2. Auricularia auricula is a commonly used cold food. When we eat Auricularia auricula, we usually soak it first. However, auricularia auricula can't be soaked for a long time, so we should pay attention to the control of time in the process of soaking auricularia auricula. This is because auricularia auricula will be invaded and propagated by bacteria and mold for a long time. At this time, auricularia auricula has been polluted and easily deteriorated, thus producing biotoxins.