Mars subsidiary Masterfoods has been awarded a US patent for its method of preparing puffed cereal cakes. The invention is intended to broaden the range of ingredients that can be incorporated into rice cakes, as currently most edible materials, such as vitamins or chocolate, are degraded by the high temperatures necessary to form them. As a result, rice cakes generally only contain rice and salt, with flavourings added to the surface after forming. Masterfoods claims this has resulted in limited consumer acceptance of rice cakes.