Collaboratrici e collaboratori

Vitamin K2 (menaquinone; MKn) has been assessed in some varieties of cheese, but data are limited and do not account for factors like seasonality that affect MKn. To investigate variation of MKn content in cheese, we assayed 121 cheese samples from 10 cheese varieties made from cows', goats', and ewes’ milk throughout an entire production year. The concentrations of MKn species MK-4 to MK-10 were determined using high performance liquid chromatography (HPLC). MKn in the cheese ranged from 23 to 1312 mg kg-1. The highest levels of vitamin K2 are found in Raclette, Vacherin Fribourgeois and Emmentaler. An important determinant of MKn content were the bacterial strains used in the starter cultures. Scalding temperature also influenced MKn content by affecting the survival of MKn-producing strains. Seasonal variability was observed for some cheese varieties, while fat content negatively correlated with total MKn. Based on our results, in Switzerland 13 to 17% of the recommended daily intake for MKn is met by cheese consumption.