1. If there are small spots on the surface of sea cucumber, this is normal. There is a well-made dry sea cucumber called "Mantianxing", and it is normal that there are sparse white spots on the surface of sea cucumber (as shown below 1).
Figure 1: light dry sea cucumber
2. If it's all-white granules like Figure 2, it's salt dry sea cucumber with extremely high salt content, so it's not recommended to eat.
Figure 2: Salt dry sea cucumber