A Novel Alternative Method for Modeling the Effects of Air Temperature and Slice Thickness on Quality and Drying Kinetics of Tomato Slices: Superposition Technique

Abstract

The effect of air temperature (AT) and slice thickness (ST) on the quality and drying kinetics of tomato slices were studied. The drying period of tomato slices to reach the moisture content of 15% (wb) ranged from 2.6 to 18.7 h. The water diffusivity, activation energy, and resistance to diffusion ranged from 1.4 × 10⁻¹⁰ to 2.8 × 10⁻⁹ m²/s, 21.25 to 23.4 kJ/mol, and from 939 to 4590 m² s/kg, respectively. Drying had a significant effect on ascorbic acid, soluble solid, acidity, and pH (P = 0.01). The ascorbic acid degradation was greatly influenced by ST. The results show that time-temperature superposition technique (TTST) was very efficient in the modeling of the drying process. The proposed TTST provides a novel alternative in curve-fitting exercise of drying data. Neural networks also showed favorable performance in estimating the drying functions.

Keywords:

• Ascorbic acid
• Diffusivity
• Drying
• Master curve
• Neural network
• Superposition technique
• Tomato slices

ACKNOWLEDGEMENTS

The authors thank the University of Tehran for technical support of this research project.

Notes

Values followed by different letters are significantly different at the 0.01 level.

Values followed by different letters are significantly different at the 0.01 level.

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For each property, values followed by different letters in each column and row are significantly different at the 0.01 level.

Values followed by different letters in each column are significantly different at the 0.01 level.