Chemical, functional and sensory properties of processed African yam beans (Sphenostylis stenocarpa) and cowpeas (Vigna unguiculata)

Abstract

Two legumes, African yam beans (Sphenostylis stenocarpa) and cowpeas (Vigna unguiculata), were processed into akara, moimoi and porridge then analyzed along with the raw samples for chemical, functional and sensory properties. Results showed that all the samples (raw or processed) had similar and high crude protein content with an average of 20.7%. The cowpea and African yam bean porridges had the highest (22.9%) and the lowest (19.9%) crude protein, respectively, which showed that the two legumes are very good sources of protein. Moimoi made from African yam beans had lower gelation capacity (19.4 w/v), higher water absorption capacity (68.0 ml/g), and lower oil absorption capacity (35.9 ml/g) than that made from cowpeas with 23.6 w/v, 54.0 ml/g and 41.0 ml/g, respectively. Similarly akara made from African yam beans had a higher gelation capacity of 34.5 w/v, water absorption capacity of 71.0 ml/g and a lower oil absorption capacity of 60.0 ml/g compared to that made from cowpeas (30.6 w/v, 57.0 ml/g and 62.02 ml/g respectively). Sensory evaluation showed that moimoi and akara made from African yam beans were not significantly different (p0.05) in color, flavor, texture and overall acceptability compared to those made from cowpeas indicating that African yam beans could be very useful in the preparation of moimoi and akara. In general, processing into akara and moimoi improved the oil absorption capacity of the African yam beans. The improved capacity to bind fat would be useful in ground meat formulations such as sausage in addition to the usefulness in making moimoi and akara.