I watched a programme on Foxtel recently which looked at E numbers. This particular episode was about emulsifiers and stabilisers.
Interestingly, Ice Cream was discussed. It seems that to get that luscious creaminess without the large ice crystals, you need to use a stabiliser. Stabilisers are pretty basic gums. Carageenan is one and is made from seaweed, often called Irish Moss. Another is Xanthan. Lecithin is the emulsifier of choice, keeping the fats in the cream linked to the water in the milk.
I might just do some experimenting this weekend as I have those gums as well as lecithin.