Cocoa (Theobroma cacao L) is known worldwide for its beans. They
contain about 50% of fat (Asiedu, 1991). Cocoa is very important ingredient
in several kinds of foods, such as chocolate, cakes, biscuit, child-foods,
ice creams and sweet consumed in developed countries (Guehi et al.,
2007). The fat from cocoa also called cocoa butter is particularly
used in cosmetics, pharmaceutical industries.
In the time, the cocoa’s economy of the most developing and particularly
Côte d’Ivoire based primarily on their agricultural resources
is strongly dependent on the standards and the often rigorous and rigid
quality standards fixed by the developed countries (Guehi et al., 2007).
Otherwise, for several reasons, namely the expensive price of cocoa butter,
chocolate industries are currently envisaging partial substitution of
cocoa butter by other vegetal fats (Hoda et al., 2006; Osborn et
Akoh, 2002; Lipp et al., 2001). Because of these opportunities
about to replace cocoa butter by others fats, cocoa’s economy could
be negatively affected, serious drawbacks should affect smallholder farmers
and raw cocoa bean quality could go to lower.
In order to circumvent such situation, cocoa traders should work in favour
of the wealthy by exploiting by-products namely shells and juice. Indeed,
during cocoa harvesting, cocoa beans are collected in tanks for fermentation.
From mucilaginous pulp embedding beans, a sweetened and vicious juice
pours in abundance.
Nowadays, several policies are being directed in cocoa by-products valorization.
These researches are mainly related to cocoa pods and the mucilaginous
juice, widely used. In Nigeria and Ghana, cocoa pods were used for soap
fabrication (Antonio et al., 1993). These pods were also used for
poultry feeding (Wood and Lass, 1985) for tropical region where conventional
animal foods are highly in concurrence with those of human being. The
juice has been successfully used in Brasilia for alcoholic beverage, vinegar
(Samsiah et al., 1991) and jelly fabrication (Wood and Lass, 1985).
Nevertheless, these results seem very limited and practically unexploitable
at wide scale. This situation is favoured by the lack of complete and
detailed information about chemical and physical characteristics of the
indicate derivated products. Cocoa bean juice could be used in industrial
processes for beverages manufacture such us pineapple, orange and other
many tropical fruit juices if its production is supported and improved
in the on-farm processing of cocoa. In addition cocoa bean juice can be
used for alcoholic drinks, due to its high sugar contents (Redgwel et
al., 2003; Sandra et al., 2007). Several micro-organisms namely
yeasts like Saccharomyces cereviciae and Hanseniaspora guillermondii
and bacteria like acetic acid bacteria (AAB), lactic acid bacteria
(LAB) are present in the juice (Nielsen et al., 2007) can favour
the production of others products by alcoholic fermentation. Côte
d’Ivoire, Ghana and Indonesia are the three countries with the largest
amount of land in cocoa production worldwide and they are also the three
largest cocoa producers. They produced 14,05,000, 736,000 and 41500 metric
tons during marketing year (2003/2004), respectively (ICCO, 2004). The
amount of cocoa juice produced each year is estimated to 300,000,
160,000 and 90,000m3. This juice is used in a small quantity
by farmers for beverage consumption and the mucilage coating placenta
is sucked then the placenta is thrown in farms during cocoa pods opening
processing. Although ivorian farmers hope in further higher price of beans,
they should reorganize cocoa industry by adding value on cocoa bean juice
in industrial area.
The purpose of this study is to transform cocoa bean juice into marmalade.
This was carried out following three steps: determination of chemical
and physical properties, possible preparation of marmalade from cocoa
bean juice and evaluation of sensory properties of the final product.
Materials and Methods
Cocoa bean juice extraction: Cocoa bean juice was collected immediately
after cocoa pods opening from three big cocoa farms around Abidjan (South
Côte D’Ivoire) in September, 2007. Fresh cocoa beans were
packed in a basket and placed at around one a meter up from the ground.
Baskets are slightly bent in order to collect the juice in bottle. Juice
was immediately stored in cool box during the transport to the laboratory.
Chemical analysis: Total soluble solids were measured with a refractometer
(JP SELECTA, Spain) graduated from 0-30 and results were expressed in
degree Brix. The pH was measured with a pH meter (107 Consort, Belgium)
using an agitator (JP SELECTA, Spain). The determination of ash content
and moisture was made using the constant weight method. Crude cellulose
content was measured by Soest method (AOAC, 1976).
