ed., Goodwin, T.W., Ed., Academic Press, New York, 1976, 1)
-Mg
-Mg
-CO2CH3
-CO2CH3
-PHYTOL
-PHYTOL-PHYTOLChlorophyllase
• Central Mg atom is removed under acidic conditions, replacing it with H+, forming
pheophytins.
• Hydrolysis of the phytyl group of pheophytin with acid or alkali forms pheophorbides.
• Cleavage of the phytyl group without removal of Mg atom produces chlorophyllides.
• Prolonged heating causes decarbomethoxylation at C-10 giving rise to pyro-
derivatives.

11. STABILITY
 In heated vegetables chlorophyll is degraded by change in pH:
Acidic pH(3) - chlorophyll is unstable
Basic pH(9) - chlorophyll is stable
 When plant material is heated, i.e. cooked, the plant cell membranes
break down and cause acid to be released, thus decreasing the pH of the
surrounding solution.
 Mg2+ atom is easily displaced by 2 hydrogen ions result in formation of
olive-brown pheophytin. The reaction is irreversible in aqueous medium.
 Prolonged heating further degrade pheophytin into Pyropheophytin
which has an olive drab color
 The heat induced cellular degradation can also predispose the chlorophyll
pigments to photo-degradation in which they chemically decompose in
the presence of light.

12. EXAMPLES OF
DEGRADATION
Fruit maturation
It may occur on or off the plant.
 Ripening of tomatoes (chlorophyll  colorless compounds); induced by ethylene
 De-greening of bananas (chlorophyll  colorless compounds); induced by
ethylene
 De-greening of lemons and oranges (chlorophyll  colorless compounds);
induced by ethylene
http://plantphys.info/plants_human/fruitgrowripe.sh

13.  Canning of peas [chlorophyll  pheophytin (olive brown)]; induced by heat
 Brining of olives [chlorophyll  pheophytin (olive brown)  pheophorbide
(olive brown) and chlorophyll  chlorophyllide (blue green) 
pheophorbide]; induced by acid and chlorophyllase
 Blanching of snap beans, turnip greens and okra[chlorophyll  pheophytin
(olive brown)]; induced by heat
 Coleslaw processing [chlorophyll  pheophytin (olive brown) 
pheophorbide (olive brown)]; induced by acid and chlorophyllase
PROCESSIN
G
(REF: Heaton, J.W. and Marangoni, A.G., Chlorophyll degradation in processed foods and senescent plant tissues, Trends Food Sci.

14. (IMG SOURCE:
SENESCENCE
Senescence refers to the endogenously-controlled deteriorative changes,
which are natural causes of death in cells, tissues, organs or organisms.
• Ready-to-eat salads (chlorophyll  colorless compounds); induced by
ethylene
• Stored cabbage heads (chlorophyll  colorless compounds); induced by
ethylene

15. PROPOSED MECHANISM FOR DEGRADATION
(IMG SOURCE: http://www2.hu-

16. CHLOROPHYLL DEGRADATION
MECHANISM
 The process involves interconversion of chlorophyll a and b
(chlorophyll cycle), and the release of chlorophyll from its protein
complex followed by dephytlization and pheophytinization.
 Oxidation of the ring structure to chlorins occurs and ultimately
colorless end products form.
 Chlorophylls are degraded in the chloroplast by enzyme-catalyzed
process via pheophorbide a and the red chlorophyll catabolite (RCC)
to give primary fluorescent chlorophyll catabolites (pFCC, or its Cl-
epimer, epipFCC).
 pFCCs are modified further by unidentified hydroxylating enzymes.
 When carrying a free propionic acid group, FCCs are transported into
the vacuole where they isomerize by a spontaneous acid catalyzed
reaction to the corresponding nonfluorescent chlorophyll catabolites
(NCCs).

17. PRESERVATION
 Freezing: Low temperature storage preserves chlorophylls; however,
cold stored products may develop chilling injury symptoms.
 Blanching: Thermal treatment to inactivate enzymes that catalyze
down-grading reactions during storage.
 Irradiation: Treatment with gamma radiation in combination with
storage at 8o or 10oC , does not alter sensory attributes like color.
(IMAGE SOURCE: http://mamaldiane.com/freezing-fresh-basil-whole-leaf/)
FREEZING BLANCHING

18.  Reducing moisture content of vegetables or lowering the water
activity: Addition of agents like KMnO4, which absorbs ethylene, and
sorbitol, which reduces water activity.
 By reducing cooking time and boiling vegetables with the pan lid off
to allow the escape of volatile acids, the production of pheophytin
and discoloration can be minimised.
 Alkaline Medium: Adding a small amount of sodium bicarbonate
(NaHCO3) to the water during boiling raises the pH.
 Substitution of Mg2+: Zn2+ or Cu2+ salts help retain bright green color
of vegetables. Sodium copper chlorophyllin gives blue-green color to
canned foods. Though copper is toxic, the concentration level is too
low to be a toxic hazard.
PRESERVATION

19. PRESERVATI
ON
 Artificial colorants: Tartrazine and green S (dyes) added to restore color.
 Addition of maillard reaction products (MRPs): During heat treatment,
chlorophyll degradation to pheophytin can be minimized by the addition
of MRPs to improve colour stability.
 Gibberellic acid (GA): Chlorophyll degradation delayed in GA-treated
crops
(Ref: Kumar R., Rajamanickam R., Nadanasabapathi S., Effect of Maillard Reaction Products (MRP) on Chlorophyll Stability in Green
Gibberellic acid (GA) Green S

20. TECHNOLOGY
 Production of chlorophyll using algae:
Cyanobacterium Spirulina
 Chlorophyll-Based Phototransistor: Coat a
layer of graphene with chlorophyll
 Artificial leaf: Water-gel-based artificial leaves
containing chlorophyll produce electricity Cyanobacterium
Spirulina
(REF: http://www.technologyreview.com/view/516161/materials-scientists-build-chlorophyll-based-phototransistor/)

21.  Chlorophyll as a water quality parameter
 Infrared chlorophyll to boost solar cells
 Chlorophyll for cancer prevention
TECHNOLOGY
http://www.newscientist.com/article/dn19338-infrared-chlorophyll-could-boost-solar-

22. Thank You