**2. Sources of starch**

Starch is a source of carbon and energy, it is predominantly found in different part of a plant such as stem, roots, flowers, seeds, and fruits [3]. Starch can be derived from tubers and cereals, such as cassava, potatoes, maize, yam, rice, etc. [14]. **Table 1** shows the starch compositions of some crops. The starch contents of cereals and tubers presented in **Table 1** ranged from 20.48–77.90%, with soft wheat having the highest value and bitter yam having the lowest value.

#### **2.1 Cassava**

Cassava (*Manihot esculenta* Crantz) is a tropical valuable root crop, used both as food and industrial raw material, due to the high starch content in tubers [22, 23]. It is one of the world's most important food crops, with annual global production at approximately 276 million metric tons in 2013 [24]. Its price is often decided by the industrialists based on the percentage of starch in the tubers. In 2013, the top producing countries globally were: Nigeria (accounting for 19% of the total), Thailand (11%), Indonesia (9%), Brazil (8%) and Democratic Republic of Congo (6%) [24]. It is a source of livelihood for at least 300 million people. Nearly 90% of cassava produced in Africa is used as a staple food for human consumption, which provides calories for 500 million people and it constitutes 37% of the population's dietary energy requirements [24]. Cassava is perceived in most African countries both as a food security crop and also as a raw material for various types of industries. It can be transformed into several types of products ranging from traditional foods and feeds to novel food products [24, 25].

#### **2.2 Potatoes**

Potato is one of the top four staple food crops in the world. Majority of its production is meant for human consumption (50–60%), while the rest are used for production of animal feeds, industrial products and as seed tubers [26, 27]. The tuber is a carbohydrate reserve and it also contains high quality protein, substantial amounts of vitamins, minerals and trace elements. Potatoes grow best in moderate

**197**

products [27].

*Starch compositions of cereals and tubers.*

**2.3 Yams**

**Table 1.**

*Utilization of Starch in Food and Allied Industries in Africa: Challenges and Prospects*

**Food Plants Starch Contents (%) Sources**

Waxy rice 74.76 Moongngarm [15] Hard wheat 77.40 Ragaee *et al*. [16] Soft wheat 77.90 Ragaee *et al*. [16] Barley 53.60 Ragaee *et al*. [16] Millet 67.40 Ragaee *et al*. [16] Rye 58.00 Ragaee *et al*. [16] Sorghum 67.70 Ragaee *et al*. [16] Fonio 68.00 Cruz *et al.* [17] Sweet Corn 36.23 Moongngarm [15]

Sweet potato 52.54 Moongngarm [15] Lesser yam 54.70 Moongngarm [15] White yam 58.02 Moongngarm [15] Water Yam 31.90 Brunnschweiler *et al*. [18] Bitter yam 20.48 Ezeocha and Okafor [19] Potato yam 38.10 Shajeela *et al.* [20] Yellow yam 41.72 Oladebeye *et al.* [21] Taro 63.74 Moongngarm [15] Cassava 65.71 Moongngarm [15]

climate, where continuous cultivation throughout the year is impossible [26]. Among the potato varieties, sweet potato (*Ipomoea batatas* L (Lam)) is regarded as one of the most economically important species, as it can grow in great abundance on marginal soils [27]. It is rich in starch (58–76% on a dry basis) and the starch is widely used in starch noodles, bakery foods, snack foods and confectionary

Yams belong to the family *Dioscoreaceae* and they are annual or perennial tuber-bearing and climbing plants. It is an important major food crop in Nigeria [28] and ranked as the fourth major root crop in the world after cassava, potatoes and sweet potatoes, having an annual production of above 28 million metric tonnes [29]. However, Nigeria was rated as the world's largest producer of yams, with *Dioscorea rotundata* and *Dioscorea alata* as the two most cultivated yam species [30]. Yam can be explored for commercial starch production because of their high starch content of about 70 to 80% dry weight [31], and it plays a prominent role in ensuring food and livelihood security of at least 60 million people in West Africa. Globally, roughly about 57 million tons of yams (representing 93% of annual global production) are produced on 4.7 million hectares annually in this sub-region which comprise of Benin, Côte d'Ivoire, Ghana, Nigeria, and Togo [24, 32]. The yam species that are majorly grown globally include: *Dioscorea alata* (water yam), *Dioscorea bulbifera* (potato yam), *Dioscorea cayenensis* (yellow yam), *Dioscorea dumetorum*

*DOI: http://dx.doi.org/10.5772/intechopen.95020*

**Cereals**

**Roots/ Tubers**


*Utilization of Starch in Food and Allied Industries in Africa: Challenges and Prospects DOI: http://dx.doi.org/10.5772/intechopen.95020*

#### **Table 1.**

*Innovation in the Food Sector Through the Valorization of Food and Agro-Food By-Products*

mechanical properties [5].

way outs.

**2.1 Cassava**

**2. Sources of starch**

feeds to novel food products [24, 25].

