**6. Solar drying of various food substances**

In this section, solar drying of various food substances such as vegetables, fruits, marine products, and others, as shown in **Figure 7**, was elaborately discussed.

#### **6.1 Vegetables**

This section discusses the performance of different solar dryers for drying various vegetables, including Bottle gourd, Carrot, Potato, Ivy gourd, and Onion. The summary of the same is presented in **Table 4**.


#### **Table 3.** *Different thin-layer models for drying.*

**Figure 7.** *List of various food substances.*

### *6.1.1 Bottle gourd*

K.A. Shinde et al. evaluated the drying characteristics of steam-blanched and nonblanched bottle gourd samples. A tray dryer with forced convection and hot air was used to carry out the drying process. The samples were pulverized for analysis, and their initial moisture content was 0.04 kg water per kg dry matter. The study aimed to determine the effect of blanching on the drying efficiency and qualitative parameters of bottle gourd. The samples are pulverized for examination, and the research intends to determine the effect of blanching on the drying efficiency and qualitative features of bottle gourd [33].

Kukadiya Vishal et al. investigated using a fluidized bed dryer with forced convection for drying samples of various forms; specifically slab shapes 10 10 3 mm, 10 10 5 mm, and 10 10 7 mm. The study compared the effects of various temperatures on quality measures, including water activity and color. According to the data, the sample with dimensions of 10 10 3 mm and a temperature of 70°C has the optimum quality in terms of water activity. Furthermore, the sample with dimensions of 10 10 5 mm at 60°C exhibits outstanding color quality. The importance of shape and temperature selection in optimizing the quality features of dried items using a fluidized bed dryer was underlined in this study [34].
