Dehydration of Malay Apple (Syzygium malaccense L.) Using Ultrasound as Pre-treatment

This work examined the influence of the ultrasonic pre-treatment prior to air drying on dehydration of jambo (Syzygium malaccense L.) also known as Malay apple. This study allowed the estimation of water loss and sugar gain during the pre-treatment and the effective water diffusivity in the air-drying process for jambo subjected to ultrasonic pre-treatment. Results showed that during the ultrasonic treatment, in distilled water, the Malay apples lost sugar, so such a pre-treatment stage can be a practical process to produce dried fruits with lower sugar content. The water effective diffusivity increased by 28.1% (best result) after application of ultrasound, which caused a reduction of about 27.3% in the total drying time.