Quality changes in cocoyam flours during storage
Abstract Cocoyam tubers were subjected to two processing methods (fermentation and parboiling) and milled into flour. The samples were stored at 25°C, 35°C, and 45°C and analyzed at 2 weeks interval for 8 weeks for their nutritional, functional, and pasting properties. Data obtained were subjected to multiple analysis of variance. Storage period and its interactive effect with the processing methods had significant (P < 0.05) effects on all the nutritional composition of the flour except for the fat content. Water absorption index, wettability, and bulk density ranged from 1.94–2.72%, 25.30–135.50 sec, and 0.48–0.71 g/cm3, respectively. The entire pasting properties were significantly affected by the storage period while the interaction between storage temperature, processing methods, and storage period affected all the pasting properties except the peak time, peak, and breakdown viscosity. This study showed that processing methods storage periods and storage temperatures produced cocoyam flour with different quality characteristics.
Extending the use of an underutilised tuber I: Physicochemical and pasting properties of cocoyam (Xanthosoma sagittifolium) flour and its suitability for making biscuits
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.
Isolation and Characterization of Starch from Moth Bean
The dry seeds contained 47.9% starch. The starch was isolated from seeds using cold water, hot water and alkali solution (NaOH, 1.5%) as extractant with 28.1, 32.8 and 29.9%, recovery respectively. The purified starch contained 0.06% nitrogen, 0.09% ash, and 0.16% lipids. The isolated starch contained 27% amylose with 4.0%-damaged starch. Water and fat absorption capacity and gelatinization temperature of isolated starch were 80.2%, 72.5% and 66.5 0