ISOTERMAS DE DESORCION DE HUMEDAD EN PITAHAYA AMARILLA (Selenicereus megalanthus)

moisture desorption isotherms for yellow pitahaya fruits were studied at 15, 25, and 35°c using the gravimetric method for a 0.111-0.901 water activity range. experimental values were adjusted by using the gab, henderson, smith, oswin y chung y fost models. the isosteric heat of adsorption (qst) was determined using the clausius-clapeyron equation. the results showed that yellow pitahaya fruits exhibit type iii adsorption isotherms and that the equilibrium moisture content (emc) is temperature-dependent. for the same water activity value, the emc decreased when temperature increased. the gab model presented the best fit to the experimental values. the qst dropped from 61.43 a 45.11 kj/mol when the emc increased from 0.08 to 0.56 g water/g dry matter, respectively.