Significant differences were found between the sampling days within each of the three treatments for deoxymyoglobin. All three treatments fluctuated between 10% and 30% deoxymyoglobin throughout the trial. The N_MAP did not show a higher percentage deoxymyoglobin because there was more than 0.05% O2 in the headspace, resulting in the myoglobin being oxygenated and oxidised. The oxymyoglobin percentage did not increase as expected in the O_MAP, possibly because the high final pH caused the muscle fibres to swell, restricting oxygen penetration, thereby delaying oxygenation and the formation of oxymyoglobin. As seen in Fig. 3, the percentage oxymyoglobin changed significantly over the course of the trial, gradually increasing from approximately 30% on day 0 to >50% on day 6 for all the treatments, with a slight decrease on day 4 in the N_MAP. This indicates that the myoglobin was initially oxygenated and gradually oxidised to metmyoglobin, as the activity of the metmyoglobin reducing enzyme system decreased (Brown & Mebine, 1969). There were no fixed trends in the percentage metmyoglobin in any of the treatments. However, the percentage metmyoglobin remained well below the 70% margin for all treatments, the theoretical point of rejection by a consumer (Daun et al., 1971). Although the data on myoglobin redox states is not conclusive regarding the rate of myoglobin oxidation, it opens the field to further investigation.