Optimization of drying parameters for production of high-quality tomato powder

Abstract:

The global tomato powder market has been growing at roughly 6% per year, driven by demand from the instant food and seasoning industries, yet quality inconsistency remains a persistent complaint among buyers ^[1]. This research optimised hot-air drying parameters for tomato powder production using Response Surface Methodology (RSM) with a central composite design. Three factors were varied: drying temperature (50-70°C), air velocity (1.0-2.0 m/s), and slice thickness (2-6 mm). Response variables included lycopene retention, colour (L*, a*/b* ratio), rehydration ratio, and drying time. Optimal conditions were 60°C, 1.5 m/s, and 4 mm slice thickness, yielding 81.4% lycopene retention, L* value of 38.3, and a rehydration ratio of 4.7. Drying time at optimal settings was 8.5 hours. Temperatures above 65°C caused rapid lycopene degradation and browning. These parameters provide a practical guideline for small-to-medium tomato processors in the Marmara region.