The Importance of Understanding Wheat-Based Glues in Historic Bookbinding

The term “bookworm” is often used to describe individuals who love to read, but in the context of historic bookbinding, bookworms take on a more literal meaning. Microorganisms and the passage of time can break down the flour pastes commonly used in old publications to keep them intact. Researchers have delved into the proteins found in wheat-based glues utilized in historic bookbinding to gain insights into their adhesiveness and degradation over time, as detailed in the Journal of Proteome Research.

Ancient civilizations, such as Ancient Egypt, have been known to use wheat-based glues, but little is known about the protein composition of these adhesives. Flour glues are derived from the interior of wheat grains, containing gluten that is appealing to both bookworms and microorganisms. On the other hand, starch glue is produced from the proteins left behind once most of the gluten is extracted, making it less attractive to pests. Understanding the properties of the proteins in these glues and their impact on adhesiveness can assist book conservators in selecting the most suitable methods and materials for preservation work.

Rocio Prisby and her team conducted an analysis of protein profiles for both flour and starch glues, identifying disparities between the two types. They then utilized this data to assess books from the National Library of Medicine (NLM) archives. Through the extraction of proteins from artificially created flour and starch glues and the utilization of mass spectrometry data and bioinformatics software, the researchers determined that flour glue contains a greater quantity and variety of proteins compared to starch glue. Moreover, the proteins present in starch glue exhibited enhanced durability and flexibility, making it a potentially superior option for book restoration projects.

The application of protein profiles enabled the researchers to examine historic bookbinding samples from the NLM archives and confirm the usage of flour-based adhesives based on their gluten content. The detection of degraded gluten in the samples suggested potential damage and a decrease in adhesiveness. Furthermore, the researchers noted that the chemical breakdown of leather and glue in a book’s cover can impact each other, leading to accelerated deterioration. This research offers valuable insights that could alert conservators to the necessity for repairs, thereby safeguarding books from harm or permanent loss. Additionally, the study underscores the potential of protein analysis in informing conservation endeavors on a broader scale.

Understanding the composition and behavior of wheat-based glues in historic bookbinding is essential for the preservation of invaluable literary works for future generations. By unraveling the complexities of these adhesives at a molecular level, book conservationists can make informed decisions that prolong the lifespan of treasured tomes and prevent irreversible damage.