Abstract
Food products tend to equilibrate with the environment when they are stored. The moisture in food sample and effect of temperature determines the susceptibility of physicochemical properties of foods to changes. This phenomenon has implications on microbial and chemical deteriorations with consequential effect on quality of the foods. In an attempt to ensure that yam flour is durable, an analysis of moisture sorption data in a previous study was undertaken to determine adequate storage environment and moisture content at which the flour will retain desirable qualities under practical storage conditions. For yam flour to be durable in storage structures that are exposed to a tropical situation with temperature range of 27 to 40oC, and water activity of 0.10 to 0.80, respectively this study determined water activity range of 0.24 to 0.45 for yam flour at moisture contents of between 6.64 and 8.32 (% dry basis) in a situation of adsorption, and a range of 6.64 to 8.10 (% dry basis) when moisture desorbs in the yam flour. The monolayer moisture contents determined were 3.83 to 4.56 (% dry basis) for adsorption, and 3.92 to 4.76 (% dry basis) for desorption over the range of temperature where the sorption phenomena was investigated. The information can benefit stakeholders in food crop processing sector towards availability of high quality flour as a food ingredient, and for industrial utilisation. This has high tendency to improve customer’s satisfaction and invariably provoke growth in the profit margin of the food processing sector.
Keywords: yam flour, sorption, storage, stability, durability