Time-Dependent Heat Transfer Coefficients of Standard Cans during Pasteurization

Area of Science:

• Food science and technology
• Chemical engineering
• Heat transfer

Background:

• Canned food pasteurization involves heating to deactivate enzymes, followed by cooling.
• Accurate heat transfer analysis is crucial for effective pasteurization and determining come-up times.

Purpose of the Study:

• To analyze heat transfer in canned juice using computational fluid dynamics (CFD).
• To compare detailed conjugate heat transfer simulations with a simplified boundary condition approach.
• To investigate the impact of water bath temperature on pasteurization efficiency.

Main Methods:

• Utilized CFD to simulate heat transfer in 330 mL, 500 mL, and 1000 mL juice cans.
• Employed both detailed conjugate heat transfer and simplified boundary condition methods.
• Validated simulation results against experimental data, achieving a 2% margin of error.

Main Results:

• CFD simulations accurately predicted time-temperature profiles, aligning with experimental data.
• Identified distinct heating and cooling stages significantly impacting internal temperature profiles.
• Observed nearly identical heat transfer coefficients on inner and outer can surfaces.
• Confirmed cold spots at the bottom and hot spots at the top due to natural convection.
• Increasing water bath temperature from 60°C to 80°C reduced come-up times by 12-15%.

Conclusions:

• CFD simulations are essential for precise pasteurization come-up time determination.
• Heat transfer dynamics within canned foods are complex, influenced by multiple stages.
• Optimizing water bath temperature offers a viable strategy to enhance pasteurization efficiency and reduce processing time.