Optimizing Non-Thermal Magnetic Field to Minimize Weight Loss and Tissue Degradation: Identifying Possible Enzyme...

Area of Science:

• Agricultural Science
• Food Science
• Biophysics

Background:

• Post-harvest quality of climacteric fruits like tomatoes (Solanum lycopersicum L.) is compromised by enzymatic degradation, leading to weight loss and softening.
• Novel treatments are needed to inhibit cell-wall-degrading enzymes and extend the shelf life of fresh produce.
• Magnetic fields (MF) are being explored for their potential to modulate biological processes in food preservation.

Purpose of the Study:

• To investigate the potential of magnetic field (MF) treatments in inhibiting cell-wall-degrading enzymes in tomatoes.
• To optimize MF processing parameters (intensity, frequency, duration) for maximum post-harvest quality preservation.
• To elucidate the underlying mechanisms by which MF affects key enzymes (pectin esterase, polygalacturonase, cellulase) and tomato tissue integrity.

Main Methods:

• Optimization of MF parameters (1-3 mT intensity, 0-100 Hz frequency, 10-30 min duration) using an orthogonal array design.
• Assessing the impact of MF treatment on enzymatic activity, including pectin esterase (PE), polygalacturonase (PG), and cellulase (Cx).
• Evaluating post-harvest quality attributes: weight loss, soluble solids, titratable acidity, and tissue integrity via cross-sectional imaging.

Main Results:

• Optimal MF treatment (2 mT, 50 Hz, 10 min) significantly inhibited weight loss (4.22%) and maintained tissue integrity for 21 days.
• MF treatment delayed the increase in soluble solids by 1.5 times and reduced titratable acidity by 1.2 times.
• Significantly suppressed enzyme activity: PE by 1.5 times, PG by 2.8 times, and Cx by 2.5 times, preserving tomato structure.

Conclusions:

• Magnetic field treatments offer an effective strategy to suppress key enzymes responsible for tomato tissue degradation.
• Optimized MF application delays post-harvest weight loss and softening, thereby preserving the quality of tomatoes.
• These findings support the use of MF technology for sustainable food production and reducing food waste.