Functions of lecithin in chocolate:Chocolate is a dispersion of a very fine particle in a fat phaseBecause of the presence of the solids, chocolate does not behave as a true liquid and has non- Newtonian properties.Viscosity of liquid chocolate as compared to liquid fat is very high. Addition of lecithin greatly affects the fluidity of chocolate. Chocolate with a working viscosity suitable for molding or enrobing can be prepared with a much lower cocoa butter content if lecithin is present, and since cocoa butter is an expensive ingredient it is economical to reduce it in the recipeConching:the liquid chocolate mass is mixed and at each time new surface of the mass get exposed to air. This helps in flavor development and removal of harshness
Enrobing: this is the mechanical method of coating confectionary centers with chocolate by putting them through curtain of liquid chocolate, followed by cooling Cocoa butter: has unique super cooling properties, which means that the liquid fat in an undisturbed condition will remain in the liquid state well below its melting point.When cooled and stirred under a rigidly controlled conditions , time and temperature can be plotted graphicallyThe shape of the curve can give an idea about the purity and quality of cocoa butter.Properties of cocoa butter including specific gravity, refractive index, IV ,SV, unsaponifiable matter, melting point , free fatty acid percentage, RM and P value
Cocoa - chemistry processing and technology
CHEMISTRY OF COCOA
And cocoA products…
-11FET100( 9 -16).
The Swedish botanist Linnaeus gave cacao tree the name Theobroma cacao or The food
of Gods .
The cacao tree has distinctive gray – brown bark and grows to a height from 15 – 25 ft. The
flowers are about 0.5 inch in diameter. Many are produced but relatively few are
pollinated ,apparently by a small midge .Flowers are produced all year long so that the
flowers and the resulting cocoa pods are found on the same tree . A single tree produce
20-50 fruits per year
The tree must have right conditions for good growth.
It needs a warm and humid environment .
Temperatures of 18-35 degrees are adequate ,but the tree does very well
at temperatures of 40 degrees and at relative humidities approaching 100%.
Good growth requires shade and annual rainfall of at least 50 in.
More is desirable , too much can result in water logging and the
of fungal diseases .
VARIETIES OF COCOA TREE
Criollo Cocoa tree
The criollo has white cotyledons.
The colour is given by anthocyanins the group of chemicals which gives
most blue and red flowers their colours .they are present in pigment cells.
In criollo cocoas ,the coloured anthocyanins are replaced by leucoforms.
Criollo without these anthocyanins is another milder cocoa.
Criollo cocoa used to be regarded as superior quality and was much in
demand .However it is a less vigorous plant and is more vulnerable to
Forastero Cocoa tree
The forastero has purple cotyledons.
Anthocyanins are involved in unique flavour of cocoa. The purple
anthocyanins are associated with the stronger ,more astringent and robust
Development in processing and of new products both enabled the less
desirable features of the forastero to be minimized and use made of their
stronger chocolate flavour,so that the tendency to replace criollo by higher
yielding forastero has been encouraged .
Since forasteros are robust and higher yielding there is a popularity with
the growers of forastero, with their suitability for some products they are now
being consumed in great quantity has resulted in becoming by far the larger
proportion of the cocoa crop.
Trinitario is the cross between the two criollo and the forastero.It
appears to have originated by the hybridization between criollo and forastero.
It is now the important type commerciallly.
Trinitarios include pale beans within their pods produse larger
proportion of beans with purple colour .
However they are grown in some areas their popularity is not as much
Less since they are
present in Leuco form
Stronger due to
Less since it is
susceptible to disease
Found only in
lanka and samoa.
Cocoa has a long supply chain extending from smallholders often in remote, less
developed tropical regions of world ,to factories and consumers mainly in developed
industrial countries. like any crop, it is susceptible to changes in the weather ,to
pests and diseases and to social and economic factors.
WHERE COCOA IS GROWN…???
• Cocoa is grown commercially between 20degree north and south of the
Equator,in areas with a suitable environment for cocoa.
• Main growing areas are: west africa,south east asia and south america.
• 7 largest cocoa producing countries are Ivory coast ,
ghana,Indonesia,nigeria,cameroon,brazil and ecuador.
• Between them they account for90% of the world crop.
• Huge concentration (around 70%) within west africa.
• Ivory coast produces 40%of the world crop.
• About 90% of the world’s cocoa is grown by small holders.
