International Journal of Food Science and Nutrition

Authors
BK Pooja, SL Jagadeesh, SJ Prashanth, Shashikanth Evoor, Itigi Prabhakar

Abstract
An experiment for standardization of size/shape and pre-treating chemicals for dehydration of onion under solar tunnel dryer was conducted in the Department of Post Harvest Technology, College of Horticulture, Bagalkot, Karnataka during the year 2017-18. Fresh onion and tomatoes were prepared for dehydration by cutting into different size/shapes (S₁ - Dices and S₂ - Slices of onion) and subjected to different chemical pre-treatments for a specified duration. Onions and tomatoes thus prepared were dehydrated in solar tunnel dryer and analyzed for different physico-chemical qualities. In dried onion, the slices (S₂) recorded significantly minimum moisture content (13.80%), minimum drying time (57.17 hours), higher rehydration ratio (2.98) and significantly higher sensory score. Among pre-treatments, T₂ (0.25% KMS for 15 min), T₃ (0.1% KMS + 2% CaCl₂ for 5 min) and T₆ (0.5% Na₂S₂O₅ for 20 min) were found superior with respect to various physico-chemical and sensory properties.