ABSTRACT: Phylloquinone (vitamin K1) is the primary dietary source of vitamin K. Processing effects and stability of phylloquinone were investigated during juice and concentrate production from sea buckthorn (Hippophaë rhamnoides) using berries from 2 different growing areas. During industrial juice production the technological processing of the berries caused a loss of about 36% to 54% phylloquinone in the generated juice. The following processing steps leading to the concentrated juice resulted in a complete depletion of phylloquinone. Sea buckthorn berries and juice were stored at 6, 25, and 40 °C for up to 7 d to determine the temperature effects on phylloquinone during storage. Content of vitamin K1 in sea buckthorn berries was affected by storage time and storage temperature. Storage of freshly harvested berries resulted in a significant increase (P < 0.01) of phylloquinone ranging from 21% up to 186% (wet weight). The juices showed almost identical significant degradation (P < 0.01) of phylloquinone of about 18% to 32% at 6, 25, and 40 °C indicating that intensity of decomposition is independent of temperature (6 to 40 °C) and storage time in the range of consumer storage conditions.