Sorption Isotherms of Some Nigerian Dry Condiment Powders

摘要

The moisture sorption isotherms of dehydrated flours of four commonly consumed Nigerian condiments (namely, ugba, okpeye, ogiri and iru) were determined. The dry milled products were kept at three separate temperatures (10, 30 and 40°C) and at four different relative humilities using saturated salt solutions (RH 20, 30, 50, and 70%) for a period of 21 days. Both the initial and equilibrium moisture contents were determined on the products and the data obtained were used to construct moisture sorption isotherm curves. The results reveal that higher storage temperature gave lower sorption capacities for the condiment powders. Also, the rate of moisture absorption increased at the monolayer at all the storage temperatures considered. At ambient and higher storage temperatures, ogiri had the relatively longest shelf life, followed by okpeye, then iru and finally ugba.