Effect of Different Drying Methods on the Physico-Chemical Properties of Tomato Variety 'Rio Grande'

The aim of this work is to study the physico-chemical properties of dried tomatoes, variety Rio grande using direct solar dryer (DSD), open-air sun drying (OASD) and microwave drying (MW) with three output powers density (1w/g; 2w/g; 3w/g) at different temperatures (57, 67 degrees C). Radical scavenging activity of tomatoes extracts was investigated. Results indicated that drying tomatoes by microwave (3W/g; 67 degrees C) is faster than open-air sun drying (OASD) and direct solar dryer (DSD). The studied parameters (moisture, pH, degrees Brix, total phenolics, total flavonoids, and carotenoids content) were significantly affected by different drying processes, with minimal effects on pH. The highest activity against the DPPH radical oxidation is investigated in methanolic extracts of tomatoes dried by direct solar dryer (DSD). Nevertheless, the highest ABTS value was observed in methanolic extracts of tomatoes dried by microwave (MW) with 3w/g at 57 degrees C.