Enhancing Physicochemical Characteristics of Donkey Meat through High-Voltage Electrostatic Stimulation during Acid Excretion

To investigate the impact of high-voltage electrostatic stimulation on the quality of donkey meat, ten 30-month-old Dezhou donkeys (each weighing 250 ± 50 kg) were selected. Following slaughter, longissimus dorsi (LD) samples from both left and right carcasses were collected. The control group refrigerated the right muscle in a 0–4°C refrigerator for normal acid excretion. Meanwhile, the high-voltage electrostatic group subjected the left muscle to high-voltage electrostatic stimulation (30000 V) for 60 s before refrigerating it in the same conditions for acid excretion. The study showed that at the 1st, 6th, and 24th h of acid excretion, the high-voltage electrostatic group exhibited significantly lower pH levels than the control group (P<0.05). Furthermore, a∗ values in the high-voltage electrostatic group showed an increasing trend relative to the control group at the 6th and 24th h of acid excretion (P = 0.0751, P = 0.0860). With increasing acid excretion time, both treatment groups displayed increased PV and TBARS values. At 48 and 72 h, the PV values in the high-voltage electrostatic group were significantly lower than those in the control group (P < 0.05). As acid excretion time increased, T-AOC, SOD, and GSH-Px in both groups decreased. However, the high-voltage electrostatic group consistently exhibited higher antioxidant enzyme activity than the control group at all time points. SOD and GSH-Px activity in the high-voltage electrostatic group showed an increasing trend at 48 h of acid excretion (P = 0.0838, P = 0.0860). At 72nd h of acid excretion, the shear force of donkey meat in the high-voltage electrostatic group was significantly lower than that in the ordinary treatment group (P < 0.05). With increasing acid excretion time, the MFI of both treatment groups gradually increased. In particular, at the 1st and 48th h of acid excretion, the MFI of the high-voltage electrostatic group was significantly higher than that of the ordinary treatment group (P < 0.05). Following high-voltage electrostatic stimulation, ultrastructure images of donkey meat at 6 and 72 h revealed numerous contractions and stretching bands. Therefore, this stimulation significantly improved the tenderness of donkey meat, reduced the oxidation rate of donkey meat, and improved the quality of donkey meat.