A Comprehensive Review of Mechanisms, Heat Transfer Dynamics and the Hybrid Approach of Refractance Window™ Drying

Abstract

As an innovative dehydration technique that combines effectiveness, energy conservation, and preserves quality of product the Refractance Window™ (RW) drying offers a competitive substitute for conventional drying techniques like tray, vacuum, and drum drying. This comprehensive review analyzes the fundamental mechanism, heat transfer dynamics, and the novel hybrid methodologies of RW drying. Key findings emphasize the distinct mechanisms of heat transfer through thermal conduction, convection, and radiation, which enhance drying kinetics while reducing nutrient degradation and energy consumption. Furthermore, hybrid RW drying systems that integrate techniques such as infrared, osmotic, microwave, solar and ultrasound drying demonstrate enhanced performance, particularly in decreasing time for drying and enhancing drying efficiency and quality of food products. A comparative examination highlights that the hybrid approach increased the efficiency and scalability of RW drying which is better for industrial applications. RW dryers are useful for handling high-protein foodstuffs, preparing fruit leather and edible films, improving the gelling and emulsion qualities, and drying leafy vegetables or marine foods without compromising their nutritional content. Despite its benefits, difficulties like as material-specific adaptations, energy optimization, and scaling up processes remain subjects for more investigation. The majority of research on RW drying concentrates on the determining the quality of product. This study consolidates existing knowledge, patents and opens up key research gaps, delivering some practical insights for developing the design and implementation of RW drying systems.