What does the red dot on the rice cake look like?

Like mildew. The main reason for redness is that glutinous rice flour for making rice cakes contains less protein, which is easy to be infected by specific bacteria. After mild infection, the rice cake will appear red mildew spots, and in severe cases, it will smell of alcohol. The rice cake is a traditional food of Han nationality in China, which belongs to the seasonal food of the Lunar New Year.