Figure 1.

PCA analysis of beef LL muscle during postmortem aging at 4 °C (days 0, 0.5, 1, and 2). PCA is made by all the peak ions. The clustering degree of QC samples reflects the repeatability of the experiment. In the score plot, the green, dark blue, purple, and orange dots represent the sample group at days 0, 0.5, 1, and 2 during postmortem aging, respectively. The blue dots represent the QC samples.