Document Type : Original research

Authors

• Samira Baratian Ghorghi ¹
• morteza kashaninejad ²
• Mohsen Heydari ²
• Khashayar Sarabandi ³
• Alireza Vasiee ⁴

¹ M.Sc. in Food Science Engineering, Department of Food Science and Technology, Ferdowsi University of Mashhad (FUM), Mashhad, Iran.

² Assistant Professor, Department of Green Technologies in Food Processing, Research Institute of Food Science and Technology (RIFST), Mashhad, Iran

³ Assistant Professor, Department of Food Chemistry, Research Institute of Food Science and Technology (RIFST), Mashhad, Iran

⁴ Assistant Professor, Department of Food Safety and Quality Control, Research Institute of Food Science and Technology (RIFST), Mashhad, Iran

Abstract

In this study, the effects of combined drying method (Osmotic-Hot Air) on the structural, color, and kinetic properties of apple cuboids were investigated. Experiments were conducted using Box-Behnken design at three levels of drying temperature (60, 70, and 80°C), three slice thicknesses (5, 10, and 15 mm), and three sucrose osmotic solution (40, 50, and 60%). Results showed that the overall effective diffusion coefficient of the tested samples varied between from 4.36 × 10-9 to 1.46 × 10-7 m2/s. The activation energy of samples ranged from 20.01 to 33.94 kJ/mol, increasing with slice thickness and sucrose osmotic solution. Among eight investigated models, the Midilli model demonstrated the best fit with experimental data, showing a coefficient of determination above 0.99. The browning index of samples varied between 140.54 to 140.83, with increases in slice thickness and drying temperature leading to higher browning indices, while increasing sucrose concentration from 40% to 60% resulted in decreased browning index. Analysis of Gray Level Co-occurrence Matrix (GLCM) parameters revealed that temperature increase led to higher energy, correlation, and homogeneity while reducing entropy. Conversely, increasing sample thickness resulted in decreased energy and correlation while increasing homogeneity and entropy. PLS regression analysis further confirmed the significance of drying temperature on GLCM parameters.

Keywords

• Apple
• Drying kinetics
• Hot air
• Osmotic dehydration

Main Subjects

• Effect of different processes on the functional properties of foods or drinks