More than 3,000,000 tonnes (3,000,000 long tons; 3,300,000 short tons) of cocoa
are produced each year. The global production was
1974: 1,556,484 tons,
1984: 1,810,611 tons,
1994: 2,672,173 tons,
2004: 3,607,052 tons.
Top Cocoa Beans Producers
(million metric tons)
o Cocoa beans contain about 54% fat.
o The naturally occurring lipid within the cocoa bean is referred to as cocoa butter.
o The three primary fatty acids that make up cocoa butter are oleic acid
(C18:1), stearic acid (C18:0), and palmitic acid (C16:0).
o In general, about 37.5% of the fat within cocoa butter is unsaturated fat and
about 61.4% is saturated fat.
o The triglyceride composition of the fat in cocoa butter is primarily in the
configuration of saturated fat (sn1), unsaturated fat (sn-2), and saturated fat (sn3), with oleic acid being the primary fatty acid in the sn-2 position of the
o Cocoa bean contain a fairly large amount of carbohydrates, contributing
about 31% of dry weight of the beans.
o Most of the carbohydrates are starch, soluble dietary fibers, and insoluble dietary
fibers. A very small proportion is simple sugar (~1%).
o The various sugars present are glucose, fructose , sucrose, raffinose, stachyose
verbascose and many others.
o The concentrations of glucose and fructose decreased after roasting but
levels of the non-reducing sugars, sucrose, raffinose, stachyose and verbascose,
were not markedly affected.
o Approximately 10% of the arabinose content of the polysaccharides was degraded
but, overall, the pectic and hemicellulosic polymers remained intact after roasting..
o Cocoa beans contain 10–15% protein, based on the origin.
o In most seeds, 95% of the protein is comprised of four main fractions:
albumins (water-soluble), globulins (salt-soluble), prolamins (alcoholsoluble), and glutelins (soluble in dilute acids and alkali).
o During fermentation, proteins are degraded by enzymes to polypeptides and
amino acids which are the chocolate flavor precursors.
o Thus during fermentation ,the protein content decreases.
o Cocoa beans are rich in a number of essential minerals, including magnesium,
sulfur, calcium, iron, zinc, copper, potassium and manganese.
o Cocoa beans contain vitamin A, B1, B2, B3, C, E and pantothenic acid.
o Polyphenols constitute one of the most numerous and widely distributed groups
of substances in the plant kingdom.
o Dietary polyphenols have received extensive attention in recent years because of
their potential health benefits such as anti-inflammatory, anti-carcinogenic , antiatherogenic , etc.
o Cocoa beans contain three major groups of polyphenols: catechins or flavan-3-ol
monomers (~37% of total polyphenols content), proanthocyanidins or flavan-3-ol
polymers (~58% of total polyphenols content) and anthocyanin (~4% of total
o Catechin is a flavan-3-ol, a type of natural
phenol and antioxidant. It is a plant secondary
metabolite. It is part of the chemical family of
oThe two stereoisomers found in cocoa are
Catechin and Epicatechin.
o The different other enantiomers can as well be found in chocolate where
the different processes of fabrication can lead to epimerisation by heating.
o The main catechin is (-)-epicatechin with up to 35% of total polyphenol
o When beans are fermented there is a large loss of both (-)-epicatechin
and (+)-catechin, but also the formation of (-)-catechin. The heat of
fermentation may, in part, be responsible for the formation of this
o When beans are progressively roasted at conditions described as low,
medium and high roast conditions, there is a progressive loss of (-)epicatechin and (+)-catechin and an increase in (-)-catechin with the
higher roast levels.
o Proanthocyanidins , refer to a larger class of
polyphenols, called flavanols.
o These are also called condensed tannins, which
are oligomers and polymers of monomeric flavans
linked through specific single (B linkages) and
double (A linkages) bonds
o These secondary plant metabolites have
substantial antioxidant activity.
o It is a flavonoid and imparts the purple colour to
fresh forastero cocoa beans
o It is a water soluble glycosidic compound made
up of a glycone (the sugar portion) and an aglycone
(the non sugar portion)
o During fermentation, it is enzymatically transformed
to become an anthocyanidin aglycone.
o It is a xanthine alkaloid substance found in
cocoa beans and many other plants.
o The cocoa bean contains between 0.10.7% caffeine, 0.2% being the most
common amount found.
o Caffeine is also present in lesser amounts
in the husk that surrounds the cocoa beans,
usually from 0.05% -0.3%.
