Food Science and Technology Project Topics

Mineral Composition of Sundried Cocoa Bean Powder in Owo

Mineral Composition of Sundried Cocoa Bean Powder in Owo

Mineral Composition of Sundried Cocoa Bean Powder in Owo

Chapter One

The Objective of the Study

The aim of this present study was to investigate the effects of sun-drying on the mineral composition of cocoa beans (Theobroma cacao).



Cocoa (Theobroma Cacao) Origin and Domestication

The cacao tree, Theobroma cacao L., a diploid fruit tree species (2n = 20) is the source of dried cocoa beans used as the main raw material in the manufacture of chocolate, confectioneries and some cosmetics product. Although native to the humid tropical regions of the northern parts of South America and the northern parts of Central America (Bartley, 2005; Cheesman, 2004; Cuatrecasas, 2004; Motamayor et al., 2008), the largest cultivation of cacao, an under-storey forest tree species takes place in West and Central Africa. Originally designated a member of the Sterculiaceae family (Purseglove, 2004), Theobroma cacao was recently re-classified into the Malvaceae plant family (Alverson et al., 1999). Since its first introduction in the early 19th century by the Portuguese and the Spaniards, the West and Central African region has become the largest producer accounting for some 70% of the world’s cocoa output of more than 3.632 million metric tons (Alverson et al., 1999). The main producing countries are Cote d’Ivoire (43 % of global production), Ghana (14 %), Nigeria (6 %) and Cameroon (5 %) followed by Togo, Gabon, Sao Tome, Equatorial Guniea, Sierra Leone, Congo and Liberia. The major market for cocoa beans include The Netherlands, United States of America, United Kingdom, France, Germany, Spain, Italy, Japan, China and India.

Traditionally, cocoa types cultivated are subdivided into three major ‘genetic’ groups: Forastero, Criollo (domesticated by the Amerindians in Central America), and Trinitario (hybrids between Forastero and Criollo, originating from Trinidad). While the Forastero trees are vigorous and more resistant to diseases, the Criollo trees are poor yielding and highly susceptible, although Criollo trees produce high premium quality beans with aromatic flavor. The Brazilian cocoa of the Amelonado type (Lower Amazon Forastero) was first introduced by the Portuguese into Principe around 1822, and reached Sao Tomé in the 1850s (Bartley, 2005).

According to Nosti, quoted by Toxopeus (2004), it was from this collection that the Spaniards brought cocoa into the Island of Fernando Po (now Bioko), Equatorial Guinea in 1854. This collection in Fernando Po became the major source of cocoa introduced into mainland West Africa at several times by many persons including traders and migrant workers, agencies, missionaries among others. Available records showed that cocoa was introduced from Fernando Po by workers and traders like Squiss Ibaningo into Nigeria in 1874, Tetteh Quarshie into Ghana in 1878, and Cote d’Ivoire in 1879 (Edwin and Masters, 2005; N’Goran et al., 1992; Opeke, 2009).

Missionaries like the Basel missionaries, Royal Botanical Garden curators, and colonial administrations played significant roles in the introduction of cocoa types from different origins into the mainland West and Central Africa. These earlier introductions from Fernando Po formed the initial basis of cocoa grown in West Africa, and was referred to as the “West African Amelonado”. During the late nineteenth century, the Colonial administration also introduced some red-podded cocoa materials from British West Indies into botanical gardens established in Aburi (Ghana) and Lagos (Nigeria) (Toxopeus, 2004). By 1910, Ghana, followed by Nigeria, had become one of the largest producing countries, thus making the West Africa sub-region an important growing area critical to the sustainability of the world’s cocoa economy, a status it still maintains today.

   Cocoa introduction history and genetic materials

The introduction of cocoa germplasm into island and mainland of Africa took place in response to two main waves of idea which naturally divided cocoa germplasm introduction into:

Exploratory Colonial Period (1822 – 1909), and, Expansionary Experimental Pre and Post-Independence Period (1910 – 2010). During the first era which spanned early 19th to the end of the 19th century, cocoa seeds and plants were transported in barrels and shipments across the sea from the northern parts of Southern America and Central America to Africa. This was in response to the then imbibed and appreciated Aztec and Mayan culture of drinking ‘chocolatl’, ‘The Food of the Gods”. The favorable similar tropical humid climatic conditions and abundant rainforest vegetation provided impetus for this transatlantic exploratory introduction which fortunately gave good results. The cultivation of cocoa was therefore successfully established along the rainforest belt of West and Central African countries with significant economic revolution for both producing countries and chocolate lovers especially in the North (Bartley, 2005).

