Introduction: Tomato is one of the most valuable sources of minerals and vitamins supply in the human diet. Low shelf life of tomato and its short shelf life with inadequate processing facilities lead to heavy financial losses. Therefore, preserving and processing tomatoes is of the commercial importance (Liu et al., 2010). Drying is one of the preferred methods for keeping tomatoes (And and Barrett, 2006). Dried tomato products including half tomatoes, tomato slices and tomato powder, have a lot of consumption, compared with other tomato products. Among dried tomato products, tomato powder has a particular market. Powder production is an alternative method to extend the shelf life of foods (Liu et al., 2010). Usually the fruit powder is very dry, humidity absorber and has a lot of volumes. Therefore, during storage, transportation and administration, it requires special care and heavy packaging that will increase the cost. To overcome these problems, compression of the fruit powder in tablet form is a unique way. Tablet making of fruit powder has gained much popularity due to its ease of use, storage, transportation and product formulation (Aziz et al., 2018). After the tablet making process, the tablets contain high moisture content. They are not suitable for transportation and storage. So, in order to prevent the tablets corruption and maintain their quality, tablet drying is one of the important steps after the tablet making process. The drying process is an important operation that affects the quality and final price of the product (Mahapatra et al., 2018). Different drying methods play an important role in protecting foodstuffs. However, the effect of different drying methods on the quality of some foodstuffs is not clear. The purpose of this study was to drying process optimization of compressed tablet produced from tomato powder undergoing microwave-hot air conditions. Material and methods: First to remove the thin layer of fresh tomato peel, they were immersed in hot water for 30 to 45 seconds and then the tomato peel was easily separated. After the tomato peel was removed, cut with a sharp razor to 3 mm thick. For drying, the tomato sheets were placed on aluminum foil and the samples were dried in a semi-industrial continuous hot air dryer at 50 ° C at 1 m / s. After the drying process of the fresh tomatoes, the dried tomato slices were first poured into the mill and grinded for a minute. After the grinding process, tomatoes were sieved with a 50 mesh sieve (particle size less than 0. 5 mm) to homogenize the particle size. Prior to performing the pelletizing process, to increase the adhesion force between the particles, it is necessary to add the tomatoes, moisture and adhesives. According to pre-tests, moisture content of tomato powder was increased to d. b. 23%. 55% fructose syrup was also used as adhesive. The fructose syrup was dissolved in water by 6% by weight (by weight of tomato powder) and the resulting solution was added to the tomato powder and mixed with it. Refrigerate for 72 hours at 4 ° C. In order to compress the raw materials into a closed mold, a laboratory hydraulic press was used to perform tablet making experiments. Drying experiments were performed immediately after the tableting process was completed. Microwave-hot air dryer was used to dry compact spherical pellets produced from tomato powder. In this research, the effect of different conditions of microwave-hot air drying (air temperature, inlet air velocity and microwave exposure time) on the qualitative and chemical properties of the compressed tablet produced from tomato powder containing lycopene content, concentration of vitamin C, total phenol content, antioxidant activity and color indices of Δ L*, Δ a* and Δ b* were studied. To analyze the data and optimize the process, the response surface method and central composite design were used. Input parameters (independent) were: inlet air temperature, inlet air velocity and microwave exposure time. Dependent parameters (responses) were: lycopene content, concentration of vitamin C, total phenol content, antioxidant activity and color indices of Δ L*, Δ a* and Δ b*. For drying samples, five levels of air temperatures (40, 50, 60, 70 and 80 ° C), air velocity (0. 5, 1, 1. 5, 2, and 2. 5 m/s) and microwave exposure time (0, 4, 8, 12 and 16 seconds) were applied. Results and discussion: The amounts of lycopene content, concentration of vitamin C, total phenol content, antioxidant activity, Δ L*, Δ a* and Δ b* were achievd between 865 to 2205. 6 mg. 100gDM-1, 0 to 0. 88 mgascorbic/gDM, 0. 36 to 8. 9 mg GAE/g DM, 34. 95 to 99. 02%, 12. 89 to 18. 98, 5. 35 to 14. 609 and 6. 78 to 13. 21, respectively. The optimum drying point of the at air temperature of 50 ° C, air velocity of 1. 07 m/s and microwave exposore time of 4 seconds were obtained and the response variable values in the optimal point containing lycopene content, concentration of vitamin C, total phenol content, antioxidant activity and color indices of Δ L*, Δ a* and Δ b* were obtained 434. 7 mg/100gDM, 0. 66 mgascorbic/gDM, 7. 78 mg GAE/g DM, %50. 11, 14. 76, 8. 49 and 7. 61, respectively. The results showed that the with simultaneous increase air temperature and the microwave exposure time, concentration of vitamin C decreased. The decrease in ascorbic acid observed during microwave drying may be due to the degradation of vitamin C by electromagnetic waves from microwave power in dried samples. also with increasing temperature, the amount of lycopene Increased. This increase in lycopene is due to the fact that carotenoids, especially lycopene, are complexed in the cellular matrix of fruits and vegetables, and processes such as crushing, cooking, and heating cause the release of lycopene from the tomato cellular matrix. As the temperature of the inlet air into the drying chamber increased and the microwave duration increased, the total phenol content of the compacted tablet produced from tomato powder decreased. The reason for this decrease is that heat treatment may release more phenolic acid from the breakdown of cellular components. Although disruption of the cell wall also releases oxidizing and hydrolytic enzymes that can destroy antioxidants in fruits and vegetables, but low temperature heat treatment disables these enzymes to prevent acid degradation and loss of acidity. The phenolics are reduced. With a simultaneous increase in intake air temperature and air velocity input, the antioxidant activity of tomatoes tablets increased with increased microwave exposure time antioxidant activity of tomatoes fell tablets. The reason for this increase is that while heating is the main cause of the degradation of antioxidants such as ascorbic acid, but heat can trigger the formation of compounds such as melanoids in the myard reaction, and these compounds can have antioxidant effects that lead to increased It becomes antioxidant. The results showed that increasing the temperature caused a greater difference between the color indices L* and a* and a decrease in the color index b* compacted tomato tablets compared to fresh tomatoes. The increase in temperature caused more darkening (decrease in L* index) and decrease in redness (decrease in a* index) in tomato compacted tomato. That is, the specimens became darker than the former, due to the formation of a brown grain through the Mayard reaction. Generally, the color indices at lower temperatures were closer to the values of fresh tomato samples. Conclusion: Results indicated that the drying under lower temperature (50° C) and lower exposore time of microwave radiation (4 seconds) with fixed power (90 W) caused to further ingredient materials preservation and increasing in desirability index.