Comprehensive Evaluation of Soaking-Induced Changes in Wild Cocoyam (Caladium bicolor) Flour Quality

Wild cocoyam (Caladium bicolor) is an underutilized tuber with potential for conversion into flour, but its food application is constrained by limited processing information and the presence of anti-nutritional constituents. This study comprehensively evaluated the effect of soaking duration on the proximate composition, anti-nutritional factors, functional properties and pasting characteristics of wild cocoyam flour. Tubers were processed without soaking and after soaking for 6, 8, 10 and 12 h. The resulting samples were dried, milled and analyzed using standard food-analysis procedures. Soaking duration significantly modified the proximate composition of the flour. Moisture increased from 6.82% in the un-soaked control to 9.34% after 12 h, while protein increased from 6.95 % to 8.44 %. Fat, crude fibre and carbohydrate decreased over the soaking period. Soaking also resulted in marked reductions in anti-nutritional factors. Tannin decreased from 5.18mg/100g to 0.22 mg/100 g, phytate from 9.24 mg/100g to 4.24 mg/100 g, saponin from 11.15mg/100g to 4.35 mg/100 g and trypsin inhibitor from 3.02 TIU/g to 1.06 TIU/g between the un-soaked control and 12-h treatment. Functional properties were also affected, with bulk density decreasing while water absorption capacity, swelling index, solubility and gelation capacity generally increased with soaking duration. Pasting properties showed progressive increases in peak, trough, breakdown, final and setback viscosities, accompanied by reductions in peak time and pasting temperature. The findings demonstrate that soaking substantially modifies the nutritional, anti-nutritional and technological characteristics of wild cocoyam flour and provides a potentially useful pretreatment for value addition and food-product development.