Formation of biogenic amines and vitamin K contents in the Norwegian autochthonous cheese Gamalost during ripening

Gamalost, a Norwegian mould (Mucor mucedo) ripened autochthonous cheese, is a potential functional food due to a high content of peptides that might reduce hypertension, however it has a high content of free amino acids which may be precursors for biogenic amines. This study aimed to investigate if Gamalost might have further health benefits or risks by determination of the formation of vitamin K and biogenic amines. The development of biogenic amines and vitamin K was analysed during ripening. Putrescine was the only biogenic amine detected by liquid chromatography in ripened Gamalost, in the range from 11 to 25 mg.kg(-1). The presence of very low concentrations of biogenic amines may suggest that Gamalost is devoid of hazards posed on health. The menaquinones (vitamin K-2) detected in Gamalost by high-performance liquid chromatography were MK-4 to MK-10 and among them, MK-9 was found in the significantly highest concentration (46 mu g. 100g(-1)). The menaquinone content of Gamalost was attributed to the activities of the starter lactic acid bacteria used for fermentation during manufacture. Gamalost contained a significantly higher menaquinone content than Norvegia, a Norwegian cheese.