Optimization of a Diced Tomato Calcification Process

The effect of calcium concentration (0.05-1.45% CaCl₂), temperature of dipping solution (35-65°C), and contact time (0.5-3.5 min) on calcium uptake, firmness and pH of diced tomatoes was evaluated during a calcification process using response surface methods. Temperature had no significant effect on the process. Application of graphical optimization techniques revealed that processing in a solution of relatively low calcium concentration (?0.43% CaCl₂) at ambient temperature (? 35°C) for about 3.5 min would yield a product with Ca⁺⁺ content below the legal limit (<800 μ-g/g), improved firmness (shear force value > 20 N/g), and with pH low enough (<3.95) to eliminate any requirement for acidification treatment.