Evaluation of functional and pasting properties of instant pounded yam/plantain flour

Plantain (Musa paradisiaca) is an important staple crop that contributes to the calories and subsistence economies in Africa. They are good sources of carbohydrate, (Marriott et.al., 1981). Plantain cultivation is attractive to farmers due to low labour requirements for production compared with cassava, maize, rice and yam (Marriott and Lancaster, 1983). Musa paradisiaca are important starchy staple and commercial crop in West and Central Africa where 50% of the world plantain crop is produced.1 In Nigeria, plantains and bananas are both important staples and are sources of income for subsistence farm families. There has been increasing trend towards large scale production of the crop.2 They contribute significantly to food security and provide more than 25% and 10% of the daily intake of carbohydrate and calories, respectively, for more than 70 million people in sub Saharan Africa.3 In Nigeria, plantain production was estimated at 2,722.000 metric tons in 2009, with an average consumption level of 190 kg/person/year (FAO, 2011). However about 3560% postharvest loss was reported.4 This means that these surpluses have to be exported or processed (Dankye et al., 2007). Hence the need to process them into shelf stable forms that will be made available all the year round. Unripe plantain flour is generally consumed for this purpose especially to manage type 2 diabetes. Results from metabolic studies have suggested that carbohydrate with high glycemic index (a qualitative indicator of carbohydrate ability to raise blood glucose levels) increase insulin demand and heighten hyper insulinemia.5–7 Yam (Dioscorea species) is an important tropical root crop. It ranked as the fourth major root crop in the world after cassava, potatoes and sweet potatoes (Adeleke, 2010). It is also an important source of carbohydrate for many people of the Sub-Sahara region, especially in the yam zone of West Africa.8 Nigeria is the world largest producer of edible yam with D.rotundata and D. alata as the two most cultivated yam species in the country. It was reported that yam contributes more than 200 dietary calories per capital daily for more than 150 million people in West Africa and serves as an important source of income to the people (Babaleye, 2003). Yams are characterized by high moisture content, which renders the tubers more susceptible to microbial attacks and brings about high perish ability of the tubers (FOS, 2011). Nutritionally, yam constitutes a significant carbohydrate and fiber food sources. Others nutrient present in yam are caloric proteins, minerals and vitamins. The crop is important in household food security, diet diversification, employment and income generation