The present invention relates to processes for the production of arachidonic acid containing oils, which preferably are substantially free of eicosapentaneoic acid. The invention also relates to compositions containing oils having very high amounts of arachidonic acid in triglyceride form, and to uses of such oils. In a preferred embodiment, Mortierella alpina is cultivated using conditions which yield triglyceride oil having particularly high levels of arachidonic acid residues, biomass is harvested and the oil is extracted, recovered, and used as an additive for infant formula.The present invention relates to processes for the production of arachidonic acid containing oils, which preferably are substantially free of eicosapentaneoic acid. The invention also relates to compositions containing oils having very high amounts of arachidonic acid in triglyceride form, and to uses of such oils. In a preferred embodiment, Mortierella alpina is cultivated using conditions which yield triglyceride oil having particularly high levels of arachidonic acid residues, biomass is harvested and the oil is extracted, recovered, and used as an additive for infant formula.본 발명은 바람직하게는 사실상 에이코사펜타엔산을 함유하지 않는 아라키돈산 함유 오일을 제조하는 방법에 관한 것이다. 또한, 본 발명은 트리글리세라이드의 형태로 매우 높은 양의 아라키돈산을 갖는 오일 함유 조성물 및 이러한 오일의 용도에 관한 것이다. 바람직한 양태에서, 모르티에렐라 알피나는 특히 높은 수준의 아라키돈산 잔기를 갖는 트리글리세라이드 오일을 제공하는 조건을 사용하여 배양하고, 바이오매쓰를 수거하고, 오일을 추출하고, 회수한 다음, 분유 첨가제로서 사용한다.