Physical and chemical properties
It has been found that vitamin K has the chemical structure similar to naphthoquinone. There are two major forms of this vitamin: vitamin K1 (phylloquinone, phytomenadione, phytonadione) and K2 (menaquinone).
Vitamin K1 is oily liquid, which boils at 20 °C. It is very light sensitive and rapidly decomposes under the action of ultraviolet radiation.
Vitamin K2 is a crystalline substance, which melts at a temperature of 50 to 52 °C
Later is synthesized vitamin K3 (menadione).
Vitamin K is sensitive primarily to X-rays, radiation, aspirin, air pollution, mineral oil. In the frozen food activity of this vitamin can be lost.