Optimization of the Vacuum Microwave Drying of Tilapia Fillets Using Response Surface Analysis

Area of Science:

• Food Science and Technology
• Agricultural Engineering
• Materials Science

Background:

• Tilapia (Oreochromis spp.) is a globally significant fish species.
• Effective drying methods are crucial for preserving fish quality and extending shelf life.
• Vacuum microwave drying (VMD) offers potential for rapid and efficient fish processing.

Purpose of the Study:

• To investigate the effects of vacuum microwave drying (VMD) parameters on tilapia fillet quality.
• To determine the optimal VMD conditions for enhancing key quality attributes of tilapia fillets.
• To develop and validate a predictive model for VMD effects on tilapia quality.

Main Methods:

• Utilized a Box-Behnken design for experimental optimization.
• Varied fillet thickness (3-7 mm), microwave power (132-396 W), and vacuum pressure (0.03-0.07 MPa).
• Assessed quality parameters including water activity (Aw), texture (hardness, elasticity), rehydration rate, and whiteness.

Main Results:

• Fillet thickness significantly impacted quality: 3 mm fillets had low Aw and high hardness; 7 mm fillets showed superior rehydration, elasticity, and whiteness.
• Increasing microwave power generally decreased Aw and whiteness, while initially improving then reducing texture and rehydration.
• Higher vacuum pressure led to lower Aw and improved whiteness and elasticity.

Conclusions:

• Optimal VMD conditions for tilapia fillets were determined as 7 mm thickness, 330 W microwave power, and 0.06 MPa vacuum pressure.
• These conditions resulted in a high comprehensive quality score of 93.94.
• The developed regression model accurately predicted drying effects, demonstrating high reliability with only 1.45% deviation.