Effect of micronisation of pre-conditioned cowpeas on cooking time and sensory properties of cooked cowpeas


Correspondence to: Henriette L de Kock, Department of Food Science, University of Pretoria, Private Bag X20, Hatfield, Pretoria 0028, South Africa. E-mail: riette.dekock@up.ac.za


BACKGROUND: Cowpea is mostly utilised as cooked whole seeds. This is often achieved only after boiling for up to 2 h, resulting in high energy consumption and a long time for food preparation. Micronisation of pre-conditioned cowpeas reduces their cooking time. Micronisation changes the physicochemical properties of cowpea seeds, which may affect the sensory properties of cooked cowpeas. Consumer acceptance and utilisation of micronised cowpeas depend on their sensory properties. Micronised and unmicronised samples of Blackeye, Bechuana white, Glenda and Dr Saunders cowpeas were subjected to cooking time, descriptive sensory and colour analyses.

RESULTS: Micronisation significantly reduced cowpea cooking time by 28–49%. There were significant (P < 0.05) increases in roasted aroma and flavour, mushy texture and splitting in all micronised samples. Bechuana white was more mushy and split than others. There were significant decreases in firmness, mealiness and coarseness after micronisation for all cowpea types. Micronised cowpeas were darker (lower L* values) than unmicronised cooked cowpeas. Darkening was more evident in light-coloured than dark-coloured cowpeas.

CONCLUSION: Micronisation reduces cowpea cooking time but also affects sensory properties of cowpeas such as introducing roasted flavours that may not be familiar to consumers. This might have an influence on consumer acceptance of micronised cowpeas. © 2012 Society of Chemical Industry