From Past Insights to Future Pathways: A Process-Engineering Perspective on Refractance Window Drying

Abstract

The proactive drying technology called refractance window drying (RWD) has the ability to convert fragmented slices of fruits and vegetables, liquid food, pulp and other biomaterials into edible leathers, flakes, or powders. The aim of this review is to systematically analyze RWD research using quantitative analysis and qualitative analysis to identify trends and research gaps. This systematic review integrates quantitative and qualitative approaches, wherein the quantitative component was conducted using R Studio and VOSviewer software to perform bibliometric mapping and network visualization while the qualitative component was based on an in-depth true case study to provide practical and contextual insights. For the quantitative analysis, the Scopus database was used to retrieve publications from 2014 to 2024, based on the key search term “Refractance Window Drying” appearing in the article titles. Quantitative analysis was conducted on 141 publications sourced from 63 different sources. Finding of the quantitative analysis revealed that the 28.73% yearly growth rate of publications; journal ‘Drying Technology’ is the dominant journal and India prominently leading at 96 publications in this field. Qualitative analysis findings revealed that in the last ten years research has primarily focused on mathematical modeling and comparison. Based on quantitative and qualitative analysis, this review unveils some key research gaps in the RWD field, which includes the limited advancements in design and hybridization, insufficient application of advanced modeling tools, underexplored membrane material science, and limited food safety assessment of RW dried products, particularly concerning potential microplastic migration.