INFLUENCE OF ULTRASOUND ASSISTED OSMOTIC DEHYDRATION PRETREATMENT ON CONVECTIVE DRYING OF PINEAPPLE

JEFFERSON LUIZ GOMES CORRÊA; MERCEDES CAROLINA RASIA; JOSE VICENTE GARCIA-PEREZ; ANTONIO MULET; JUAN ANDRES CÁRCEL

Maceió

Congreso; XXXVI Congresso Brasileiro de Sistemas Particulados (ENEMP 2013); 2013

UNIVERSIDADE FEDERAL DE ALAGOAS

Osmotic dehydration (OD) is a partial dehydration process. It is currently used as a hot air drying pretreatment because it reduces energy consumption and product heat damage. The application of high intensity ultrasound during OD could improve the mass transport by producing effects such as cavitation or sponge effect. For this purpose, the influence of OD, without and with ultrasound application (1500 W, 40kHz), on convective drying of pineapple slices (2 cm diameter, 0.5 cm thickness) was studied. The OD was carried out in a 40 °Brix sucrose solution for 20 and 40 min at 25 °C. After, the samples were convective dried (40 °C, 1 m s-1) until active a final moisture content of 0.19 kg H20 kg dry matter-1. The mass of the samples was monitored each 5 minutes. The results showed that the osmotic pretreatment reduced the drying time. The pretreatment during 20 min carried out to higher time reduction than the one performed during 40 min. Ultrasound application during the pretreatment reduced drying time. From modeling of air drying kinetics, the influence of osmotic dehydration, with and without ultrasound application, was quantified.