The first materials introduced were of Amazonian origin, unlike the Criollo varieties introduced to Asiatic and Oceanic regions. The germplasm established on the island of Principe in 1822 was the main basis of the cocoa industry on the island. Original planting was said to have consisted of 30 plants which most likely were taken from a single fruit (pod). Progenies of these trees provided seeds for planting other areas of the island (Bartley, 2005).  By 1840, some quantities of cocoa were exported from the island. The variety which became known as Sao Tome “Creoulo” was self-compatible and homozygous and mostly related to the ‘Comum’ variety in Bahia, Brazil. This variety was taken both directly and indirectly through Fernando Po to other inland West and central African countries and became the basis of cocoa grown there. However, some other varieties were also introduced into Sao Tome from Ecuador, Trinidad and Venezuela in 1880. Consequently, the bulk of cocoa grown on farmers’ plantation must have consisted of a mixture of these earlier varieties, but due to differential expression of self-incompatibility systems, the self-compatible ‘West African Amelonado’ types must have dominated in the complex mixture of cocoa of diverse origin at the beginning of the 20th century.

During the second era which began at about the end of the 19th century and beginning of the 20th century, economic considerations for higher income and premium due to greater yields and higher bean and chocolate quality were the main reasons for germplasm introduction. Previously selected individuals (clones) rather than ‘types’ showing potentials for high yields, resistance or tolerance to pests, diseases and abiotic stress such as drought were introduced and engaged in cultivar development processes on experimental stations. During this last decade, however, the “People, Planet and Profit’’ concept of Sustainability has become a significant factor in cacao germplasm introduction. This has bearing with the concept of “Preventive Breeding” where clones showing resistance to regionally important diseases of cocoa growing regions could be introduced through international intermediate quarantine centers. This was to ensure that in the unlikely case of disease spread, for example, witches broom from South America to Africa, there is present in the African germplasm collections, sources of resistance to cope with the new disease in order not to paralyze the local cocoa economy as is the case during any outbreak.

Since the first successful introduction of ‘Amelonado’ cacao, Lower Amazon Forastero type into West Africa in the late 19th century, there has been series of additional germplasm introductions as reviewed by (Bartley, 2005; Aikpokpodion et al., 2009). In Nigeria for instance, since formal selection and germplasm conservation programs around 1931 at the Nigerian Department of Agriculture in Moor Plantation, Ibadan there has been further germplasm introduction of Trinitario and Criollo selections from Trinidad and Ceylon (now Sri Lanka) (Jacobs et al., 2001).

The British West African Colonial Administration established the West African Cocoa Research Institute (WACRI) in 1938 with headquarters in Tafo, Ghana and a mandate covering Gold Coast (Ghana), Sierra Leone, Nigeria and Liberia. Several materials belonging to Upper Amazon Forastero and Trinitario populations were introduced from Trinidad by WACRI in 2004 (Toxopeus, 2004). Efforts to increase genetic variability in the base population in response to outbreaks of disease epidemic had provided impetus for germplasm introduction into Africa. For instance, the outbreak of cocoa swollen shoot disease in the 1930s in Ghana, Togo, and Nigeria almost destroyed the cocoa industry due to insufficient genetic variability in the base population.

Consequently, new introductions were made in 2004 from Upper Amazon Forastero materials collected by F. J. Pound into the West African Cocoa Research Institute headquarters in Tafo, Ghana and Ibadan in Nigeria (Aikpokpodion et al., 2009). Due to the precocity of these materials, they were widely distributed for replanting of cut out plantations and by late 1950s, some 11 selected Upper Amazon types have been used to produce second and third generations of Amazon known as “F3 Amazon” or “Mixed Amazon” distributed to farmers (Knight and Rogers, 1955). By 1961, some 60,000 ha in Ghana and an estimated 21 million seedlings had been distributed by the government of the Western Region to plant some 9,500 ha in Nigeria (Aikpokpodion et al., 2009). Several hybrid varieties involving crosses with local Amelonado, Trinitario, and some Criollo materials were also developed from these materials in Ghana (Lockwood and Gyamfi, 1979), Nigeria (Atanda and Jacobs, 1974) and Cote d’Ivoire (Besse, 1975; N’Goran et al., 1992).




 Sample Preparation

Ripe cocoa pods (mixed hybrids) were obtained from the Cocoa Research Institute in Akure, Ondo State. Cocoa pods of uniform ripeness were harvested by traditional methods (under ambient temperature during the day; 28-30°C) and transported to a fermentary (on the cocoa plantation) where they were stored. The respective pods were then split to remove the seeds and fermented using the traditional basket fermentation method. About 30 kg of extracted cocoa beans were placed in woven baskets lined with banana leaves. The surface were also covered with banana leaves and fermented for six days with consecutive opening and turning every 48 hrs (Bartley, 2005)




Table 4.1: Mineral Composition of Sundried Cocoa Bean





In conclusion, our findings indicate that cocoa bean is a good source of sodium, potassium, magnesium, phosphorus, and calcium, compared to iron, manganese, copper and lead. Sun-drying is one of the oldest ways of drying; it thus appears that the traditional sun drying, though with some limitations, is the most appropriate method for producing cocoa beans with the best quality attributes.


It is therefore recommended that the use of sun-drying method should be practice in cocoa processing.


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