ORIGINAL RESEARCH The Influence of Natural Basil Seed Gum Coats on the Kinetics of Osmotic Dehydration of Apple Rings Ahmad Etemadi 1 & Reza Alizadeh 1 & Mohammad Sirousazar 2 Received: 21 February 2020 /Accepted: 9 July 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract Edible basil seed gum is well known as a safe and beneficial material in the food industry. The effect of the gum concentration was studied as a coating solution on apple rings in the osmotic dehydration process. Water loss, solid gain, water, and solid diffusion coefficients, and performance ratio were selected as important parameters to be studied. Furthermore, different con- centrations and temperatures of sucrose solution were investigated as osmotic process parameters. Equilibrium values of solid gain and water loss have been predicted by Azuara model. Mass transfer diffusion coefficients have been appropriately calculated by the analytical solution of Fick’s second law of diffusion. Water and solid diffusion coefficients varied in the ranges of 2.78 × 10 -10 –13.21 × 10 -10 (m 2 /s) and 1.4 × 10 -10 –5.34 × 10 -10 (m 2 /s) respectively, in different operational conditions. The optimal operating condition to gain maximum performance ratio was obtained at 60 °C for concentrations of 0.3 wt.% gum and 60 wt.% osmotic sucrose solutions. Considered conditions resulted in a maximum performance ratio of 9 kg of water removal per 1 kg of solid gain. Coated samples showed 18% lower sucrose absorption in comparison with non-coated apples. Keywords Edible coating . Basil seed gum . Apple rings . Sucrose diffusivity . Performance ratio . Mathematical modeling Introduction There are numerous methods to reduce the wastes of food materials. The most popular and common method of raising the product shelf life is to reduce the free moisture of food material by one of the several methods of dehydration and drying of food materials. Moisture reduction results in water activity decrease in food material and promotes the final prod- uct shelf life(Khin Mya et al. 2005). Several types of research related to drying of fruits and vegetables have been developed in order to reduce the amount of food waste, increase the production of more nu- tritious food, and finally lead to change the consumers’ life- style (Ferrari et al. 2013; Díaz-Mula et al. 2012). The osmot- ic dehydration has numerous benefits in comparison with other drying methods, including removal of unbounded wa- ter without phase change and with the lowest amount of consumed energy, as well as improving the organoleptic properties such as texture, color, taste, and nutritional value of products (Mayor et al. 2008; Rastogi et al. 2002; Azarpazhooh and Ramaswamy 2012). In this process, food materials are immersed in a hypertonic solution for a deter- mined period. One of the characteristics of the hypertonic solution is having a high osmotic pressure and a water activ- ity lower than that of fresh fruits and vegetables (Monnerat et al. 2010). In the osmotic dehydration process, two main countercur- rent flows, including water flow and osmotic agent flow, exist simultaneously. The main reason for mass transfer in the os- motic dehydration process is the difference between the chem- ical potential of the food material and the osmotic solution. The rate of water removal in osmotic dehydration from fruit tissues depends on factors such as temperature and concentra- tion of osmotic solution, size, and shape of the material and food to osmotic solution mass ratio (Souraki et al. 2014; Rastogi et al. 2002). The most effective temperature range for preserving nutritional value, color, taste, and texture of the fruit has been reported between 25 and 65 °C (Torreggiani and Bertolo 2001). * Reza Alizadeh r.alizadeh@sut.ac.ir 1 Chemical Engineering Faculty, Sahand University of Technology, P.O. Box 51335/1996, Tabriz, Iran 2 Faculty of Chemical Engineering, Urmia University of Technology, Urmia, Iran Food and Bioprocess Technology https://doi.org/10.1007/s11947-020-02492-z