Starch is derived from a range of raw materials such as corn, wheat, pea, potato, and cassava roots [9] and it has a wide range of applications beyond the food industry. It is also used in the paper/board sector for wet-end addition, size press, surface coating and in the production of recycled paper. It is also used as a binding agent in the pharmaceuticals sector, as an adhesive in industrial binding sector and as a stiffener in the textile sector [10]. Other non food applications of starch include utilization as alcohol-based fuel, low-calorie substitutes, biodegradable packaging materials, thin films and thermoplastic materials with improved thermal and

Starch is the basis of our food and industrial economy, but the food situation in most developing tropical countries is alarmingly worsening owing to increasing population and shortage of fertile land [11]. The shortage of food supply has resulted into a high incidence of hunger and malnutrition [12, 13]. It also affected the demand for starch as food, pharmaceutical and industrial uses coupled with the need to attain self-sufficiency in starch production. However, the focus of this review is to critically appraise the challenges that food and allied industries are facing on the utilization of starch as their major raw materials and to suggest possible

Starch is a source of carbon and energy, it is predominantly found in different part of a plant such as stem, roots, flowers, seeds, and fruits [3]. Starch can be derived from tubers and cereals, such as cassava, potatoes, maize, yam, rice, etc. [14]. **Table 1** shows the starch compositions of some crops. The starch contents of cereals and tubers presented in **Table 1** ranged from 20.48–77.90%, with soft wheat

Cassava (*Manihot esculenta* Crantz) is a tropical valuable root crop, used both as food and industrial raw material, due to the high starch content in tubers [22, 23]. It is one of the world's most important food crops, with annual global production at approximately 276 million metric tons in 2013 [24]. Its price is often decided by the industrialists based on the percentage of starch in the tubers. In 2013, the top producing countries globally were: Nigeria (accounting for 19% of the total), Thailand (11%), Indonesia (9%), Brazil (8%) and Democratic Republic of Congo (6%) [24]. It is a source of livelihood for at least 300 million people. Nearly 90% of cassava produced in Africa is used as a staple food for human consumption, which provides calories for 500 million people and it constitutes 37% of the population's dietary energy requirements [24]. Cassava is perceived in most African countries both as a food security crop and also as a raw material for various types of industries. It can be transformed into several types of products ranging from traditional foods and

Potato is one of the top four staple food crops in the world. Majority of its production is meant for human consumption (50–60%), while the rest are used for production of animal feeds, industrial products and as seed tubers [26, 27]. The tuber is a carbohydrate reserve and it also contains high quality protein, substantial amounts of vitamins, minerals and trace elements. Potatoes grow best in moderate

having the highest value and bitter yam having the lowest value.

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**2.2 Potatoes**

*Starch compositions of cereals and tubers.*

climate, where continuous cultivation throughout the year is impossible [26]. Among the potato varieties, sweet potato (*Ipomoea batatas* L (Lam)) is regarded as one of the most economically important species, as it can grow in great abundance on marginal soils [27]. It is rich in starch (58–76% on a dry basis) and the starch is widely used in starch noodles, bakery foods, snack foods and confectionary products [27].

#### **2.3 Yams**

Yams belong to the family *Dioscoreaceae* and they are annual or perennial tuber-bearing and climbing plants. It is an important major food crop in Nigeria [28] and ranked as the fourth major root crop in the world after cassava, potatoes and sweet potatoes, having an annual production of above 28 million metric tonnes [29]. However, Nigeria was rated as the world's largest producer of yams, with *Dioscorea rotundata* and *Dioscorea alata* as the two most cultivated yam species [30]. Yam can be explored for commercial starch production because of their high starch content of about 70 to 80% dry weight [31], and it plays a prominent role in ensuring food and livelihood security of at least 60 million people in West Africa. Globally, roughly about 57 million tons of yams (representing 93% of annual global production) are produced on 4.7 million hectares annually in this sub-region which comprise of Benin, Côte d'Ivoire, Ghana, Nigeria, and Togo [24, 32]. The yam species that are majorly grown globally include: *Dioscorea alata* (water yam), *Dioscorea bulbifera* (potato yam), *Dioscorea cayenensis* (yellow yam), *Dioscorea dumetorum*

(bitter yam), *Dioscorea esculenta* (lesser yam), *Dioscorea opposita* (Chinese yam), *Dioscorea rotundata* (white yam), and *Dioscorea trifida* (cush-cush yam) [33]. Among the species mentioned above, *Dioscorea rotundata* and *Dioscorea cayenensis* are the most commonly grown for consumption and commercial production. Yam contains mainly carbohydrates with little amount of proteins, lipids and vitamins, and it can provide around 110 calories per 100 grams of products [34]. Yam possesses high in moisture, dry matter, starch, dietary fiber, vitamin B6, but low in saturated fat, sodium and vitamin A contents. Yams contain about 5–10 mg/100 g of vitamin C, and the limiting amino acids are isoleucine and sulfur containing amino acids. They also contain a compound called "diosgenin", which can be extracted and used as base for drugs such as cortisone and hormonal drugs. Some species contain alkaloids (e.g. dioscorine C 13H 19O 2N) and steroid derivatives [34]. However, the nutrient content of yam is compared with other crops in **Table 2**.
