# The Effect of Pre-Treatment on the Rehydration of Dried Apple Cube
## 1 Introduction
[34] conducted a study to correlate hydration behavior with the processing conditions of low-amylose parboiled rice, which was dried at temperatures of 40, 50 and 60 \({}^{\circ}\)C. They then examined the rehydration characteristics of parboiled rice (dehusked only) at soaking temperatures of 30, 40 and 50 \({}^{\circ}\)C for up to 3 h at 30 min intervals, subsequently determining the equilibrium moisture content during rehydration. The obtained data were tested against three hydration equations: Peleg, exponential, and Weibull. The results indicated that the Weibull model provided a better fit than the exponential model and [PERSON]'s equation. The authors also described water transfer into the dehusked grains using [PERSON]'s diffusion model and calculated the moisture diffusivity, which ranged from 1.06 to 4 \(\times\) 10\({}^{-11}\) m\({}^{2}\)/s. [PERSON] and [PERSON] [35] investigated the effect of convective and microwave-vacuum drying on the rehydration of mushrooms. They studied the impact of drying parameters (microwave power (115-285 W), system pressure (6.5-23.5 kPa) and product thickness (6-14 mm)) as well as drying temperature (50, 60 and 70 \({}^{\circ}\)C) on drying kinetics and rehydration characteristics. According to the authors, microwave-vacuum drying reduced drying time by 70-90%, and the dried products exhibited better rehydration properties compared to convective air drying. Additionally, system pressure had a significant effect on the rehydration ratio. The impact of microwave pre-drying and explosion puff drying on the physico-chemical properties, texture, microstructure and rehydration of pitaya fruit chips was studied by [PERSON] et al. [36]. The authors demonstrated that chips dried using microwave drying (1.0, 2.0 and 4.0 W/g) and explosion puff drying exhibited faster rehydration rates. [PERSON] et al. [37] dried peppers (_Lamyov variety_) at four different inlet air temperatures ranging from 50 to 80 \({}^{\circ}\)C and rehydrated the dried samples in water at 30 \({}^{\circ}\)C to examine the effect of drying temperature on the quality and microstructural properties of the rehydrated tissue. Additionally, they investigated the impact of pretreating the samples (soaking them in NaCl, CaCl\({}_{2}\) and Na\({}_{2}\)S\({}_{2}\)O\({}_{5}\) solutions) before drying at 70 \({}^{\circ}\)C. The study results indicated that the best product quality was achieved when the samples were pretreated before drying. Microscopic analysis of the rehydrated pepper samples suggested that cellular structure damage was minimized by the pretreatment, and the rehydrated peppers showed relatively better vitamin C retention, color and firmness. [PERSON] et al. [38] investigated the effect of freezing temperature on the quality properties of freeze-dried rice porridge at different temperatures. The authors observed that slow freezing resulted in a porous freeze-dried rice porridge with large pores and a more brittle structure compared to rapid freezing. They concluded that all the quality properties examined were significantly influenced by both the freezing temperature and the evaluation temperature. Both the initial rehydration ratio and the dissolution time of the freeze-dried rice porridge decreased with increasing water temperature. The ability of foods to absorb liquids also depends on the chemical composition of the material [39]; [PERSON] et al. [40] studied the effect of six carrot varieties on the water absorption of dried carrots. They found that variety had a significant effect on the rehydration process; [PERSON] et al. [41] studied the kinetics of rehydration of cowpea and bombara seeds, and the differences observed in the rehydration process emphasized varietal and species differences; [PERSON] et al. [42] studied the rehydration of vacuum-dried strawberries and aimed to investigate the effect of variety on properties.