Abstract
Pulsed electric field (PEF) processing is a non-thermal food processing technology that applies brief (μs) electrical pulses of high voltage to food products placed between two electrodes. Depending on the process intensity, the process affects cell membrane permeability due to localised structural changes. There are few reports on the use of PEF for the processing of solid foods like meat. Therefore, the current project was designed to assess the impact of PEF processing on beef muscles and its potential use to reduce meat ageing time and cost. Post rigor Biceps femoris (a low value beef muscle) cuts were exposed to PEF (electric field strength of 1.7 - 2.0 kV/cm and pulsed electrical energy of 185 kJ/kg) processing and sampled after aging at 4 oC for 3, 7, 14 or 21 days. Samples were assessed for temperature increases, electrical conductivity, pH, purge loss, cooking loss, tenderness and colour stability. The microstructure of PEF treated and untreated meat samples were also investigated. Our results showed that temperature, electrical conductivity, and pH were significantly (P<0.05) affected by PEF treatment conditions. Tenderness, as indicated by a reduced shear force value, significantly (P<0.05) increased following PEF treatment compared to the untreated samples. Cooking loss was not affected by PEF treatment, whilst purge loss significantly (P<0.05) increased after PEF treatment and during ageing. The PEF treated meat samples showed a dramatic increase in the number of myofibrils ruptured along the z-lines compared to the untreated samples during ageing. This resulted in beef muscle with a more porous structure compared to the untreated samples and accounts for the observed increase in electrical conductivity and purge loss. These results suggest that PEF induces changes in the microstructure and texture of meat and could potentially be used to improve tenderness, decrease ageing time or to alter functional properties.