Adsorption isotherm and heat of sorption of fresh- and osmo-oven dried plantain slices

Moisture adsorption characteristics of gingerbread, a traditional bakery product in Pardubice, Czech Republic

“…Therefore the negative temperature effect is eliminated at higher water activities. This is consistent with other foods with highsugar content such as dried plantain slices (Falade, Adetunji, & Aworh, 2003), Turkish tarhana powder (Ibanoglu, Kaya, & Kaya, 1999), African mango (Falade & Aworh, 2004) or rice based milk desert kheer (Kumar et al, 2005). On the other hand, the crossing of the isotherms has not been observed in cookies and corn snacks (Palou et al, 1997) or various cereals (Ertugay & Certel, 2000) which contain mainly complex carbohydrates rather than simple sugars.…”

“…The curve shows that the heat of adsorption decreased with increase in moisture content, initially rapidly up to 15% d.b. and later slowly, as observed in many other food systems (Aviara, Ajibola, & Oni, 2004;Falade et al, 2003;Kaymak-Ertekin & Gedik, 2004;Kumar et al, 2005;Turhan et al, 2003). The decrease in the isosteric heat with the increase in sorbed water content may be attributed to the fact that sorption initially occurred in the most active sites giving rise to the greatest interaction energy.…”

“…corresponded well to safe moisture content derived from Henderson equation. Negative values of heat of sorption at high moisture content are a direct contribution of the endothermic dissolution of sugar in the sorbed water (Falade et al, 2003;Kaymak-Ertekin & Gedik, 2004). However, the negative Q st value has no physical meanings and might be within the error of mathematical determination (Kaymak-Ertekin & Gedik, 2004).…”

Water desorption thermodynamic properties of pineapple

“…The obtained figures for these thermodynamic functions (Q st n and S d ), which have been represented vs. the pineapple moisture content in Figs. 5 and 6, respectively, are of the same order than those proposed by different authors for other food products (Mohamed et al (2005), in bitter orange leaves; Falade, Adetunji, & Aworh (2003) in fresh and osmo-dried plantain slices; Kaymak-Ertekin & Gedik (2004), in grapes, apricots, apples and potatoes;McMinn et al (2005), in starchy materials).…”

Different methods of equilibrium moisture content determination

“…The point of intersection of the sorption isotherms depend on the structure of the food material, as well as the type and distribution of sugar quantity in the material (Weisser, 1985). Similar results were reported in literature for isotherms of quince exposed to pre-treatment with ultrasonicosmotic dehydration (Noshad et al, 2013), and for the sorption isotherms of some various fruits : prickly pear (Lahsasni et al, 2003;Barroca et al, 2005), apple (Roman et al, 1982;Saravacos et al, 1986) raisins, fig, plum and apricot (Maroulis et al, 1988;Tsami et al, 1990), grape and apricot (Kaymak-Ertekin and Gedik, 2004), mango (Falade et al, 2003). …”