Optimizing radiofrequency assisted cryogenic freezing to improve meat microstructure and quality

Radiofrequency-assisted nitrogen cryogenic freezing previously proposed was optimized to increase meat quality. Continuous cryogenic (CCF, for 2.5 min) and pulsed cryogenic (PCF, 3 s pulse with 10 s interval for 10 min) freezing were set up. CCF and PCF were then combined with radiofrequency (RF) pulses to set up RF-CCF (10 s 2 kV RF pulse with 20 s interval during 2.5 min of continuous N2 flow) and RF-PCF (30 s 2 kV RF pulse with 60 s interval, during 3 s nitrogen pulse with 10 s interval for 10 min). These processes were compared with slow (SF) and blast (BF) freezing. Meat quality (i.e., microstructure, drip loss, color, firmness) decreased in the order RF-PCF ≥ PCF > RF-CCF > BF > SF > CCF, indicating that nitrogen pulsing considerably reduced tissue damages and its combination with RF was crucial to further preserve tissue integrity. RF-PCF could be adapted to different matrices by tuning processing conditions.