New alternatives for improving and assessing the color of darkcutting beef a review

ABSTRACT

ABSTRACT Myoglobin (Mb) is a sarcoplasmic heme protein present in muscle cells, which acts as a shortterm oxygen (O2) reserve in the muscle tissue. After slaughtering and exsanguination, Mb is the major pigment that provides the red color in meat. The concentration of Mb together with its redox state are two pivotal factors that determine meat color. The elevated pH of darkcutting beef can affect both physical and biochemical properties resulting in decreased oxygenation. The darkening observed in high ultimate pH (pHu) beef concerns meat processors as color is the initial attribute that impacts on the purchase. Thus, any atypical meat color (i.e., loss of brightness) reduces consumer interest in the product. Several studies have demonstrated that immunological castration is effective in preventing both aggressive behavior and undesirable darkcutting of bull meat. However, little information is available on the effects of processing techniques that limit the oxidation of ferrous iron (Fe2+), Mb or promote metmyoglobin (MMb) reduction in darkcutting beef. Because of the importance of color to fresh beef marketability, this review aimed at overviewing the significance of pHu in beef color and color stability and to discuss new alternatives for improving and assessing the beef color of darkcutting beef, especially in Nellore bulls and their crossbreds, which are widely used in beef cattle production in Brazil.