Squeeze excess liquid from the capers and add to a pot with the cream and lime zest. Bring to the boil and transfer to a Thermomix jug. Set the temperature to 80°C, and blend on high until the custard reaches 80°C, then add the iota carrageenan. Blend for another minute to activate the iota carrageenan, and then place in the fridge to cool.
Transfer to the blender and blend for another