Food Science and Technology Project Topics

Production and Evaluation of Complementary Food Produced From Cocoyam and Pigeon Pea

Production and Evaluation of Complementary Food Produced From Cocoyam and Pigeon Pea

Production and Evaluation of Complementary Food Produced From Cocoyam and Pigeon Pea

Chapter One

The Objective of the Study

            The main objective of this study is to produce and evaluate complementary food from cocoyam and pigeon pea blends.

The specific objective of the study

Specific objectives include the following;

  1. To produce powder from cocoyam and pigeon pea
  2. To examine the proximate and sensory properties of the complementary food



Origin and History of Cocoyam (Xanthosoma sagittifolium)

Xanthosoma spp. originate from tropical America (Crop Trust, 2010); most probably, Central and South America (Ramanatha et al., 2010), where the species are believed to have been domesticated from the wild (Bermejo and León, 1994). Xanthosoma spp. are listed as invasive in many areas of the world (French Polynesia, Florida, the Galápagos Islands, Puerto Rico, and Costa Rica) in addition to being intentionally introduced to several other regions including Africa and Asia (Crop Trust, 2010). It is a more recent introduction to Ghana and West Africa compared with the other prominent genus, Colocassia, which is speculated as being native to the sub-region (Doku, 2006), since there is no known period of introduction of the crop. Xanthosoma is therefore referred to as “new cocoyam” in West Africa. Brown (2000) traced its introduction to West Africa as far as the 16th and 17th centuries, but Wright (2004) reported its introduction to Ghana in 1843 (19th century) by the West Indian Missionaries: There is paucity of information on the species in the region between the 17th and 19th centuries.

Notably, cocoyam cultivation is for over a long period to meets the nutritional needs of about 400 million people around the world especially among populations in developing countries of the world which include Asia, the Pacific Islands and West Africa sub-region (Onyeka, 2014). Nigeria and Ghana are the world’s leading countries in the production of cocoyam (Oke and Bolarinwa, 2012) where it is commonly grown amongst smallholder farmers and contributes immensely to address problem of food insecurity.

 Taxonomy and nomenclature of cocoyam

Cocoyam, in most literature, is a collective name for species of the two most cultivated genera, Colocasia and Xanthosoma, of the edible aroids from the family Araceae (Opara, 2003; Ramanatha et al., 2010). Both genera have diverse species and a wide geographical distribution, spanning the tropical and subtropical regions of Oceania, Asia, and Africa. Thus, each have several local, traditional, and scientific names (CABI, 2013). This, coupled with the morphological similarities between species in a genera, has contributed to the confusion in the use of terminologies for their identification (CABI, 2013; Vaneker and Slaats, 2013). Colocasia has 11 – 16 identified species (Long and Liu, 2001; CABI, 2013) with the most common, Colocasia esculenta, being ascribed with two botanical varieties, Colocasia esculenta var esculenta (commonly referred to as dasheen) and Colocasia esculenta var antiquorium (commonly referred to as eddoe).

The two are commonly referred to as taro and old cocoyam in most communities of West Africa (Doku, 2006). However, this nomenclature has been challenged in recent years with some botanists referring to the two varieties as different species (Opara, 2003; Crop Trust, 2010; Ramanatha et al., 2010; CABI 2013). Thus, there is the need for a taxonomic review of the species to facilitate the dissemination and use of scientific data on the genera.  The genus, Xanthosoma, has been ascribed with 50–60 species (Stevens, 2012), and all cultivated varieties are currently grouped under four species: X. sagittifolium, X. caracu, X. atrovirens, and X. nigrum (X. violaceum) (FAO, 2013; CABI, 2014). Of these, the two most cultivated and economically important ones are X. sagittifolium and X. nigrum (Vaneker and Slaats, 2013). The foregoing classification is however disputable as some identified species cannot be put under any of the four groups (FAO, 2013).

This further necessitates the need for a taxonomic review. For simplicity, it is the norm for researchers to refer to all clones of cultivated edible Xanthosoma spp. as X. sagittifolium (FAO 2013), posing a hindrance to accurate dissemination and use of scientific data on the genus. The original range of the genus is uncertain (CABI, 2014). It is however generally agreed to be highly versatile in its requirements for growth and ease of adaptation to new locations making it an optimal choice crop for many climates (Vaneker and Slaats, 2013; CABI, 2014), and a potential food security measure for developing economies. The existing confusion on its taxonomy and nomenclature, however, is a major drawback to utilization of available scientific data from different areas of indigene in seeking to tap the full potential of Xanthosoma spp. (Crop Trust, 2010; Ramanatha et al., 2010). To date, any meaningful study on its food use must be assessed on the basis of available species in a given location without researchers having the liberty to accurately exploit existing data from other studies as is commonly performed for other root and tuber crops.

In spite of Xanthosoma spp. being the main edible aroid in West Africa (Opara, 2003), and Ghana in particular (Ramanatha et al., 2010; Acheampong et al., 2015), there is a dearth of studies on the properties of indigenous cultivated varieties to inform its industrial application and food use (Opara, 2003; Ramanatha et al., 2010; Acheampong et al., 2015). Notwithstanding the confusion in the taxonomy and nomenclature, Colocasia esculenta (L.) Schott is largely referred to as taro and Xanthosoma sagittifolium (L.) Schott as tan(n)ia, and the two are called cocoyam (s) (Opara, 2003; Ramanatha et al., 2010; Crop Trust, 2010; CABI 2013). In West Africa, Colocasia spp. is called “old cocoyam/yam” and Xanthosoma spp. is called “new cocoyam/yam” because the former is said to be native to the region whereas the latter was introduced (Ramanatha et al., 2010). For the purposes of this review, the use of the word cocoyam refers to Xanthosoma sagittifolium (L.) Schott.




 Collections of Materials

Cocoyam (Xanthosoma sagittifolium) and pigeon pea (Cajanus cajan) were purchased from the main market in Owo, Ondo State. The raw materials (cocoyam and pigeon pea) were processed into flour in the Processing Laboratory of Food Science and Technology, Rufus Giwa Polytechnic, Owo, Ondo State.

 Production Methods

 Preparation of cocoyam flour and pigeon pea powder

One kilogram of Xanthosoma sagittifolium was washed with clean water to remove adhering soil and other extraneous materials. The cocoyam cormels were then hand-peeled under water using kitchen knife, and sliced into sizes of 2cm thickness. One kilogram of pigeon pea seeds were sorted to remove dirt extraneous materials and washed as described by Ikemefuna (1998) after which the seeds were co-fermented with sliced cocoyam for 3 days. After this, the fermented product was wet milled using disc attrition mill (Asiko Al1, Addis Nigeria), sieved with a standard sieve (1.0mm mesh) with portable water, allowed to stand for 1 day, drained and dried in oven at 60oC for 7 hours, sieved and packaged in polythene bag for further analysis




Table 4.1: Proximate composition of complementary food produced from cocoyam and pigeon pea





            This study evaluates complementary food produce from cocoyam and pigeon pea, the result was compared to the cerelac complementary food. The result in the study revealed that the complementary food has low ash content, fat and protein content compared to the control sample, the moisture content of the sample was higher than the control sample but still falls to the ranged recommended by Codex. The carbohydrate content was noted to be higher in both samples. The protein content of the sample revealed that the complementary food needs to be supplemented from higher source of protein, since it falls below the recommended value.


Based on the finding in this study, it is therefore recommended that further study should be carried out to increase the nutritional quality of the complementary produce from the same raw materials as used in this study especially the protein and ash content.


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