Instant premix for steamed cowpea (Vigna unguiculata L. Walp) pudding: Effect of foam-mat and air-oven drying on flour and end product characteristics

Abstract

Abstract The effect of foam-mat and air oven drying on nutritional, functional, colour, rheology and microstructural properties of instant cowpea premix for production of moin-moin, a popular tropical protein-based meal, was investigated. In addition, the sensory properties of moin-moin prepared from the premixes were comparatively evaluated with traditionally produced moin-moin and the one produced from commercial cowpea flour. Foam-mat dried premix produced moin-moin of significantly higher nutritional quality than the oven-dried premix and the commercial cowpea flour. Furthermore, foam-mat dried products had higher bulk density, wettability, emulsion and foam capacity. Commercial cowpea flour had higher hydrophilicity, whereas the premixes had higher oil absorption capacities. Loss of desirable colour properties as evidenced by higher a* and b* values in oven-dried premix occurred. Pasting properties were significantly affected by drying method with the oven-dried premix having the highest tendency to retrograde and disintegrate. Microstructure of the premixes and cowpea flour showed distinct differences in their uniformity and granule size. Comparatively, moin-moin from the premixes had higher nutritional properties, but were less preferred in terms of sensory quality attributes than the one prepared conventionally and from commercial cowpea flour.