The purple sweet potato stuffing in moon cakes is usually made of fresh purple sweet potatoes, and chemical additives such as preservatives are not added. This is because purple potato itself has certain freshness and can be preserved for a certain period of time. If you fry the purple sweet potato stuffing yourself and don't add preservatives and other additives, the storage time will be relatively short. The homemade purple sweet potato stuffing can be preserved for about 3 to 5 days. If it is sealed and packaged, the storage time can be extended to about 1 days. Because there is no protection of additives, it is recommended to finish eating as soon as possible in order to ensure the freshness and safety of food. If the storage time is too long, the purple sweet potato stuffing will deteriorate or lose its taste and flavor.