6.7 Key Products and Final Markets for Commercialization
Tropical roots and tuber crops are utilized in a wide variety of ways and their versatility has facilitated major changes in their importance around the world in response to shifting supply and demand in many developing countries (Dayal et al, 1991). Consequently, the development of processed products with functional attributes has the potential to improve commercialization and consumption of tropical roots and tubers (Oloo et al., 2013). The major tropical roots and tubers, sweet potato and cassava, are always used in some form and amount as animal feed wherever they are produced in developing countries (Dayal et al, 1991; IITA 1990). Cassava is an important feed ingredient in Europe, with the Netherlands, Belgium, Germany, Spain and Portugal as the largest markets for cassava feed products (IFAD and FAO, 2000).
In most cassava-producing countries, fresh cassava roots are utilized in a variety of ways. They are peeled, washed and chewed raw in the case of sweet cassava (Kam-bewa, 2010). They are also cut into pieces or sliced and then boiled, roasted or deep fried (Phillips et al., 2004). Cassava roots are marketed fresh for human consumption, and also used as a raw material for more than 300 food and non-food products such as industrial starch, liquid glucose, dextrin, Vitamin C, gums, high fructose syrup (Bal-agopalan et al., 1992), fermented and non-fermented flour, animal feed, glue, alcohol, noodles and a wide variety of fried and baked products (FAO, 2001; Phillips et al., 2004; Scott, 1992; Wiersema, 1992). Cassava is the fourth main source of industrial starch after maize, wheat and potato in Asia ― Thailand, Vietnam and China (IFAD and FAO, 2000) and over 100 cassava starch derivatives (chemically-modified starch) have been developed to provide products with the physical and/or chemical properties required for specific applications in industry (IITA, 1990). Cassava flour is increasingly used as a substitute for wheat flour by both large companies and small and medium enterprises (Kambewa, 2010). Cassava starch, with its highly adhesive nature, is an ideal carbohydrate supplement in fish feeds (Balagopalan et al., 1992).
Although a variety of sweet potato products are attainable, relatively few commercialization cases of the products have been reported (Woolfe, 1992). The roots are predominantly consumed fresh (Ray et al., 2010) after boiling, steaming, baking and canning, but when excess production occurs they may be washed, sliced into small pieces, dried in the sun and milled into flour for utilization during seasons of low food supply (Kapinga and Carey, 2003; Woolfe, 1992). Dried sweet potato slices are utilized by boiling and mashing with beans, and the flour is used as a wheat substitute in sweet potato-based products (CARPA, 2007; Williams et al., 2013). The flour is also mixed with grain flours and used to make porridge, baby food and in bakeries to make bread and cakes (CTA, 2007). Cooked and mashed sweet potato roots are also used to replace some of the wheat flour in bread, cakes and other baked products (CARPA, 2007). In addition, sweet potatoes are processed into syrup, starch and starch-based food products, such as noodles, vermicelli and macaroni, candy and desserts (Bovell-Benjamin, 2010; Moorthy and Shanavas, 2010). Other possible sweet potato processed products are purees and dehydrated forms that can be used as functional ingredients in numerous food products (Truong and Avula, 2010). Industrial application of good-quality sweet potato starch is an important industrial raw material for the local market or export market (Dayal et al, 1991) for the manufacture of sweeteners, citric acid, beverages, alcohol, ethanol, fuel and derived products (Bovell-Benjamin, 2010).
Yam tubers are grown for home consumption (Tetteh and Saakwa, 1994), sold in local markets immediately after harvesting, stored and marketed later when prices are higher, or exported to Europe and the United States, where demand is high among the large immigrant population from the humid and sub-humid tropics (Asumung-Brempong, 1994). The tubers are usually prepared for eating using simple cooking methods such as boiling, baking, roasting, steaming or frying (UNIFEM, 1993). They are also processed into a popular gelatinous paste referred to as “fufu” or dried and ground or milled into flour (Janssens, 2001).
Taro is used for direct human consumption after boiling, frying, roasting and mashing. It can be processed commercially into weaning foods, flakes, breakfast foods, noodles, and canned and frozen goods (UNIFEM, 1993). But it is yet to see the commercial success of cassava and sweet potato.
6.8 Trends in Commercialization
An emerging consensus among specialists in different disciplines suggests that the goal of increasing food production in developing countries can best be achieved by an approach that emphasizes expanded utilization of agricultural commodities (Scott, 1992). At the household level, roots and tubers occupy the position of staple alternating with other staples seasonally at different times of the year, when the other competing staples are in short supply or too expensive (Woolfe, 1992). Consequently, the flow of root and tuber crops to the major markets tends to peak when the supply of competing food products is low at household and market levels (Kambewa, 2010). Increase in population growth and rapid urbanization in tropical developing countries has greatly influenced commercialization by creating demand for food in the urban centres and necessitating sourcing and transportation of produce in bulk from the major production areas including neighbouring countries (Kambewa, 2010; Ngunjiri et al., 1993). Globally, markets demand a consistent supply of products that meet new high standards for food quality and food safety, a situation that increases the comparative advantages of large-scale commercial producers and processors over the small farmers and small-scale traders who find it difficult to penetrate and exploit international markets. Development trends including demographic changes, growth in income, availability of substitute food and feed sources, government agricultural and trade policies and improved production and processing technology have been identified as the key factors influencing prospects for expanding processing and utilization of roots and tubers (Scott, 1992).
Trade policy has been instrumental in shaping the role of cassava as a fully commercial crop entering diversified markets in Asia (IFAD, 2001). According to Gebremedhin and Jaleta (2010), policy, technological, organizational and institutional interventions aimed at promoting commercial transformation of subsistence agriculture should improve market orientation of the smallholder at the production level and also facilitate market entry and participation in the output and input markets. Smallholder farmers usually fail to participate and benefit from large available markets, because their capacity and participation in the value-addition process is limited by insufficient innovative product development and diversification to meet market preferences. It is therefore important to increase the competitiveness of the smallholder producers by increasing value addition through development, introduction and distribution of labour-saving technologies such as peelers, chippers, graters, solar driers and other processing machines (Kambewa, 2010).
In addition, increasing commercialization of smallholder agriculture and international competitiveness will require investment in capacity building of the smallholder farmers, the private and government extension service providers and researchers towards innovative product development and diversification to meet market requirements (Woldewahid et al., 2011). Policy and institutional environment should be aimed at strengthening smallholder cooperatives and farmer groups that supply the agro-processing industry. Research and development institutions should also support the production and commercialization of root and tuber crops, through collaborative efforts involving public, donor and private sectors, in such areas as seed selection, multiplication and distribution of planting materials (Kambewa, 2010). Bringing together the various public and private actors (producers, researchers, extension workers, agri-businesses and service providers) in the process of planning, implementing and monitoring commodity-based research and development programmes, increases access to relevant knowledge from multiple sources and it should be encouraged for the benefit of commercialization (Gebremedhin and Hoekstra, 2008).