Sugars and organic acids contents were assessed by the HPLC while minerals
were evaluated using atomic absorption spectrophotometry. The HPLC system
(shimadzu corporation, Japan) used, was equipped with a pump (shimadzu
LC-6Aliquid Chromatograph), a detector (shimadzu, SPD-6A UV spectrometric
detector) and an integrator (shimadzu C-R 6A Chromatopac).
Fat and ascorbic acid contents were estimated using a Soxhlet extraction
apparatus and 2, 6 dichlorophenol indophenol, respectively (AOAC, 1976).
Titratable acidity was determined using volumetric measurement (AOAC,
1976). Protein content was evaluated with a folin phénol reagent
(Lowry et al., 1951).
Cocoa juice marmalade preparation: The marmalade was prepared
following Unipectin method using 915g of fresh cocoa bean juice and 165g
of crushed placenta. The mixture was boiled in order to evaporate water.
When total soluble solids of the mixture reached 25%, 750g of sugar was
added. When the marmalade reached 60% of dry matter, the heating was reduced
for eight minutes while mixing continue. A drop of marmalade was placed
in a glass in order to verify its cooking. (As the cooking of marmalade
is reached when the drop in the bottom of the glass is easily removed).
The marmalade was then placed in hot sterile jars and kept until the following
Sensory evaluation of cocoa marmaladel: For sensory analysis,
the marmalade was stored at ambient temperature for a month production
and then it was compared to commercial apricot marmalade for many properties
such as taste, color, flavor, consistency and overall acceptability.
A portion (5g) of sample was served in randomly coded plastic plates
to 25 untrained assessors. Each attribute was rated on 1-5 point hedonic
scale where 1 designed “very bad” and 5 “very good”
(SSHA, 1990). For consistency, an additional 5g of each sample was smeared
on a slice piece of bread (Egbekun et al., 1998).
Statistical analysis: The results of sensory test were statically
analyzed using the t-test software STATSOFT STATISTICA 99th
Results indicated that cocoa bean juice had a high nutritional value
due to its contents in fat, carbohydrate, crude protein, mineral and vitamin.
The chemical and physical properties are summarized in Table
1. They showed that cocoa juice was very acidic. This acidity was
revealed by a low pH (3.75) and a high titratable acidity at 170±6.28meq/L.
Citric acid was the most predominant organic acid, with an average value
of 9.14±0.64mg/L. Malic and acetic acids contents were 3.6±0.5mg/L
and 2.28±0.7mg/L, respectively. The juice was very poor in oxalic
acid (1.27±0.72mg/L), lactic acid (1.23±0.01mg/L) and fumaric
acid (0.02±0.01mg/L) (Fig. 2). The total soluble
solids were 16.17o Brix. The sweetness was mostly due to its
high glucose contents averaging 214±6.42g/L. The juice was poor
in saccharose which content was ranged from 21.31±3.21g/L (Fig.
The mineral content was 3.76±0.84% and was represented by potassium
(950±6.32mg/L), calcium (171.5±34mg/L) and magnesium (82.5±0.85mg/L);
Sodium and phosphorus contents were 62.47±3.43mg/L and 30.5±3.77mg/L,
respectively. The crude proteins content was estimated to 7.2±0.21g/L/L,
respectively. Vitamin C content was 18.3±7.5mg/L and the fat content
was estimated to 3.54±0.2%.
The nutrient composition of cocoa marmalade is reported in
Table 2. Similarly to the juice, marmalade had a low pH value (3.14).
The amount of Vitamin C decreased at 2.35±0.25mg/100g. Fat, brut
cellulose and total soluble solids contents were 5.23%, 5.36% and 67.14%,
Table 3 showed the results of sensory tests. There
was no significant difference (p = 0.05) in many properties such as astringency,
taste, colour and consistency between cocoa juice marmalade and commercial
apricot marmalade. However, the aspects and the acceptability of the two
products were significantly different (p = 0.05). On 1-5 rating scale,
the acceptability of cocoa marmalade (3.56±0.7) was fairly lower
than that of commercial marmalade (3.96±0.5). The rating values
of the aspect, colour, taste, astringency, flavour were also lower than
those of apricot marmalade.
Cocoa bean juice contains significant amount of several nutrients such
as (sugar, minerals, fat and proteins). Compared to commonly consumed
orange and pineapple juices, calcium content in cocoa juice is higher
than orange and pineapple juices (Favier et al., 1993). The contents
of other minerals are similar to those found in these fruits.
