ABSTRACT
 In this study, different methods of extraction for further comprehension of the volatiles composition of fresh guava (Psidium guajava L.) Palmira ICA-1 was used. Extraction methods like liquid-liquid extraction (L-L), simultaneous distillation-solvent extraction (SDE), headspace-solid phase microextraction (HS-SPME) and supercritical fluid extraction (SFE) were used. It was shown the differences and similarities of the volatile composition related to the used method. The most representative compounds found by L-L, SDE and HS-SPME were esters, aldehydes and alcohols, while by SFE the hydrocarbons were predominant. A total of 134 compounds were identified by the different extraction methods. The flavor contribution of the volatiles isolated by SDE was calculated by the ratio of concentration of the compound and its flavor threshold, taking into account the effect of temperature during the extraction procedure as well as the pH influence over the aroma composition. A total of 38 volatile constituents were identified as bonded to glycosides. 
 On the other side, a study about the hydrodynamic mechanism (HDM) of the osmotic dehydration with and without vacuum pulse was carried out. Major losses of water occurred with a treatment at 50 °C and with osmotic dissolution at 50 and 40 °Brix. Major transfer rate of the solutes was observed at 40 and 50 °C with pulsing vacuum. The significant effect of temperature, time of treatment, and the osmotic dissolution concentration on the kinetic of water loss, recovering of solutes and the evolution of the volatile composition in the osmodehydrated product was demonstrated. In general, the major losses of volatiles occurred at 50 °C, while the minor were at 30 and 40 °C up to 2 h with osmotic dissolution at 30 and 40 °Brix. Esters were the compounds which suffered higher losses during osmotic dehydration processes at atmospheric pressure and with vacuum pulse.