Studies on Effects of Drying Methods on Quality Characteristics of Tomato Pulp Leather

¹ Assistant Professor, Department of Food Processing and Technology, Gautam Buddha University), Greater Noida, India, 201312
² M. Tech Student, Department of Processing and Food Engineering, SHUATS, Prayagraj, India, 211007

^* Corresponding author: chitra.sonkar@shiats.edu.in

Abstract

The present study investigated the drying characteristics and quality attributes of tomato pulp leather prepared using tray drying and hot air oven methods at temperatures of 60°C, 65°C, and 70°C. Sensory evaluation identified the best samples as T3 (hot air oven at 70°C for 6-5 hours) and T5 (tray dryer at 65°C for 8-9 hours), which exhibited superior drying and sensory characteristics according to a 9-point hedonic scale. Physicochemical analysis revealed that the moisture content, ash content, pH, total soluble solids (TSS), total sugars, and vitamin C content decreased gradually during the 45-day storage period for both T3 and T5 samples. The initial moisture content of the prepared tomato pulp leather was 18.5% and 18.6% for T3 and T5, respectively, which decreased to 17.9% for both samples by the 45th day of storage. The ash content, pH, TSS, total sugars, and vitamin C content also showed a decreasing trend during storage. The drying kinetics of the T3 sample showed a maximum drying rate of 0.33 g/min in the first hour, which decreased to g/min in the last hour, reaching an equilibrium moisture content of 18.5% after 7 hours of drying. The decrease in drying rate was consistent with the lower rate of moisture diffusion inside the tomato pulp leather compared to the rate of moisture evaporation from the surface. In conclusion, tray drying at 70°C for 7 hours proved to be the most effective method for producing high-quality tomato pulp leather, ensuring optimal drying rate, superior retention of nutrients, and good sensory attributes, making it suitable for commercial production of tomato-based snack products. Microbiological analysis revealed that yeast and mold counts increased gradually during the 45-day storage period. However, the microbial load remained within acceptable limits, ensuring the microbiological safety of the tomato pulp leather throughout storage.