This recipe was devised when I had a lot of limes on hand. I’m sure you could use any citrus fruit you like. The key is using healthy ingredients! This muffin is a moderately sweet breakfast treat but much healthier than sweet cereal. The coconut oil is very healthy for you, and so is the flaxseed. Never use margarine! Always use non-aluminum baking powder. I use white whole wheat flour, it comes from white wheat instead of red wheat. These are always a hit at my house.