Søren Krogh Jensen graduated as MSci in 1987 from the Royal Veterinary and Agricultural University in Copenhagen and received his PhD in Biochemistry from the same University in 1991. Since 1991 he has worked at Department of Animal Science, Aarhus University (Formerly the Danish Institute of Agricultural Sciences) with research within animal nutrition with special emphasis on fat soluble vitamins, antioxidants, lipids and lipid oxidation in relation to nutrition, animal product quality and animal health. Special attention has been paid to biochemical and physiological aspects the importance of fat, fatty acids, fat-soluble vitamins (including their antioxidative properties), as well as the physiological importance of anti-nutrients in rapeseed and legumes. Over the years Dr. Jensen has been involved in projects related to utilisation of naturally occurring vitamins in plants by pigs and cattle – also in relation to organic farming. Special focus is on elucidating the difference in the biological value of natural versus synthetic vitamins. In this connection, relatively simple and fast methods capable of separating stereoisomers of α-tocopherol has been implemented based on chiral HPLC. Likewise an HPLC method for analysis of Vitamin D metabolites in plasma and feed has been developed. Recently the research area has shifted to also comprise development and evaluation of new sustainable protein sources.