Effects of High-Frequency Electrical Stunning Current Intensities on Serum Variables, Meat Quality, Protein...

Despite the significance of electrical stunning (ES) for meat quality, optimal parameters in geese remain poorly established. This study tested the hypothesis that high-frequency (500 Hz) ES near 43 mA would improve meat quality. Forty 92-day-old male Yangzhou geese were divided into five treatments (eight replicates each): a non-stunned control (0 mA) and four groups stunned with alternating current (500 Hz, 10 s) at 21.75 (E22 mA), 43.25 (E43 mA), 71.13 (E71 mA), or 98.75 mA (E99 mA). Key measurements included drip loss, cooking loss, shear force, water retention (via transverse relaxation populations T21 and T23), protein solubility, glycogen, and lactic acid in breast and thigh muscles. Results showed quadratic relationships between current intensity and water distribution: Breast T23 (free water) reached its minimum and Thigh T21 (weakly bound water) its maximum at 43.25 mA (p < 0.05). Breast meat color (redness, yellowness), thigh meat redness, and total extractable protein solubility declined linearly with increasing current (p ≤ 0.01). Breast muscle glycogen was reduced in the E99 mA group compared to controls and E22 mA by Day 2 (p < 0.05). Thigh muscle showed quadratic trends for glycogen and lactate, with maximal glycogen and lactate in E43 mA at Day 0 (p < 0.05). Overall, although no significant effects were observed on primary quality attributes (drip loss, cooking loss, shear force, or color) across currents ranging from 21.75 to 98.75 mA, treatment at 43.25 mA improved water distribution as measured by low-field nuclear magnetic resonance (NMR), suggesting a potential to enhance water retention during further processing or storage.