1, Improper preservation: All kinds of materials in Gongcheng Camellia oleifera are easy to get wet or deteriorate, and if Camellia oleifera is not properly sealed and kept dry, it will cause rancidity. Humid environment is conducive to the reproduction of microorganisms, resulting in moldy food or odor.

2. Bacterial growth: Poor sanitary conditions during the production of Gongcheng Camellia oleifera will lead to bacterial growth and rancidity.

3. Too long time: After the Gongcheng Camellia oleifera is correctly preserved, it will also develop the characteristics of sour export after a long time.