Osmotic Dehydration as a Factor in Freezing of Tomato
The objectives of this study were to investigate the influence of osmotic solutions and their concentration on mass transfer and observe any effect on lycopene content, color and melting temperature (Tm) of tomatoes. The tomato pieces were osmosed in maltose (35, 50%), sucrose (35, 60%) and sorbitol (35, 60%), solutions for 2 and 6 h. Sucrose and sorbitol were highly effective in reducing water content in tomatoes, compared to maltose. Highest solid gain was found by using sorbitol. The 60% of sucrose and sorbitol caused the reduction of lycopene content and alternation of color. The evaluation of Tm was depended on osmotic agents and could be related with the solid mass fraction. The 50% was recommended for the frozen tomatoes, compared to sucrose and sorbitol.