Autoxidation of lipids in parchment

Abstract

Historic parchment is a macromolecular material, which is complex due to its natural origin, inhomogeneity of the skin structure, unknown environmental history and potential localised degradation. Most research into its stability has so far focussed on thermal and structural methods of analyses.Using gas-chromatographic analysis of the atmosphere surrounding parchment during oxidation, we provide the experimental evidence on the production of volatile aldehydes, which can be the products of lipid autoxidation. Oxidation of parchment with different aldehyde emissions was additionally followed in situ using chemiluminometry and the same techniques were used to Building on this evidence, we can conclude that the presence of lipids (either initially present in the skin or resulting from conservation intervention) leads to oxidative degradation of collagen and that the non-destructive analysis of the emission of volatiles could be used as a quick tool for evaluation of parchment stability.

Raman spectroscopic analysis of an important Visigothic historiated manuscript

“…The shoulder at 1711 cm −1 and the band at 1375 cm −1 can be attributed to ν(C=O) and ν(CH) modes of lipids, respectively. These bands may well be the result of lipid oxidation as recent studies hypothesized that oxidation of parchment lipids could lead to collagen degradation [47].…”

On oxidative degradation of parchment and its non-destructive characterisation and dating

“…In terms of material stability, hydrothermal properties of parchment are of major interest and much research has so far been focused on thermal and structural methods of analysis. However, studies of historic materials are difficult due to unknown storage history, production methods and inhomogeneous composition and structure [7], and techniques from macro to nanoscale may be necessary [8]. Shrinkage temperature has been reported to be a good indicator of hydrothermal stability, and indicative of the level of deterioration of collagen fibres [9,10].…”

“…It was recently shown that lipid content in parchment may have an important influence on collagen degradation [4], probably via autoxidation [7]. In the oxidation processes of skin tissue, protein, carbohydrates and lipids are all targets for reactive oxygen species (ROS) [17,18].…”

“…In the oxidation processes of skin tissue, protein, carbohydrates and lipids are all targets for reactive oxygen species (ROS) [17,18]. During the process of reaction of proteins with reactive oxygen species, an increase of carbonyl groups in the protein macromolecule was detected, indicating degradation of the peptide chain [7]. On the other hand, changes in the structure of collagen may be indirectly caused by autoxidation of carbohydrates and lipids [7,17,18].…”

Smell of heritage: a framework for the identification, analysis and archival of historic odours

“…GC-MS techniques are routinely used to analyse perfumes and cosmetic preparations [41]. SPME-GC-MS as used in this paper has been specifically optimized for analysis of the headspace of objects made of organic materials, such as book and paper [33], leather and parchment [42] and has been successfully used to sample air in libraries [43]. Recent research shows that the profiles of volatile organic compounds found in historic libraries can be directly linked to the emissions from decaying books and wood furnishing [43], which makes it reasonable to assume that sampling VOCs both from books and from library environments can be done using the same technique, i.e.…”