Influence of ultrasound and vacuum assisted drying on papaya quality parameters

The aim of this study was to evaluate the combination of ultrasound and vacuum on papaya drying kinetics and some quality parameters. Drying was performed at 60 degrees C and four techniques were used: ultrasound and vacuum assisted drying (USVD), vacuum drying (VD), ultrasound assisted drying (USD) and control (without ultrasound and vacuum) drying (CD). Fresh and dried samples were evaluated in terms of color, texture, total carotenoid and ascorbic acid contents. USVD papaya had lower processing time, requiring 270 min to reach the dynamic equilibrium condition, while CD papaya required 450 min. The samples that presented the lowest loss of ascorbic acid (41.3%) were those dried with the aid of ultrasound and vacuum, while USD samples showed lower carotenoid loss after processing (9.7%). All dried samples had a reduced luminosity and yellow color and an increase in red tone. In relation to texture, CD sample had the highest hardness value, while USVD dried sample presented the lowest value. Ultrasonic treatment accelerated the vacuum drying process for papaya and minimized the loss of the bioactive compounds studied and products' color.