A review on refractance window drying of fruits

Abstract

Drying of fruits is one of the preservation technique used to remove moisture from the product which results in retardation of spoilage causing microbes as well as chemical reactions. Refractance Window Drying (RWD) is an innovative and efficient drying technique that preserves the nutritional value and quality of fruits more effectively than traditional drying methods. RWD utilizes a unique heat transfer mechanism that involves conduction, convection, and radiation, enabling rapid moisture removal while maintaining the bioactive compounds in the fruit. This method is particularly advantageous for its energy efficiency, consuming 28-38% less energy compared to conventional dryers such as hot air, freeze, and spray drying. This significant reduction in energy usage not only lowers operational costs but also minimizes environmental impact. RWD has been shown to preserve vital nutrients, including vitamin C, antioxidants, and phenolic compounds, which are often degraded in other drying methods. Additionally, the shorter drying time associated with RWD helps in retaining the colour, aroma, and texture of the dried fruits, making them more appealing to consumers. The technology has been successfully applied to a variety of fruits, demonstrating superior retention of nutritional and sensory properties. Future advancements in RWD technology aim to integrate renewable energy sources, such as solar power, to enhance sustainability and further reduce the environmental footprint of the drying process. In conclusion, RWD presents a promising alternative to traditional drying methods, offering substantial benefits in terms of energy efficiency, nutritional preservation, and product quality.