Abstract

Cocoyam is one of the important root food crops especially among the low income earners in Nigeria. However, the utilisation options of cocoyam are mainly limited to direct consumption as whole boiled or pounded tuber only, thus making it an underutilised crop. Physicochemical and pasting properties of cocoyam flour, its suitability and acceptability in biscuit making were determined. Red and white cocoyam varieties were processed into flour by sun-drying method. The physicochemical and pasting properties were compared with that of commercial wheat flour (CWF). Cocoyam flour and wheat flour blend in the ratio 10:90, 20:80, 50:50 and 100% were used to prepare biscuits and sensory evaluation was conducted. Blanched cocoyam flours had significantly higher (p<0.05) starch and amylose content than the unblanched flours: 21.36 and 21.87% starch; 44.35 and 44.20% amylose, blanched white cocoyam flour (Bl-WCF) and blanched red cocoyam flour (Bl-RCF), respectively; 21.12 and 15.56% starch and 39.36 and 43.39% amylose, unblanched white cocoyam flour (U-WCF) and unblanched red cocoyam flour (U-RCF), respectively. Peak viscosity was significantly higher (p<0.05) in blanched flours (262.79RVU and 267.58RVU, Bl-WCF and Bl-RCF, respectively) than in unblanched flours and CWF (161.79RVU, 200.58RVU and 145.54RVU, U-WCF, U-RCF and CWF, respectively). Sensory evaluation showed that biscuits made from two flour blends had high acceptability especially at 10% substitution level.

Key words: Cocoyam flour, physicochemical properties, pasting properties, biscuits, sensory evaluation.