Hydrothermal shrinkage behavior of pigskin

The present work focuses on in situ studying the transformation process of collagen molecules and fibrils in pigskin along with hydrothermal shrinkage. The results indicate that the triple helix of collagen molecules is firstly destabilized by hydrothermal treatment and more water molecules enter the space of three polypeptide chains of collagen molecules to slight increase the diameter of collagen fibrils. Then, the thermally labile domain of collagen molecules unfolds first to form tiny nodules. The nodules are shrinkage foci, which enlarge further and finally coalesce resulting in the shrinkage of pigskin. During the shrinkage process, the diameter of fibrils increases sharply. The spaces between collagen fibrils and fibers are compressed to form a more compact space arrangement than original extended forms, resulting in extrusion of water molecules. After shrinkage, partial fibrils structure was still observed and retained their characteristic banding patterns. Subsequently, the residual fibrils structure gradually disappeared and degraded.

Automated summary

The study found that hydrothermal treatment destabilizes the triple helix of collagen molecules, leading to an increase in fiber diameter and subsequent shrinkage of pigskin. During the shrinkage process, the spaces between fibers are compressed, forcing water molecules to be extruded. After shrinkage, the original fiber structure gradually disappears and degrades.