73G-26 |
Texture profile, nutritional and physicochemical characteristics of some cowpea varieties commonly consumed in West Africa |
E. O. SAKYI-DAWSON1, C. Amankwaah2, J. Ayin2, and S. K. Sefa-Dedeh2. (1) Department of Nutrition and Food Science, University of Ghana, P. O. Box LG 134, Legon, Ghana, (2) Ghana Cowpeas are an important part of the diet of West Africans and contribute significantly to improving the protein intake in the diet. In addition to several indigenous varieties, many new varieties are being introduced into the system yearly through breeding programs. Breeding programs generally focus on improving the yield and/or pest or disease resistance of the cowpea varieties. These new varieties invariably have differences in their sensory and other quality characteristics which affect their utilisation. From a utilisation viewpoint it is important to study these quality characteristics in order to know the suitability of the different varieties for different food uses. The objective was characterisation of the textural properties, chemical and physicochemical characteristics of cowpeas in order to assess how best they can be utilised. The dehulling efficiency, lowest gelation concentration (LGC), and functionality of four varieties of cowpeas (Tamale, Check, Niger and Togo) were determined. Chemical indices studied were tannic acid, protein, starch and sugar. Individual sugars were determined by HPLC. Sensory and instrumental methods were used to characterise the texture of the cowpeas. Standard rating scales were developed using Ghanaian foods and a comparative texture profile ballot was developed. Dehulling efficiency ranged from 74% (Check) to 95% (Niger). Protein varied between 19% (Niger) to 26% (Check) and starch ranged from 15% (Check) to 42% (Togo). Togo also had the highest LGC of 20%. Tannic acid content was highest in Check, a red colored variety. Stachyose was approximately 4.5g/100g in all the varieties whilst sucrose ranged from 1.2g/100g (Check) to 2.5g/100g (Togo). Panelists used fifteen terms to describe various textural characteristics of the cowpeas. The most frequently used terms were soft, moist, mealy and smooth. Both sensory and instrumental hardness were in the order Check>Tamale>Togo>Niger. The differences that exist in the cowpeas can be exploited for different food applications.
Session 73G, Sensory Evaluation
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