Abstract: In order to explore changes in mitochondrial function and structure during the chilled storage of beef, the mitochondrial damage was evaluated by observation of the internal and external ultrastructure of mitochondria using transmission electron microscopy and atomic force microscopy. With the increase of storage time up to 21 d, Flameng score was increased from 0.986 8 to 2.533 8, indicating that the mitochondrial structural integrity gradually decreased; there were significant positive correlations between mitochondrial membrane potential and mitochondrial respiratory control ratio and ATP content with correlation coefficients of up to 0.936 and 0.926 (P < 0.01), reflecting the close relationship between mitochondrial structure and function. Moreover, mitochondrial respiratory control ratio was significantly positively correlated with the relative content oxymyoglobin (r = 0.885, P < 0.01), while mitochondrial membrane potential was significantly negatively correlated with the relative content of metmyoglobin (r = 0.902, P < 0.01), indicating that changes in mitochondrial structure and function are closely related to meat color stability.

Key words: chilled beef, atomic force microscopy, transmission electron microscopy, mitochondrial damage