o The amount of caffeine in the beans
varies with the type of beans and the
degree of fermentation
o Caffeine is consumed for both its stimulatory and psychological
o The cocoa bean is nature’s most concentrated
source of theobromine, a compound closely
related to caffeine.
o Theobromine (theobromide), also known as
xantheose, is a bitter alkaloid of the cacao plant, with
the chemical formula C7H8N4O2.
o It is in the methylxanthine class of chemical
compounds, which also includes the similar compounds
theophylline and caffeine
o But unlike caffeine, Theobromine has only a mild stimulatory effect on the
central nervous system, but it has a slight diuretic action similar to caffeine.
o Despite its name, the compound contains no bromine—theobromine is
derived from Theobroma
o It is also known as dimethylxanthine, is a
methylxanthine drug used in therapy for
respiratory diseases such as COPD and
asthma under a variety of brand names.
o Because of its numerous side-effects,
the drug is now rarely administered for
o Along with cocoa beans,it is also found in tea
but in trace amounts.
o Amounts as high as 3.7 mg/g have been reported in Criollo
Aromatic compounds in
fermented cocoa beans
o The most important aromatic compounds in fermented
cocoa are the following classes:
• Pyrazines (20%)
o Some of these compounds are influenced by
fermentation time, others are not.
o All are affected by the temperature
and time of the roasting protocol.
FERMENTATION AND CURING
The process has to be carried out within
24-48 hours after breaking the cocoa pod.
It takes about 5-7 days on average and
varies according to the species.
Forastero- 5-7 days
Criollo- 1-3 days
It is responsible for the chocolate flavor
and aroma in cocoa and also external
browning of beans.
FERMENTATION AND CURING
•Coca beans do not themselves undergo a fermentation at all
•It is pulp surrounding the beans which is fermented, while an
almost simultaneous ‘curing’ process takes place within the beans
Site: In the pulp
Carried out by
Immediate and initial
process after breaking of
Purpose: removal of pulp
out of the pod
Site: inside the beans
Carried out by
development & partially
responsible for the
MICROBIAL ASPECTS OF FERMENTATION
Micro-organisms are responsible for the
breakdown of the pulp that surrounds the
Their activities result in the death of the beans
and they create the environment that enables
the formation of cocoa flavor precursors
The pulp is an excellent medium for the growth
of micro-organisms since it contains 10-15% of
When the beans are removed from the pods,
the pulp is inoculated naturally with a variety of
micro-organisms from the environment.
There are 3 stages of fermentation:
Stage 1Anaerobic yeasts
Sugar Alcohol + CO₂
Rise in temperature
pH < 4 acidic
Bean death on second day occurs due to
acetic acid and alcohol
Lactic acid bacteria
Sugar & organic acids Lactic acid
LAB are present from start but only
become dominant in 48-96 hrs
Acetic acid bacteria
Also present from start but become
significant at the end when the aeration
Alcohol acetic acid
Increases temperature to 50˚C
The pulp around the beans is sticky and needs
to be separated.
The pulp starts loosening from the bean in the
1st microbial stage.
Turning of the beans aids to the fermentation
In 1st 2 processes the temperature rises due to
the exothermic reactions to almost 49-54˚C
By the end of 3rd stage, the temperature drops
rapidly and most of the pulp has drained away
as a liquid.
Acetic acid penetrates into testa (husk) of cocoa
High temperature and influx of acid:
Kill the bean
Disrupt the internal structure
Cocoa beans are composed of white cells (fats,
proteins) and purple cells (polyphenols)
Due to the disruption compounds in the beans
mix and interact within themselves.
Reactions between storage proteins, enzymes
(proteolytic, polyphenol oxidase, invertase) and
polyphenols result in formation of the crucial
chocolate flavor precursors
Chocolate flavor precursors
•Proteins are degraded by
enzymes to polypeptides and
•Reducing sugars (glucose/
fructose) are released.
Reduction of astringent and
•Part of polyphenols oxidized
into large tannin molecules
•Part of polyphenols and
diffused and exudated from
IMPORTANCE OF FERMENTATION & CURING
There is no chocolate flavor in cocoa bean
Chocolate flavor precursors are formed during
fermentation which help in further flavor
IMPORATANCE OF FERMENATTION & CURING
Fermentation helps in the separation of pulp
Omission of fermentation prevents the
possiblity of ever developing a true chocolate
flavor and defect cannot be removed by later
attempts of fermenting
With lower temperatures the putrefaction
bacteria will start to proliferate and longer
fermentation would cause hammy off-flavors
typical for over fermented cocoa beans
FACTORS AFFECTING FERMENTATION
Extent of ripeness of pod
Quantity of beans
Quantity of pulp
Type of cocoa
Duration of fermentation
Seasonal/ climatic effects
In African countries, it is used as manure
due to its fibrous content
Use of liquid fermented pulp for
manufacturing of vinegar has been
proposed by many. But practical
application has not been tried yet.
