Effects of Different Types of Electric Field Combined with Controlled Freezing-Point Storage on Water Retention Properties of Fresh Pork

In order to study the effects of different types of electric field combined with controlled freezing-point storage on the water retention properties of fresh pork, the changes in the moisture content, storage loss, cooking loss, transverse relaxation time T₂, surface hydrophobicity and structure of myofibrillar protein in pork Longissimus dorsi were comparatively analyzed under different storage conditions, namely alternating electric field-assisted controlled freezing-point storage (−1.0 ± 0.5) ℃, electrostatic field-assisted controlled freezing-point storage and controlled freezing-point storage (control group). The results showed that the moisture content and relaxation peak area percentage (P₂₁) for immobile water in the alternating electric field and electrostatic field treatment groups were significantly higher than those in the control group (P < 0.05), and the storage loss, cooking loss, surface hydrophobicity of myofibrillar protein and relaxation peak area percentage (P₂₂) for free water were significantly lower than those in the control group (P < 0.05), but there was no significant difference between the electrostatic field treatment groups. In conclusion, both electrostatic fields can delay the degradation of myofibrillar protein and the transformation of immobile water into free water, consequently improving the water retention properties and reduce the juice loss of fresh pork during storage.