The pH value of cocoa bean juice was slightly higher than that of orange
juice (3.23-3.53) as reported Esteve et al. (2005).
The low pH and high total acidity were mostly due to the presence of
several organic acids such as citric acid and acetic acid. These acids
preserve the color, flavour and gustative characteristics of the juice
according to Navarre (1998). So they could preserve cocoa juice of the
bacterial contamination. Finally the low pH also contributes to the preservation
of the microbiological quality of the juice by protecting it from non
acidophil bacteria (Delanoë et al., 1996).
Cocoa juice was high in sugar compared to that found in pineapple (12.5o
Brix) (Regina et al., 2006) and in mandarin juice
(52.2g/L of saccharose and 20.8g/L of glucose) (Ana et al., 2004).
Identification and quantification of reducing sugars in cocoa bean
juice with HPLC method. a: Glucose; b: Saccharose.
Identification and quantification
of organic acid
s in cocoa bean juice with HPLC method. a: oxalic acid;
b: citric acid; c: malique acid; d: acetic acid; e: fumaric acid.
These sugars have a key role by covering the astringency due to the organic
acids. Fat and protein contained in cocoa bean juice were higher than
those found in orange (3.12%) (Saïdani et Brahima, 2003) and (3.15-5%)
(Latham, 2001), respectively.
||Physical and chemical characteristics
of cocoa bean juice
of three determination
chemical Properties of Cocoa Beans Juice Marmalade
of three determination
Evaluation? Score Results of Marmalade Samples
with the same letters within a column do not differ significantly
(p = 0.05). *Range: 1 = very good, 5 = very bad.
Cocoa juice can not be considered as a veritable source of vitamin C
in comparison with that found in orange (77±3mg/L) or pineapple
(26.5ml/L) (Yurena et al., 2006).
Cocoa marmalade had a comparable nutritional value as commercial marmalade.
The highest consistency of cocoa marmalade could be attributed to the
pectin contained in cocoa fresh juice. During marmalade preparation, the
pectin formed a gel, resulting in an increased consistency of the product
according to Emaldi et al. (2006).
The lower sugar content also induced the lower output of the marmalade
manufacturing. Marmalade cooking needs 50% of sugar. This amount was higher
than the quantity of sugar added during the cocoa marmalade formulation
which used 41% of sugar. The addition of placenta also increases the amount
of the crude cellulose content in cocoa marmalade which was higher than
the marmalade cooked with lupines fruits which containing 0.2-0.8% of
crude cellulose (Villarreol et al., 1996).
Due to its higher nutritional value and the quantity, cocoa bean juice
should be valorized with two objectives: for beverage consumption like
tropical juice (orange, pineapple) and for marmalade preparation. On the
basis of the current (2003-2004) cocoa production and the outcome of the
manufacture (46.2%), more than 140, 74.6 and 42 tons of marmalade are
expected to be produced by Côte d’Ivoire, Ghana and Indonesia
respectively. This production (239.2 tons) would increase if other cocoa
producing countries (Brazil and Nigeria) were considered.
Beside the beans, cocoa juice should be involved in cocoa industries’
policies. Like cashew nut valorized in Tanzania, India and Brazil (Lautier
et al., 2001) and pineapple industry restructured in Martinique
(Saudubray et al., 2006), the perspective of cocoa manufacturing
is necessary. Cocoa juice could stand out presently because the world
market for certified citrus (fresh and juice) offers interesting prospects.
It is low and represents only 0.3 percent of the world juice consumption
and 0.1 percent of world juice production (Pascal Liu, 2004). So the exportation
of 550 millions of liters of cocoa juice or 192 tons of marmalade should
comply with new requirements for food security.
Conclusion: Valorization of fresh cocoa mucilaginous juice results
from economical considerations. This juice production with its diversity
of products (beverage and marmalade) seems to be able to constitute an
interesting source of incomes for cocoa producing countries. Cocoa juice
has a nutritional value (quantity and nutrient content) comparable to
that of some tropical fruits and cocoa marmalade has an acceptable quality
like some commercial products such as apricot marmalade.
Nevertheless, these new products should be more studied in order to find
a long storage for the beverage and increase the input of the marmalade
production. This perspective is important because cocoa juice is presently
a by-product of cocoa industry with a strong economic potential.