Extended process of fermentation
Superficial browning in cocoa beans
continues to deepen
Slow but progressive loss of moisture
Loss of astringency & bitter tasteloosening of
the shell from the bean
Shrinking of furrowed cotyledons into 2
almost separate halves
Moisture content reduced to 6%
The enzymatic action as evidenced by colour
changes in the bean should be allowed to
proceed to conclusion
If the beans are dried too quickly some of the
chemical reactions started in the fermentation
process are not allowed to complete their
work and the beans are acidic with a bitter
If the drying is too slow moulds and off flavors
Temperature should not exceed 65˚C
Types of drying:
SLATY, UNDERFERMENTATED (PURPLE) AND
WELL FERMENTED (BROWN) COCOA
Fermented beans are spread in a thin
layer (1-2 inch deep
Exposed to sun until dry
Beans are occasionally turned for
Sundrying can be carried out on small as
well as on large scale basis
Traditionally there is also a method call
dancing the beans which serves the
purpose of drying and removal of shell
Large scale sun
Dancing sun drying
Small scale sun drying
Enough time for properly
started curing to run to
completion hardly any
danger of premature
death of beans from
Length of time involved
Possibility of moth
Though the advantages are not numerically great, they
are important enough as to be overriding
They can be roughly divided into 2 types:
using rotating drums
using trays, platforms or endless belts
dependence on weather
In shorter time (14-48
Saving in labor
No contamination by
foreign matter (sticks,
Less posibility of mold
Shortens the drying to the
extent that drying
enzymatic action is not
Might increase bitterness
Makes cotyledons fragile
and thus uniform roasting
High acidity retained
Danger of smoke
IMPORTANCE OF DRYING
Sun-drying is best for good quality
Significant lowering of strong acid/sour flavor:
volatile acetic acid evaporates through husk
during slow drying non-volatile lactic acid is
partly transported by water from the bean to the
Strong oxidation browning of polyphenols
leading to reduced astringency and bitterness
Flavor forming reactions occur
Dried beans are
artfully roasted at
200˚F to 250˚F for
one to two hours in
order to develop the
flavor of the beans.
The beans become
brown in color and
CHANGES OCCURRING IN ROASTING
Development of pleasant aromatic complex
Evaporation of organic acids and astringents
of volatile nature
Chemical modification of tannins and other
non-volatile that remain, with consequent
reduction of bitterness
Darkening of cotyledon color to deep
Elimination of excess moisture
Loosening the shell from cotyledon
RXNS INVOLVING FLAVOUR DURING ROASTING PROCESS
• One of the important reaction for flavor development is the Maillard reaction or
• The reactions may be conveniently seperated into three stages
FORMATION OF ADDITION COMPOUNDS
Reducing sugars + amino acids
glucoslyamines or fructoslyamines
(depending upon initial reducing
The isomerizaion product formed during the initial phase are primarily addition
compounds formed from amino acids and sugars
moisture is evaluated by hygrometer probe.
ERH > 40%
- very light roast
ERH = 28-30% - average roast
ERH < 20%
- very dark roast
IMPORTANCE OF ROASTING
Non uniformity in moisture content, age,
ripeness, fermentation and curing
To convert flavor precursors into the type and
intensity of chocolate flavor desired
Roasting duration and temperature varies for
different species as well as for different
Main products obtained from Cocoa beans
-Cocoa butter also called theobroma oil,
is a pale-yellow, pure, edible vegetable fat.
End product of cocoa solids which are lowfat
components and are rich in flavonoids
A food preparation in the form of a paste or
solid block made from roasted and ground
cacao seeds, typically sweetened.
1)Cocoa liquor :
After roasting and drying , the cocoa nib is disintegrated and milled in order to rupture
the cell walls of aggregates and expose the cocoa butter. The resultant product is a
homogeneous mobile paste, a flowing cocoa mass or cocoa liquor
sugar, fat and
Cocoa butter is the natural fat of the cocoa bean .Cocoa butter (hydraulic
expression of cocoa nib) is a light yellow fat, exhibiting a distinct brittle fracture
>20°C, a fairly sharp complete melting point about 35°C, with an incipient fusion
or softening around 30-32°C.
