Assertion: sepia melanin | /r/HasProperty | black powder
Facets:
Source sentences:
text: Purified sepia melanin is a black powder, hygroscopic that should be refrigerated at -20°C to avoid decomposition .
text: This purified sepia melanin is a black powder, hygroscopic that has been kept refrigerated at - 20° C to avoid any photo-chemical of photo-physical alterations.