Microwave Vacuum Drying on Fruit: A Review

Abstract

Fruit is very perishable in the storage process and has short of shelf-life. To extend the shelf life, fruits need preservation process. Drying is generally acknowledged as a cost-effective and commonly used technique for preserving food by reducing post-harvest losses. The major challenge of drying fresh foods and agricultural products is to reduce the moisture content to an absolute minimum while preserving quality characteristics such as colour, texture, chemical components, and shrinkage. The vacuum drying technique has been explored as a possible method for generating high-quality dried food items such as fruits, vegetables, and grains. Microwave vacuum drying is a method that adopts the benefits of microwave drying and vacuum drying, especially enhancing energy efficiency in conjunction with product quality. This article reviews several studies on fruit drying using microwave vacuum drying, including cranberry, apple, dragon fruit, strawberry, Saskatoon berry, and pomegranate. Studies show that drying using microwave vacuum drying saves drying time many times over than conventional drying. The microwave vacuum drying technique can reduce undesired sensory transitions and nutrient loss caused by longer drying times or high surface temperatures. The use of microwave vacuum drying resulted in dried fruit similar to freeze-drying which did not significantly affect the color of the fruit and the phenolic content of the fruit.

Applied insight: studying reducing the carbon footprint of the drying process and its environmental impact and financial return

“…On the other hand, modern drying methods such as microwave, vacuum, infrared, and freeze drying lead to higher quality but consume a lot of energy. Although traditional open-sun drying does not consume any energy, it has many disadvantages such as food loss and a sharp decrease in quality (Vadivambal and Jayas et al, 2010;Dak and Pareek, 2014;Zielinska et al, 2015;Belwal et al, 2022;Wardhani et al, 2022;Ibrahim et al, 2023a). Solar drying systems, whether they depend solely on solar energy or are self-controlled hybrid drying systems, can achieve a significant reduction in CO 2 emissions as a result of a considerable reduction in the traditional energy consumed.…”

Role of Food Microwave Drying in Hybrid Drying Technology

“…The design is cost-effective and efficient for thin-layer products. The basic schematic representation of the design is represented in Figure 3 [31,32]. With samples having multiple layers, the design is challenging as drying duration increases due to the long time taken by microwaves to penetrate the layers causing [31,32].…”