The completely liquid fat displays mark tendency to super cool,(which means that
the liquid fat in an undisturbed condition will remain in the liquid state well
below its melting point.) which must be taken into account during chocolate
enrobing and molding
Cocoa butter is composed of number of glycerides of stearic, palmatic and oleic
fatty acids with a small proportion of linoleic.
The cocoa butter has important functions. It not only forms part of every recipe,
but it also later gives the chocolate its fine structure, beautiful lustre and delicate,
• It is the fat obtained
from good quality
cocoa nib by means
• No refining other
than filtration is
EXPELLER PRESSED COCOA
• Cacao nib is steamed
and expeller pressed
to remove cocoa
• Flavor obtained is
very mild and floral,
if raw beans used.
• If substandard raw
material is used then
butter has to be
subjected to a
• extracted from the cake
residue after expeller
• It is always subjected to
• The cocoa mass/liquor is converted into cocoa powder , the cocoa fat is reduced by
pressing, by means of hydraulic, mechanical pressing or preferentially , horizontally- run
expeller press at a pressure of 400- 500 bar and temperature of 90-100 degree C
• The cocoa powders are divided according to the extent of defatting
Extent of defatting
Cocoa butter content
Lightly defatted powder
20-22% residual cocoa butter
Extensively defatted powder
Less than 20% but more than
• Cocoa powder is widely used in the manufacture of other products e.g. cake fillings,
icings, pudding powders , ice creams, and cocoa beverages
• Cocoa powder can be made by two main processes:-Natural process
The process involves use of simply
unsweetened cocoa powder.
The process involves use of alkalized
unsweetened cocoa powder.
No treatment given.
Cocoa beans are directly pulverized into fine
Cocoa bean Treated with potassium
solution to neutralize acidity
Cocoa powder reacts with baking powder
used in recipes
Doesn’t react with baking powder
So not used in recipes
Lighter in colour than dutch process powder.
Neutralization of acidity makes it dark in
Strong cocoa beans taste
Milder taste compared to Natural process
Flavonols content greater than that in dutch
Lower amounts of flavonols
Natural process cocoa powder
Dutch process cocoa powder
Chocolates were originally made directly from cocoa nibs by grinding them in presence of
Chocolates is now made from nonalkalized cocoa liquor by incorporating sucrose, cocoa butter
, aroma or flavouring substances and occasionally, other constituents (milk ingredients , nuts ,
coffee paste , etc.)
The ingredients are mixed , refined , thoroughly conched and finally , the chocolate mass is
Milk cream 10-20
Whole milk 10-30
It can be described as the working of chocolate flake and crumb into a fluid paste.
The process improves the texture and mouthfeel by reducing the particle size.
The bitterness is further reduced and flavours are more pronounced.
It was suggested that Strecker degradation was not complete at the end of roasting
process and suggested it continued during conching.
Water content is lowered from 1.6% to 0.6-0.8% due to this unwanted flavour
component is removed
30% of acetic acid and 50% of low boiling point aldehydes are volatilize which
gives chocolate a better flavour
There is development of amino acid ( 33-50% ) to that of formed during roasting
which contributes to flavour
Cyclic meachanical and shearing forces are exerted in order to separate the
agglomerates formed during grinding, to coat the particles with fat and to disperse
the cocoa butter phase.
Types are longitudinal , rotatory etc
STORAGE OF COCOA PRODUCTS
• All products , from the raw cacao to chocolate, demand careful storage – dry,
cool, well aerated space , protected from light and sources of other odours. A
temperature of 10-12 degree C and a relative humidity of 55-65% are
• Chocolate products are readily attacked by pests, particularly cacao moths ,
the flour moth and beetles , cockroaches and ants
• Chocolates not properly stored are recognized by a greyish matte surface.
Sugar bloom is caused by storage of chocolate in moist conditions(relative
humidity above 75-80%) or by deposition of dew, causing the tiny sugar
particles on the surface of the chocolate to solubilize and then , after
evaporation , to form larger crystals.
• A fat bloom arises from chocolate fat at temperatures above 30 degree C . At
these temperatures the liquid fat is separated and , after repeated congealing,
forms a white and larger spot
• This may also occur as a result of improper precrystllisation or tempering
during chocolate production. the defect may be prevented or rectified by
posttempering at 30 degree C for 6 h