Effect of Electrostatic Field Assisted Thawing on the Quality of Previously Frozen Beef Striploins

Abstract

The objective of this study was to evaluate the impact of applying electrostatic field (EF)–assisted thawing on the quality attributes of previously frozen beef striploin. Beef striploins from both sides of 12 USDA Choice carcasses were halved, frozen at −40°C, and thawed under 4 EF voltage treatments: 0 kV (control), 2.5 kV, 5 kV, and 10 kV. After reaching the internal temperature of −1°C, striploins were weighed for yield calculation, swabbed for microbial analysis, fabricated into steaks, and assigned to either 0- or 14-d aging period and retail displayed for 0 or 7 d. Subjective and objective color measurements were taken during the retail display. Upon completion of retail display, Warner-Bratzler shear force (WBSF), cook loss, sarcomere length, troponin-T degradation, muscle fiber spacing, lipid oxidation, antioxidant capacity, pH, and proximate analysis were performed. All EF treatments increased purge loss compared to the control (P<0.05) and did not improve thawing speed, with samples from 10 kV actually taking the longest to thaw (P<0.05). The 2.5 kV and 5 kV samples aged 14 d showed less discoloration than those from 0 kV and 10 kV, and 5 kV samples aged 14 d had higher a* than those from the other treatments (P<0.05). Samples thawed under 10 kV showed a reduction in WBSF compared to the control (P<0.05), but there was no impact of EF on aerobic plate count, sarcomere length, troponin-T degradation,relative fat %, crude protein %, moisture %, purge protein concentration, pH, lipid oxidation, or antioxidant capacity for either the hydrophilic (water soluble) and lipophilic (lipid soluble) portion of the samples (P>0.05). Overall, our study determined that there was no economic benefit to apply EF during thawing regarding yield and purge loss. However, the application of EF may improve tenderness and extend shelf life of beef during retail display.