The antinutritional and vitamin composition of high‐quality yam flour as affected by yam specie, pretreatment, and drying method

Fresh yams are not shelf stable due to its high susceptibility to physiological deterioration; hence, its conversion into a more stable product like flour can stimulate its industrial application as a substitute to wheat flour. The influence of yam species, pretreatment, and drying method on the antinutritional factor and vitamin composition of high‐quality yam flour (HQYF) was determined. Four different yam species were pretreated with 0.28% potassium metabisulphite for 15 min and blanching at 70°C for 15 min. The differently pretreated slices were thereafter dried with cabinet dryer at 60°C for 48 h and open sun for 3 days, then milled into flour. The flour samples were analyzed for antinutritional and vitamin contents using standard laboratory procedures. The antinutritional factors in the high‐quality yam flour were significantly (p < .05) affected by yam specie, pretreatment, and drying methods. The low level of alkaloids (0.02 mg/100 g) and phytates (13.43 mg/100 g) in the flour samples from D. rotundata in this study underscores its safety for absorption in the body when consumed/used as food formulations. The main and interactive effect of specie of specie, pretreatment, and drying methods influenced the vitamin content of the high‐quality yam flour significantly (p < 0.05). The appreciable level of vitamin C (20.87–30.91 mg/100 g) recorded in all the HQYF could indicate the product of good nutritional quality for the consumers.