High Pressure–Induced Changes in Meat Color

Abstract

High pressure (HP) treatment of meat affects the color of beef, lamb, pork, and chicken meat in similar ways and often results in discoloration. The physical and chemical state of the meat, especially myoglobin, and the surroundings during pressurization determine the extent of color changes. The main part of the pressure-induced color changes is related to the red myoglobin molecule. Thus, the reduction of the redness is accounted for either by myoglobin denaturation and/or heme displacement as well as oxidation of the bright red oxymyoglobin to the brownish metmyoglobin. This effect is obviously more pronounced for the high myoglobin beef meat compared to the white chicken meat. Pressurization of meat also causes an increased lightness and, thereby, an increase in the L∗-value, due to the denaturation of the myofibrillar proteins. Denatured proteins more easily aggregate promoting changes of the meat surface, consequently increasing the amount of reflected light, which appears as the lightening color effect. In conclusion, the pressure-induced color change is due to both the modification of the myoglobin molecule and changes in the meat microstructure.