Refractance Window Drying: An Emerging Technology for Heat-Sensitive Food Products

As we all know the shelf of any product depends chiefly on its moisture content. Microorganisms survive and multiply mostly because of moisture content.

- Harshita Sonarthi and Supreetha. S

INTRODUCTION

So, if we have to hinder the growth of microorganisms we have to think over the existence of moisture content in the product, so either we can make available moisture content unavailable, which is possible by freezing, but it is a costintensive process other technique is by removing water by the application of heat that is drying. Drying nowadays is a prevalent technique to preserve any food product. Refractance Window-Drying (RWD) is one such novel fourth-generation drying technology that has recently gained huge attention due to its several advantages. It is employed to dry heat-sensitive products like juices and purees to retain the product colour, aroma, antioxidant compounds, and nutritional properties. In this technology, drying of product is done using thin, transparent infrared film which eventually forms a “window” for drying, it assures very lowtemperature drying with rapidity, with all modes of heat transfer. It has various advantages over other conventional drying methods like drying temperature, time, cost and energy consumption are lower in this technology, but if we talk about thermal efficiency and _ product quality it shows good results as compared to drum drying, freezedrying, spray drying, tray drying, etc., which possess their own limitations.

PRINCIPLE