A Review of the Chemical Structure, Applications and Methods of Identifying Casein Adhesives in Historical Properties

Casein is one of the proteins that have been used historically, and traces of its use have been visible throughout history. Casein is extracted from mammalian milk, especially cow's milk, and is used in works of art such as painting staples, paper slats, wood veneers, additives in gypsum mortars, or as an adhesive in the field of conservation and restoration. This study aimed to introduce the applications of casein, how to make adhesive from this material, the structural properties, and finally, methods and chemical analysis introduced to identify this natural substance in historical works. According to the findings of this study, it was determined: A: casein, hydrated lime, sodium oxides and silicates, metal salts, and water are suitable compounds for making casein glue B: casein structure is more spherical and has a hydrophilic and hydrophobic part which causes waterproofing in some historical works such as paintings. c: instrumental analyzes such as Raman spectroscopy, gas chromatography-mass spectrometry (GC-MS), thin-layer chromatography (TLC), and more chemical methods (Spot test) such as Ninhydrin test and Biore test is applicable to identify proteins, especially casein