New Australian research suggests that marbling is not flecks through the meat, but single strips of fat laid down along predictable pathways.
University of Adelaide researchers using 3D image analysis have discovered evidence of marbling as a single, connected network.
Their findings suggest that marbling occurs along an internal pathway, such as blood vessels or the fluid-filled spaces between muscles. “Rather than having dispersed individual flecks of marbling, the intramuscular fat was a single entity,” said lead researcher Cynthia Bottema.
The researchers also discovered that, as marbling increases, the diameter – but not the shape – of the interconnected structure enlarges. “Intramuscular fat appears to be deposited along an existing network,” Dr Bottema said.
The researchers analysed sections of Angus striploins of varied marbling to assess potential differences in intramuscular fat structure. Dr Bottema explained: “Surprisingly, the majority of the intramuscular fat appeared to be connected along the 100mm of muscle in both the highly marbled and less-marbled striploins.
“The main difference was the thicker deposit in the highly marbled striploins. However, the amount of branching in the intramuscular fat did not vary with the level of marbling.”
She added that the patterning was likely to apply across other cattle breeds. “One would assume that the biology of intramuscular fat deposition would be the same across breeds. There is no reason to believe otherwise. So, although the research was performed using Angus striploins, it should apply to all cattle breeds including Waygu,” she said.