Proximate and some physicochemical properties of yam flour as a function of yam tuber storage methods

Abstract

This paper reports the proximate and some physicochemical properties of yam flour and yam tuber storage methods with a view to identifying the best storage method for yams. Two varieties of yam (D. cayenensis and D. alata) were processed directly into flour immediately after harvest and after storage in pits and barns specially created for this particular study for between 1 and 3 months using a laboratory hammer mill. The proximate and functional properties of flours produced from the stored yam tubers were determined by standard methods. The protein content for D. cayenensis flour ranged from 1.04 to 1.26 for tubers stored in pits while it ranged from 1.08 to 1.26 for tubers stored in barns. The results obtained were significantly different at P › 0.05 except for those of one storage for the two storage methods and varieties. Tubers stored using the pit method for one (1) and two (2) months were not significantly different for all parameters and showed that protein values are a function of storage method and period.

The fibre content of the two varieties are very low, which make the yam flour suitable for noodle production. Also, there was a general decrease in the moisture content for the two varieties, though not significantly different. Starch content for D. cayenensis ranged from 68.86 to 71.08 and from 69.94 to 72.07 for D. alata..

The swelling properties of D. cayenensis were not different from that of D. alata. Swelling properties ranged from 8.75 to 9.34 (pit) and 8.75 to 9.11 (barn) for D. alata and from 8.47 to 9.13 (pit) and 8.75 to 9.31 (barn) for D. cayenensis. Solubility also followed the same trend as swelling properties with significant differences in values obtained.

Generally, storage methods and periods have significant effects on the properties of yam flour produced from D. cayenensis and D. alata.

Keywords: D. cayenensis. D. alata, Yam flour, Storage method and Storage period