DETERMINATION OF THE APPROPRIATE DRYING PARAMETERS, STORAGE DURATION AND PACKAGING MATERIAL FOR TOMATO FRUIT USING FLUIDIZED BED DRYER

Abstract

Tomato is a highly nutritious but perishable crop that experiences significant postharvest losses due to its high moisture content and inadequate preservation methods. This study evaluated the effects of fluidized bed drying parameters, packaging materials, and storage duration on the quality of dried tomato. A Box–Behnken response surface design was employed to optimize three drying variables: temperature (55–70°C), hot air velocity (0.8–1.2 m/s), and slice thickness (3–7 mm). Fresh tomato slices were dried to a water activity below 0.6, after which the optimized samples were packaged in glass jars, plastic containers, and low-density polyethylene bags and stored under ambient conditions for five months. Proximate composition, lycopene, β-carotene, microbial quality, and sensory attributes were evaluated monthly. The results showed that drying parameters significantly (p < 0.05) influenced the nutritional composition and carotenoid contents of dried tomato. Increasing drying temperature and air velocity reduced moisture content while improving lycopene retention but resulted in lower β-carotene content. The optimum drying conditions were identified as 70°C drying temperature, 0.9 m/s air velocity, and 5 mm slice thickness, producing dried tomato with desirable nutritional quality and low moisture content. During storage, moisture content, carbohydrate, fat, and microbial counts increased, whereas protein, ash, crude fibre, lycopene, β-carotene, and sensory quality gradually declined. Among the packaging materials, glass jars and plastic containers provided better preservation of product quality than low-density polyethylene bags, while unpackaged samples deteriorated most rapidly. The study demonstrates that optimizing fluidized bed drying conditions combined with appropriate packaging can effectively enhance the quality and storage stability of dried tomato, thereby reducing postharvest losses and improving its shelf life.