The Effect of Drying Temperature and Thickness on the Drying Kinetic, Antioxidant Activity, Phenolic Compounds, and Color Values of Apple Slices

Abstract

Dried fruit slices are important, healthy, and popular snacks and gain importance day by day due to their high nutritional content. In this context, this study mainly focused on the production of healthy apple chips snacks and the determination of degradation kinetics of antioxidant activity, total phenolic compounds, and color values of apple chip snacks during convective hot air drying at three different temperatures (45, 55, and 65°C) and sample thicknesses (1.5 and 5 ± 0.5 mm). The drying kinetics, desorption isotherms, activation energy, and half-life of the apple chip snack were also calculated. The Page and GAB models are the best models for the determination of the drying (>0.992) and desorption (>0.9979) behavior of apple snacks with the highest R2 values. The drying of all samples took place in the falling rate period. The Deff values increased depending on the increasing air temperature and slice thickness. The antioxidant activity, total phenolic compounds, and total color change of the 5 mm thick samples were degraded following the first-order reaction kinetics. The higher antioxidant activity, phenolic compounds, L∗ values, and lower half-life values were observed in conditions where the thickness (1.5 mm) and temperature (45°C) are low. The activation energy values calculated for the total phenolic compounds are higher than those calculated for the antioxidant activity. As a result, it can be concluded that apple chip snacks with high nutritional value can be produced by choosing low temperatures and slice thickness.

Qualitative, energy and environmental aspects of microwave drying of pre-treated apple slices

“…The DT reduced by increasing the microwave power due to faster mass transfer in the apple slices at a higher microwave power as a result of more heat generation and a large vapor pressure difference between the center and the surface of the product 56 . The DT also decreases by reducing the sample thicknesses as the exit of moisture will become easier, accelerating the moisture movement from the texture of the material to the sample surface 57 . Thus, drying speed increases incrementally at low thicknesses 4 .…”

Optimization of production of blanched apple chips using sublimation drying

“…Pretreatment methods, such as acid treatment and freezing, influence cell structure and the quality of the final product. The focus of research by Demiray et al (2023) lies in optimizing the microwave drying process to preserve quality and expedite the overall procedure. Similarities with our study lie in the shared aim of optimizing drying methods and pretreatment to enhance the characteristics of dried products.…”

“…Research by Demiray et al (2023) concentrates on the production of healthy apple chips, determining the kinetics of antioxidant activity degradation, total phenolic content, and color characteristics during convective drying with hot air at different temperatures and thicknesses of sliced apples. The findings from Demiray et al (2023) support the choice of low temperatures and thicknesses for apple chip production with high nutritional content. These results align with our research.…”

Impact of Air-Drying Temperatures on Drying Kinetics, Physicochemical Properties, and Bioactive Profile of Ginger

“…This comparison further validates the accuracy of the Midilli model at each drying temperature. In advancing our modeling of moisture ratio, we integrated temperature effects into the Midilli model by employing the Arrhenius equation, commonly used to characterize the impact of temperature on various food reactions [50]. The Arrhenius equation elucidates the relationship between the reaction rate (in this context, the drying rate) and temperature as follows:…”