Published online by Cambridge University Press: 01 June 2009
High-performance liquid chromatography was used to determine the amounts of all-trans retinol, 13-cis retinol and β-carotene in butters on sale in Britain. Samples originating in England and Ireland, New Zealand, Denmark and The Netherlands, and in France were analysed and each type of butter was measured in each season of the year. Fat, water, N and Na contents were also determined. The influence of season and country of origin on vitamin A content and on the level of salting are discussed.