Effect of temperature treatment on the chemical composition of pounded white yam during storage

The effects of various temperature treatments on the chemical composition of pounded white yam (Dioscorea rotundata) during storage were studied. Temperature treatments employed were refrigerating at 4±1°C, freezing at −18±2°C and sterilization at 121°C for 15 min before storing at ambient temperature. The rates of chemical changes of untreated and treated pounded yam samples were affected by the preservation method adopted and time of storage, with the untreated ones quickly becoming staled. Parameters examined were the pH values, titratable acidity, solid and moisture contents, concentration of crude protein, amount of free reducing sugars, concentration of total available carbohydrates, amount of ether-extractable fat, fibre and ash contents. At the end of the storage period (8 days), chemical components of the untreated yams statistically differed from those of the fresh pounded yam while the treated samples were not statistically different in chemical composition from the fresh ones