Chemical and Thermal Treatment for Drying Cassava Tubers: Optimization, Microstructure, and Dehydration Kinetics

Area of Science:

• Food Science and Technology
• Agricultural Engineering
• Chemical Engineering

Background:

• Cassava preservation is crucial for industrial applications due to its perishable nature.
• Optimizing pretreatment and understanding drying kinetics are vital for effective postharvest management.
• Response surface methodology aids in optimizing complex food processing parameters.

Purpose of the Study:

• To optimize cassava pretreatment using response surface methodology.
• To evaluate the impact of chemical and thermal pretreatments on cassava quality attributes.
• To model and analyze the dehydration kinetics of pretreated cassava.

Main Methods:

• Central composite design (CCD) for response surface methodology.
• Investigated sodium metabisulfite (0-4%), citric acid (0-4%), and blanching time (0-4 min).
• Assessed moisture content, whiteness index, activation energy (E), and effective moisture diffusivity (D).
• Applied five drying models to evaluate dehydration kinetics.

Main Results:

• Optimal pretreatment: 1.31% citric acid, 1.03% sodium metabisulfite, 1.01 min blanching.
• Moisture content: 5.82-9.42% db; Whiteness index: 87.16-94.23.
• Effective diffusivity (D): 5.06 × 10⁻⁹ to 6.71 × 10⁻⁹ m²/s; Activation energy (E): 29.65-33.28 kJ/mol.
• Logarithmic model best described dehydration kinetics (R²=0.9859).

Conclusions:

• Optimized pretreatment significantly impacts cassava microstructure and drying characteristics.
• The logarithmic model accurately predicts cassava dehydration under optimal conditions.
• This research provides a framework for efficient cassava processing and preservation.