Sensory Evaluation of Dawa Dawa Produced By the Traditional Fermentation of African Yam Bean (Sphenostylis Stenocarpa Harms) Seeds

Dawa dawa condiment was produced by traditional fermentation of African yam bean and soybean seeds. Processed substrates were incubated for 72 hr at room temperature in earthen pots lined with washed fresh banana leaves. Samples of African yam bean dawa dawa (AYBD) were comparatively evaluated with African locust bean dawa dawa (ALBD) sample and two types of soybean dawa dawa samples that were prepared following the procedures used by rural women in Kaduna State (KAFD) and Benue State (BEND). The sensory parameters measured were appearance, aroma, taste, and overall acceptability. KAFD was most significantly (p = 0.05) preferred in appearance and taste with scores of 6.4 and of 8.3 respectively. This was followed by AYBD, ALBD and BEND samples, respectively. The panelists highly and equally accepted all four types. The acceptability scores were 7.3, 7.4, 7.1, and 7.3 for ALBD, BEND, KAFD, and AYBD, respectively. Freshness of AYBD samples were lost after 3 days under refrigeration condition (4±2C) but all the sun-dried condiment samples were preserved for at least 6 months at room temperature (29± 2 C). @ JASEM . The stable diet among low-income groups in tropical Africa is usually a mixture of cereals or starchy foods and grain legumes. Sometime other protein-rich seeds are often included. The legumes and protein-rich seeds are added as supplement to high protein foods of animal origin, which are too expensive for the majority of the low-income earners. In Nigeria, the most popularly consumed protein-rich foods include cowpea (Vigna unguiculata), groundnut (Arachis hypogea), melon (Citrullus vulgaris), African oil bean (Pentaclethra macrophylla), and African locust bean (Parkia biglobosa). The majority of these legumes are cultivated in the Guinea savanna ecological zone. The African yam bean (Sphenostylis stenocarpa) which is well adapted to lowland tropical agro-ecosystems is not as popular as the different varieties of cowpea that are sold in the local markets and is consumed only when the prices of other legumes are prohibitive (Nwokolo 1987). Nutritionally, African yam bean (AYB) is reported to have a total seed protein of 19 to 29% (Ezueh 1984, Nwokolo 1987, Ofuya et al. 1991). The crop is not extensively utilized due to its characteristic hard-to-cook phenomenon. Recent increase in the cost of domestic cooking fuel further limits its use in the preparation of meals. Efforts aimed at providing alternative methods of utilization of the yam bean have resulted in the development of a cheese-like food (Ofuya et al., 1991), tempeh (Njoku et al., 1991), and AYB flour (Eke and Akobundu, 1993, Ene-Obong and Obizoba 1996). Some of these products may have limited use in Nigeria e.g. tempeh which is traditionally an oriental food. In this study, African yam bean seeds were fermented to produce an indigenous dawa dawa condiment and its sensory characteristics compared with that of dawa dawa produced from African locust bean and soybean seeds. Indigenously fermented condiments and foods such as dawa dawa, ogiri, and ugba are more widely used and sold. MATERIALS AND METHODS Source of legume seeds: Dry seed samples of soybean var. Malayan and AYB var. light grey, were purchased at a local market in Port Harcourt, packaged in polyethylene bags during purchase and stored at room temperature until needed. Processing of legume seeds: Twenty-five grams of each seed lot was hand sorted to remove stones and debris. Each type of legume seeds was processed by four different methods. Fig. 1 shows the four methods used in the processing of soybean seeds to produce the processed substrate. Methods 3 and 4 of Fig. 1 are the methods used by rural women from Benue State, and Kaduna State, respectively. Flow diagram for the processing of the AYB samples is shown in Fig. 2. Four different methods were also used to process the AYB seed samples prior to fermentation. Fermentation: The processed substrates were fermented using the traditional procedure described by Popoola and Akueshi (1985), which is outlined in Fig. 3. Processed substrates were transferred to washed earthen pots previously lined with a layer of washed, fresh banana (Musa sapientum L) leaves. Another layer of washed, fresh banana leaf was used to cover the substrate after which each pot was covered with an earthen lid. Substrate preparation and fermentation activities were carried out under rural domestic conditions using the facilities of a Benue State dawa dawa producer. J. Appl. Sci. Environ. Mgt. 2001