Analysis and comparison of Osmosed and non-Osmosed Aloe Vera gel drying kinetics in optimized condition

The demand for nutritious food with longer shelf life and preservatives-free has increased significantly throughout the world. Today, processing of aloe vera gel plays a key role due to its application in the food industry.1 Osmotic dehydration is the process of water removal with low energy consumption and temperature.2 However, this process cannot provide products with enough low moisture content and long shelf life. Therefore, osmotic products need to be further dried by the air, vacuum or freeze dryer and so on.3 In this study, 20 osmotic dehydration experiments were designed on aloe vera gel by using response surface methodology (RSM). Optimization of osmotic dehydration experiments was done based on maximizing water (WL) and minimizing solid gain (SG). After choosing an optimized osmotic condition, further drying experiments of aloe vera gel slabs were done in a tray dryer at different temperatures (50, 65, 80˚c). Thereafter, drying kinetics of osmotic and non-osmotic dried samples were evaluated (Fig.1). Results show that Osmotically dehydrated samples at all temperatures have dried in a shorter time than non-osmotic dried samples. As a result, with regard to the shorter drying time of Osmo-dried samples in comparison to non-Osmo dried ones and less probable heat damage to superficial and qualitative properties of final products, the Osmo-dried sample at 50˚c was chosen as the best sample.

کلیدواژه ها:

Aloe Vera ، Osmotic dehydration ، Optimization ، Drying kinetics.