Concurrent Osmotic Dehydration and Vacuum Drying of Kiwi Fruit (Actinidia Deliciosa cv. Hayward) Under Far Infrared Radiation: Process Optimization, Kinetics and Quality Assessment

摘要

A novel dehydration protocol for Kiwi fruit (KF) involving simultaneous osmotic dehydration (OD) and vacuum drying (VD) viz. ODVD under far-infrared (FIR) radiation has been developed. This is the first report for OD of KF using fructose as osmotic solution. The ODVD process had been optimized using Taguchi orthogonal design to obtain KF with minimum moisture content in minimum time. Dehydrated KF with 4.70% (w/w) moisture content was produced in 100 min ODVD time at 50 degrees B, 40 degrees C radiator temperature and 20 mbar chamber pressures. The optimally dehydrated KF demonstrated a significant increase in the ascorbic acid content (16.60%), total phenolic content (13.09%), total flavonoid content (21.01%) and radical scavenging activity (5.85%). At optimal condition, Newton's drying model could best represent the dehydration kinetics. The high moisture diffusivity viz. 9.78 x 10(-10) m(2)/s and low activation energy viz. 10.78 kJ/mol computed through Fick's law in ODVD indicated a fast and energy-efficient process.