Food Science and Technology Project Topics

Production and Evaluation of Nutrient Composition of Biscuits Produce From Cocoyam-pigeon Pea and Millet-pigeon Pea Flour

Production and Evaluation of Nutrient Composition of Biscuits Produce From Cocoyam-pigeon Pea and Millet-pigeon Pea Flour

Production and Evaluation of Nutrient Composition of Biscuits Produce From Cocoyam-pigeon Pea and Millet-pigeon Pea Flour

Chapter One

Objective of the Study

            The main objective of the study is to produce and evaluate the nutritional composition of biscuits produce from cocoyam-pigeon and millet-pigeon pea flour.

Specific Objectives

The specific objective of the study includes the following;

  1. To produce flour from cocoyam, pigeon pea and millets
  2. To blends the flours produced in different ratios
  3. To produced biscuits from the flour blends
  4. To determine the nutritional properties of the biscuits produced



Cocoyam (Colocasia spp)

Cocoyam (Colocasia spp) is a taproot, starchy and globular fleshy food of edible aroid family (Araceae) that grows well in sandy, loamy soil that is not water-logged. It performs better in loamy soil with a good water retention capacity. 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 (CABI, 2013; Long and Liu, 2001) 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. However, this nomenclature has been challenged in recent years with some botanists referring to the two varieties as different species (CABI, 2013; Crop Trust, 2010; Opara, 2003; Ramanatha et al., 2010). 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) (CABI, 2014; FAO, 2013). 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 (CABI, 2014; Vaneker and Slaats, 2013), 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 (Acheampong et al., 2015; Ramanatha et al., 2010), there is a dearth of studies on the properties of indigenous cultivated varieties to inform its industrial application and food use (Acheampong et al., 2015; Opara, 2003; Ramanatha et al., 2010).

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) (CABI, 2013; Crop Trust, 2010; Opara, 2003; Ramanatha et al., 2010). 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. For the purposes of this review, the use of the word cocoyam refers to Xanthosoma sagittifolium (L.) Schott.

Nutritional facts of cocoyam

Cocoyam, like other roots and tubers, contains dietary energy which is mainly carbohydrate. It has more carbohydrate than potatoes, about 100 g provides 112 calories. It has low protein content 1-2%, like other root crop proteins, which means that sulfur-containing amino acids are relatively small (Iwe, 2002). However, it contains very low fat and protein than in cereals and pulses. The levels of protein are almost the same as that of yam, cassava, potato, and banana. Despite their high starch content, cocoyam has a higher content of protein and amino acids than many other roots and tuber (Sefa-Dede and Sackey, 2002). The nutritional values of cocoyam are presented in Table 1. The protein content of cocoyam is higher (1.12% for taro and 1.55% for tannia) when compared to other tropical root crops (Owusu-Darko, 2014). Cocoyam, however, is gluten-free and contains high-quality phyto-nutrition profile comprising of dietary fiber, and antioxidants with a moderate quantity of minerals, and vitamins. Valuable B-complex group of vitamins is also present in cocoyam which includes; pyridoxine (vitamin B6), folate, riboflavin, pantothenic acid, and thiamine. Also, the corms contain some important minerals like zinc, magnesium, copper, iron, and manganese.

de Castro et al. (2002) and Monte Neschich et al. (1995). Studied two major globulins from corms of taro by The authors observed the existence of two unrelated globulin families during root development; a G2 and G1 protein which accounts for up to about 80% of total soluble tuber proteins. Cocoyam is very rich in thiamine, riboflavin, phosphorus and zinc and also sources of vitamin B6, vitamin C, and niacin. It contains valuable Bcomplex groups of vitamins such as pyridoxine, folates, riboflavin, pantothenic acid, and thiamine (Ramat, 2014). Cocoyam is prone to microbial attack and deterioration because of its high water content which contributed to the short shelf life of the corm. The leaves are used in feeding pigs because of their nutritive values (Agrid, 2006). The leaves are good sources of vitamins A and C and contain a reasonable amount of protein than the corms. Cocoyam’s richness in B6 makes it good for controlling high blood pressure and protects the heart. Cocoyam contains some dietary fiber, which helps in regulating bowel health, lowering cholesterol levels and controlling blood sugar levels. Cocoyam flesh of about 100 g provides 4.1 g or 11% of recommended daily dietary fiber. The presence of slow-digesting complex carbohydrates leads to a gradual rise in blood sugar levels.

Cocoyam leaves have some phenolic flavonoid pigment anti-oxidants such as β-carotene along with vitamin A, which help to maintain healthy mucous membranes and vision. The corms provide minerals like zinc, magnesium, copper, iron, and calcium. It has low fat, and sodium content and this crop when eaten can aid the prevention of hardening of the arteries, which is attributed to eating foods that are high in cholesterol (Ramat, 2014). Drying can be used to dry aroids into flour for fufu, commonly eaten in Nigeria with stew. In Nigeria, most especially in the southeastern region, some quantity of Tannia is used in soup thickener when boiling and pounding to obtain a consistent paste. Young taro leaves are used for vegetable in South Pacific, also with coconut cream to prepare a dish called “luau,” that are eating with boiled or roasted taro, breadfruit, and banana.




Collections of Materials

The raw materials used in this project work were cocoyam (Xanthosoma sagittifolium), pigeon pea (Cajanus cajan) and millet (Pennisetum glaucum), they were purchased in “Emure market”, Owo Ondo State. Others ingredients such as butter, sugar, flavour, baking powder, salt etc. were purchased in the main market of Owo in Ondo State. The flours and biscuits were prepared in Processing Laboratory of Food Science and Technology, Ondo State.

Methods of Production

 Preparation of cocoyam flour

One kilogram of cocoyam (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. The slices were boiled in water at 100oC for 10 minutes. The pieces of cocoyam were dried in an oven at 60oC for 9 hours after which they were milled into flour, sieved with a standard sieve (1.0mm mesh) and packaged in polyethylene bags for further studies (Figure 3.1).




Table 4.1: Proximate composition of biscuits samples





The proximate composition of both samples (CPB and MPB) was observed to be of no significant difference, although MPB was recorded to higher content in terms fibre, ash and carbohydrate content, while CPB was noted to have higher protein and fat content. Compared to the control sample, CPB and MPB has lower nutritional content indicating that whole wheat biscuits is richer in nutrient compared to both samples in this study. In conclusion, cocoyam-pigeon pea and millet-pigeon pea flour blends (70:30) for biscuit production contain poor nutrients in terms ash, fat, fibre and protein hence, needs supplementation or increasing the blend of pigeon pea to meet nutritional requirement, this will help to fight against malnutrition in developing countries especially among children under the age of 10.


Based on the finding in this study it is therefore recommended that further studies should be carried out on cocoyam-pigeon pea and millet-pigeon pea biscuits in way to increase its nutritional qualities.


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