Whisk egg whites, cream of tartar and 50g sugar until just stiff.
Whisk egg yolks and 100g sugar until light and fluffy. Add orange juice and stir in corn oil to blend.
Stir in flour and baking powder to mix.
Carefully and gently add egg yolk mixture into egg white mixture and mix. Pour mixture into an ungreased 21cm chiffon tube pan. Bake in preheated oven at 180 ºC for 40-45 minutes or until cake is cooked when tested with a skewer.
Remove cake from oven and invert immediately. Leave to cool, then remove cake from pan. To do this, run a thin bladed knife around the sides and bottom of the tube pan.