Electrical impedance and tenderisation in bovine meat

The electrical properties and the muscle fibre mechanical resistance of dif ferent beef muscles were measured between 1 and 14 days post-mortem. Electr ical measurements used different electrode types working by contact with or penetration of muscle. Measurements from the different electrode types wer e strongly, correlated (0.83 < r(2) < 0.96). Both impedance (Z) and the rat io Z(1) kHz/Z(100) kHz decrease during ageing. These parameters show an alm ost linear relationship with muscle fibre mechanical resistance. However, t he slope of these curves for one muscle changed among animals. Therefore, t hese electrical parameters are not useful for the prediction of the state o f ageing. Meat electrical anisotropy decreases both when frequency increase s and with ageing. Electrical anisotropy measured at 1 kHz is significantly (r = 0.59, N = 129 P < 0.01) correlated to muscle fibre mechanical resista nce. The mean anisotropy decreases linearly with muscle fibre mechanical re sistance in the same way for Semimembranosus and Pectoralis Profundus muscl es. When meat is fully aged it is almost electrically isotropic. Electrical anisotropy is, therefore a potential parameter to evaluate meat ageing, bu t improvements in accuracy are needed before it can be used. (C) 2001 Elsev ier Science Ltd. All rights reserved.