Effects of Decortication Temperature on the Functional Properties of Cowpea (Vigna unguiculata) Flour and Sensory Properties of Moi-Moi

Abstract

The effects of decortication temperature on the functional and sensory properties of the cowpea flour (Vigna unguiculata) and steam flour paste were studied. Cowpea seeds were soaked at different temperatures (20^oC, 40^oC, 60^oC, 80^oC and 100^oC) prior to decortication. The functional properties of the cowpea flour, pasting properties of the flour paste and sensory properties of the steamed cowpea paste (moi-moi) were analysed using the standard methods. The results obtained showed that the effects of decortication on the functional properties of cowpea flour were significantly different (p < 0.05) except its pH which was not significantly different (p > 0.05). Flour sample at decortication temperature of 40^oC showed the least boiling and gelation temperature, and also the highest value in foaming capacity, water and oil absorption capacities. Significant differences (p < 0.05) existed in the pasting properties of the flour paste. Samples at decortication temperature of 40^oC and 27°C showed respectively the least and highest values of peak, trough and breakdown viscosities. The sensory properties among the steamed paste samples also showed significant difference (p < 0.05). The sample at decortication temperature of 40^oC had the highest values in the sensory parameters while been comparable to samples at decortication temperatures of 60^oC (moisture), 80^oC and 100^oC (flavour and overall acceptability), and 27^oC (overall acceptability). It was concluded from the results, that decortication temperature of cowpea for moi-moi production is more suitable at temperature 40^oC.

Keywords: Cowpea, decortication temperature; functional, pasting and sensory properties.