Moisture Sorption Characteristics as Influenced by Application of Hurdles in Dambu-nama Production

Moisture transfer characteristics of dambu-nama (DN) as influenced by addition of citric acid, salt and sugar as hurdles were investigated. Four products comprising DN with 0.1% citric acid + 2% salt and 2% sugar (DNC0.1); DN+ 0.2% citric + 2% salt + 2% sugar (DNC0.2); DN + 0.3% citric acid +2% salt + 2% sugar (DNC0.3) and a control DN without citric acid , salt or sugar (DNC0) were produced and subjected to moisture sorption studies at different temperatures (30, 40, 50 and 60oC) and relative humidities of(10-96%). Incorporation of the hurdles into dambu-nama resulted in increase in monolayer moisture contents, surface areas, net isoteric heats and entropy of sorption. The isotherms obtained were best described by the Henderson model followed by the GAB and Oswin models. The hurdles also resulted to a J-shaped isotherm instead of the sigmoidal isotherm shape.