Effects of hot air, vacuum infrared, and vacuum microwave dryers on the drying kinetics and quality characteristics of orange slices

Abstract

The present study aimed to dry orange slices at 50, 60, and 70 C using vacuum microwave dryer (VMD), vacuum infrared dryer (VID), and tray dryer (TD) and to compare the effects of different drying techniques on drying kinetics and product qualities. For this purpose, drying kinetics, total phenolic content, vitamin C, pH, total titratable acidity, bulk density, and color values of dried orange slices were evaluated. The VMD significantly increased the drying rates and the effective moisture diffusivities of orange slices compared with the VID and the TD. The drying times of orange slices for the VMD, the VID, and the TD at 70 C were detected as 69, 92, and 180 min, respectively. The experimental data were fitted to six thin-layer drying models with R 2 range between .929 and 1.000. The results showed that the VMD had the smallest change in total phenolic content, vitamin C, pH, total titratable acidity, bulk density, and color values (L*, a*, b*, ΔE, ΔC, and Hue) of dried orange slices, whereas the TD had the highest changing. Practical applications Drying is a common preservation technique used for the long-term durability of fruits and vegetables. This technique decreases the cost of storage, packaging, and transport of fruits and vegetables. Nevertheless, the traditional drying technique has some disadvantages, such as low energy efficiency, long process times, and a reduction in quality characteristics. The vacuum microwave dryer (VMD) and the vacuum infrared dryer (VID) have advantages such as higher drying rate, lower drying time, homogeneous temperature, high-energy efficiency, and good product quality. In the industry, the VMD and the VID can be used as an alternative to the hot air drying, making the drying process faster for the fruits and vegetables.

Effect of pulsed‐vacuum, hot‐air, infrared, and freeze‐drying on drying kinetics, energy efficiency, and physicochemical properties of Ginkgo biloba L. seed

“…This may be due to case-hardening that obstructed the moisture transfer throughout the ginkgo seeds drying process, and this attests to why it had the least drying rate (Figure 1b) amongst the heat-dried ginkgo seeds (ID, HAD, and PVD). The lowest Finally, mathematical modeling's' of the drying processes were applied to the ginkgo seeds drying process since it is essential in designing and optimizing, as they have been widely utilized to define foods' drying characteristics (Bozkir, 2020;Ertekin & Firat, 2017;Jahanbakhshi et al, 2020). The drying kinetics of ginkgo seeds were represented using three thin-layer models.…”

“…These can be solved mainly by artificial drying processes such as hotair, microwave, vacuum, infrared, and freeze-drying, which can shorten drying time, develop desirable products and increase food bioactivity Bozkir, 2020;Kaveh, Jahanbakhshi, Taghinezhad, & Abbaspour-gilandeh, 2018;Wang et al, 2020).…”

“…Besides, product quality could be low, which significantly reduces the economic benefits of farmers. These can be solved mainly by artificial drying processes such as hot‐air, microwave, vacuum, infrared, and freeze‐drying, which can shorten drying time, develop desirable products and increase food bioactivity (Abbaspour‐Gilandeh & Jahanbakhshi, 2019; Bozkir, 2020; Kaveh, Jahanbakhshi, Taghinezhad, & Abbaspour‐gilandeh, 2018; Wang et al, 2020).…”

Effects of tray drying, vacuum infrared drying, and vacuum microwave drying techniques on quality characteristics and aroma profile of orange peels

“…Lightness (L * ), redness (a * ), and yellowness (b * ) values were determinate using a colorimeter (CR-10; Konica Minolta, Japan). Total color difference (ΔE), total chroma (ΔC), and Hue angle (H ) were calculated according to Formulas (7), (8), and (9), respectively (Bozkir, 2020).…”

Effects of pretreatments on quality attributes, moisture diffusivity, and activation energy of solar dried ivy gourd

“…It was reported that the sweet potato slices treated with 0.5:1.0% KMS and citric acid at 50°C has shown optimal condition for predict drying kinetics. Bozkir (2020) used three different types of dryers, namely vacuum microwave, tray type and vacuum infrared dryers for drying orange samples at 50°C ‐70°C drying air temperature. It was observed that the Page and Logarithmic mathematical model gave better agreement with the experimental results.…”