Determination of microwave drying and rehydration kinetics of green peppers with the bioactive and textural properties

Abstract

The aim of this study was to determine the effect of microwaves on drying and rehydration kinetics of green pepper varieties (sweet, green, and bell) and the bioactive and textural properties of dried and rehydrated peppers. Drying was performed at 90, 180, and 90 + 180 W and dried peppers were rehydrated at 25, 50, and 70 C.The best drying fits were obtained using the equations of both Sigmoid and Hii et al.for drying, and two term exponential decay was the most appropriate model for rehydration. The lowest and highest final rehydration ratio values were obtained for the peppers dried at 180 and 90 W, respectively at each temperature and pepper variety. Among peppers, bell pepper showed the lowest color change (ΔE) and it was the most potent to recover initial color in rehydration. Peppers had softer texture in both drying and rehydration treatment. Total phenolic content of peppers was reduced around 56-65% compared to the fresh pepper by drying and this decrement was reached up to 87% in rehydrated peppers. Results showed that drying at 180 W and rehydration at 70 C provided faster drying and rehydration as well maintained the quality characteristics of green peppers. | INTRODUCTIONSweet, green, and bell peppers, which are different varieties of green peppers (Capsicum annuum L.), have been used either fresh or dried in food industries. However, their long-term storage is not possible in fresh form due to high moisture content around 95%; therefore, drying can be applied for using peppers during the off-season with

Assessment of the Effects of Roasting, Contact Grilling, Microwave Processing, and Steaming on the Functional Characteristics of Bell Pepper (Capsicum annuum L.)

“…Similar results were obtained by Darıcı et al in 2021 [ 51 ] (ΔE values of 13.97) for green bell peppers that were microwave-dried. On the other hand, in a study conducted by Eyarkai et al in 2016 [ 52 ], it was shown that the blanching process for vegetables such as green peas, eggplant, and green bell peppers resulted in a reduction of all CIE color coordinates (L, a, b) in these raw materials, which was associated with a weakening of color as a result of the leaching and migration of color substances into hot water [ 53 ].…”

“…On the other hand, in 2021 Darici et al [ 51 ] reported that the microwave drying of green bell peppers (180 W) resulted in a decrease in L* and b* values, while a significant increase in a* values compared to fresh bell peppers was observed. This was indicated by the browning of the processed samples.…”

Effects of cutting and drying method (vacuum freezing, catalytic infrared, and hot air drying) on rehydration kinetics and physicochemical characteristics of ginger (Zingiber officinale Roscoe)

“…Cox et al (2012) found that in comparison with fresh seaweed, the total phenol content (TPC) and total flavonoid content (TFC) in rehydrated seaweed were lower. Darıcı et al (2021) also discovered that in comparison with fresh green pepper, the texture of green pepper after rehydration became softer and the TPC decreased. Therefore, it is essential to find an optimal drying method, because the drying and rehydration process will lead to changes in food texture and composition.…”

“…Darıcı et al. (2021) also discovered that in comparison with fresh green pepper, the texture of green pepper after rehydration became softer and the TPC decreased. Therefore, it is essential to find an optimal drying method, because the drying and rehydration process will lead to changes in food texture and composition.…”

Microwave‐modified xanthan gum: Alterations in steady and dynamic rheological behaviors

“…Free water possesses a much greater impact on dielectric properties than bound water. This is due to the fact that water is the major absorption factor of the energy (Darıcı et al, 2021; Kumar & Karim, 2019; Kutlu et al, 2022). Therefore, heat is produced by the movement of dipole molecules, which ultimately leads to the evaporation of water in the product.…”