Assertion: parchment | /r/HasProperty | absent
Facets:
value: in collagen
type: OTHER
Source sentences:
text: Spectra of collagen and parchment are similar, with few exceptions such as the absorption at 1031 cm−1 in parchment which is absent in collagen; this can be assigned to aromatic C–C vibrational modes in tannins, and has been proposed as a marker for tannin-processing of parchment .