• The nutritional value of yam flour is the same as that of pounded yam. The yam flour is rehydrated and reconstituted into fufu and eaten with a soup containing fish, meat and/or vegetables. The manufacture of fried products from D. alata has also been attempted recently.
• Instant pounded yam flour (IPYP), which is a processed white powdery form of yam (dehydrated yam flour), can be produced in a desiccating machine (Olatoye et al., 2014). Preservation of yam in brine has been attempted, but with little success. Attempts to manufacture fried yam chips, similar to French fried potatoes have been reported.
Elephant Foot Yam Elephant foot yam is a good source of minerals such as potassium, magnesium and phosphorous, as well as trace minerals like selenium, zinc and copper. It is an important tuber crop of the tropics grown as a vegetable. Petioles are also used as a vegetable. They are used in combination with other vegetables for the preparation of various dishes. Frying is also a common practice for their utilization:
• They can be used in curries, made into chips, soups, stews and casseroles. Food products like noodles, pickles, bread, etc. have also been attempted with the incorporation of elephant foot yam.
1.11 New Frontiers for Tropical Roots and Tubers
The production and marketing of the major roots and tubers share common themes, trends and prospects. However, the majority of the smallholders cultivating these crops do so under less than optimal conditions, with yields below world average and a low degree of market organization. In addition, there is a disjointed, unorganized approach to the development of the trade in such products, particularly the commodity value chains. There is a need to focus on the regional market, and better adaptive technology transfer and upgrading of existing processing and product development technologies. Efforts should be made to promote new technologies, appropriate for use by the rural population, to produce a variety of processed foods. This strategy will generate employment and improve incomes in rural areas.
Initiatives need to be taken, including the characterization of various varieties of tropical roots and tubers found in various countries and value addition. The effective focus is needed to prioritize improving productivity, pest and disease management and post-harvest practices to increase the shelf life of tropical roots and tubers. The commodity value chain scheme for tropical roots and tubers is presented in Figure 1.3. The value chain focuses upon the production and harvesting of roots and tubers as per the calculated demand, along with the focus upon post-harvest handling and value addition. The proper implementation of a commodity scheme will assist food security, better income for farmers and improved communication. The different stages shown in Figure 1.3 require systematic efforts in totality to bring roots and tubers on a commercial scale parallel to cereals.
Figure 1.3 Commodity value scheme for tropical roots and tubers.
1.12 Future Aspects
Roots and tubers are essential components of the diet in many countries. In Africa, it has been estimated that nearly 37 % of the dietary energy comes from cassava. Roots and tubers have the potential to provide more dietary energy per hectare than cereals. Taro and cassava can be grown in tropical climates all the year round, which may prove beneficial to provide increased food security. Many food-deficit countries are forced to import large quantities of grain to meet local production shortfalls, which places a burden on the national exchequer.
Despite research on roots and tubers, many issues still need to be addressed such as improved production, energy management and post-harvest handling and utilization in foods and feed. Therefore, strategies need to be developed to address these issues so that root and tubers can play a better role in ensuring food security, sustainable farming and sustainable livelihood development. However, low productivity, limited value addition and poor access to markets are the issues required to be tackled globally. With the current global shortage of food grains coupled with the ever-increasing human population, the root crops as a whole will certainly be the answer in future to food crisis, because of their high productivity and ability to grow under rain-fed and adverse climatic conditions.
Research and development along with the commercialization of roots and tubers is limited and its potential has not been tapped. Therefore, a well-designed, integrated strategy of production, processing and marketing to stimulate increased utilization is needed. The system can be made more effective regarding the research on tropical roots and tubers by creating database development for production, processing, trade and consumption. Moreover, integrated pest management and public awareness efforts, involving the private sector in research and research support and geographical information systems are systematically required. In addition, physicochemical, functional and organoleptic evaluation of foods in relation to consumer preferences, life-cycle analysis of environmental impacts related to processing of tropical roots and tubers, and optimized process for reducing the anti-nutrients in tropical roots and tubers are some of the areas that need proper attention and implementation. These aspects need to be designed to provide millions of small-scale farmers with the tools, technologies and solutions that could help to transform various tropical roots and tubers into food security crops, foreign exchange earners and vehicles for economic development.
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