Development of methods for making high quality yam flour

Abstract

Five popular local Yam varieties were randomly selected for setting the parameters for processing yam into High Quality Yam Flour (HQYF). The varieties selected were Poria, Ponjo, Lariboko, Afase and Asana - all of which are Dioscorea rotundata species. The Asana variety was randomly selected and processed using five (5) different processing methods. The results indicated that the best of the five methods was the one which involved the dipping of the Yams in metabisulphite solution followed by blanching and drying. This method was found to be suitable for preparing HQYF from all five varieties of yams assessed, since it did not impact negatively on the quality of the flour. It was also found out that drying yams at temperatures of 550( -700( and drying times of 4.5-6.5 hrs produced flour for which the physico-chemical,pasting and nutritional characteristics were not compromised. After six months storage of the flour in two types of packaging material, the physico-chemical characteristics of HQYF were not significantly different from the freshly prepared flour. However the transparent plastic containers were found to preserve the quality of the product better than the polyethylene pouches. The sensory quality of products made from the HQYF was also found to be very acceptable. HQYF from Pona and Ponjo were however much preferred for preparation of fufu than Afase, Lariboko and Asana. HQYF from all the varieties were equally liked for the preparation of biscuits