Using High-pressure Processing to Improve the Quality of Dark-cutting Beef

Previous studies have shown high-pressure processing (HPP) can be utilized to improve lean color of dark-cutting beef color by increasing the lightness and redness of steaks. However, the optimal parameters of length of time product is held under pressure and at which pressure must be applied have yet to be fully defined. Furthermore, the impact of HPP on color labile muscles in dark-cutting beef are currently unknown. Therefore, two studies were designed and specific efforts were focused on first defining optimal parameters for color stable muscles, followed by determining the effect of HPP on dark-cutting color labile muscles. In the first study, pressures of 300 and 450 MPa were shown to be effective at increasing the lightness and redness of dark-cutting steaks regardless of holding time. A pressure of 240 MPa was also implemented but showed limited effects. On the other hand, steaks subjected to the 450 MPa pressure presented a pale and negative visual appearance, the greatest surface discoloration, and lipid oxidation for the higher holding times (30, 60, and 90 s; P < 0.05). In the second study which examined HPP impact on dark-cutting color labile muscle (Psoas Major), pressures of 300 and 450 MPa resulted in increased lightness (L*) and yellowness (b*) but decreased redness (a*) in treated steaks. The 450 MPa treatment group had the most impact with the greatest lightness, lowest redness, and increased lipid oxidation. Furthermore, HPP treatment resulted in greater surface discoloration, higher color scores and greater paleness (P < 0.05). Advisors: Gary A. Sullivan and Jordan C. Wicks