Vitamin K2 in different bovine muscles and breeds

• Vitamin K1 and K2 were quantified in three bovine muscles from two different breeds.
• Longissimus dorsi contained more vitamin K2 than Psoas major.
• Muscles from Jersey had higher levels of vitamin K2 than Norwegian Red.
• Amount of vitamin K2 was not correlated with intramuscular fat or WB shear force.

Meat is a natural source of vitamin K, a vitamin associated with reduced bone loss and prevention of osteoporosis. Whether vitamin K content varies between breeds and muscles in cattle is not known. In the present study, contents of vitamin K1 (phylloquinone) and K2 (menaquinone, MK) were analysed in three different muscles from steers of two different breeds, Norwegian Red and Jersey, respectively. Results showed that MK4 was the most dominant of the vitamin K2 analogues, while only traces were found of MK6 and MK7. Both breeds had higher levels of MK4 in M. biceps femoris (BF) and M. longissimus dorsi (LD) compared to M. psoas major (PM). The results also showed significantly higher MK4 levels in muscles from Jersey compared to Norwegian Red. Furthermore, MK4 was not associated with intramuscular fat, suggesting a physiological role for MK4 in skeletal muscle cells. There were no association between vitamin K content and tenderness.