A mathematical model for predicting the transport process and quality changes during intermittent microwave...

Area of Science:

• Food Science and Technology
• Chemical Engineering
• Drying Technology

Background:

• Intermittent microwave convective drying (IMCD) utilizes volumetric heating for efficient drying.
• Accurate prediction of heat and mass transfer, alongside quality changes during IMCD, is vital but understudied.
• Understanding these factors is essential for optimizing drying processes and final product quality.

Purpose of the Study:

• To develop a predictive model for intermittent microwave convective drying (IMCD).
• To couple heat and mass transfer with quality degradation kinetics.
• To investigate the impact of power ratio (PR) on drying kinetics and product quality.

Main Methods:

• Integrated a simultaneous heat and mass transfer model with Maxwell's equations for microwave heating.
• Incorporated chemical reaction kinetics for quality degradation.
• Validated the model against experimental results for moisture, temperature, and bioactive compounds.

Main Results:

• The developed IMCD model accurately predicted moisture and temperature distributions.
• The model successfully predicted changes in total phenolic content (TPC) and ascorbic acid (AA) levels.
• Power ratio (PR) significantly influenced quality attributes; lower PR (1/4, 1/5) reduced AA degradation compared to PR 1/3.
• TPC degradation was prominent in the initial drying phase but stabilized later.

Conclusions:

• The coupled model provides accurate predictions for IMCD processes.
• Optimizing power ratio is key to preserving nutritional quality (AA, TPC) during IMCD.
• The model serves as a valuable tool for controlling IMCD parameters and ensuring product quality.