Rice

Rice contains spores of Bacillus cereus, a bacterium that can survive even at low temperatures. When rice is cooked and then left at room temperature or kept in the refrigerator for too long, these spores can multiply and produce toxins that are resistant to high temperatures. This makes reheating stored rice risky and potentially harmful.
Additionally, refrigeration can alter the texture and taste of cooked rice. Cold temperatures cause the starches in rice to harden and become less tender.