China has a 9000-year-long history of cereal-based alcohol production, with the use of molds (filamentous fungi) likely being one of the earliest fermentation techniques. This method later developed into the uniquely East Asian qu (koji) starter compound, containing grains, molds, yeasts, and bacteria. Recent studies have revealed that this method was already widely applied during the Neolithic period. However, much less is known about its development during the early dynastic times, and our knowledge of this innovation has mainly relied on textual materials. Here, we present direct evidence, based on microbotanical, microbial, and chemical analyses, for the fermentation method of a 2300-year-old liquid preserved in a sealed bronze bottle unearthed in a Qin tomb at Yancun, Shaanxi. The results of this research suggest that this liquid is likely a fermented beverage made from wheat/barley, rice, Job’s tears, broomcorn millet, and pulses. The fermentation starter may have been a cereal-based qu, consisting of a wide range of microorganisms, including molds (Aspergillus and Monascus), yeasts, and bacteria. Our findings suggest that the tradition of selecting suitable grains and microbial communities for brewing alcohol, possibly with a maiqu starter (primarily wheat/barley-based qu), may have been well established more than two thousand years ago.

The Liao Dynasty’s highly developed textile industry was characterized as “the best in the world” in ancient Chinese literature. This study analyzed two textiles on a 蹀躞 (DieXie) belt excavated from the No.1 Liao Dynasty noble tomb of Zhangjiayao Forest (Shenyang, China), with one wrapping around the leather belt (T1) and the other on the surface of a leather pouch hanging on the belt (X1). They were identified as silk based on structures by morphological observation and chemical components revealed by Fourier Transform Infrared spectroscopy (FTIR). Proteomics and enzyme-linked immunosorbent assay (ELISA) were used to investigate the animal origin of the silk, and the original color and dyestuffs of T1 were examined by liquid chromatography-mass spectrometer (LC-MS/MS). The results have shown that T1 consists of three layers of Bombyx mori silk plain fabric, and its original color was yellow-red dyed with madder and plants containing flavonoid dyeing tissue, consistent with the color of DieXie belts recorded in the ancient literature. The silk on the pouch is a layer of plain fabric, while the upper layer is embroidery on the Four-end-complex gauze, which was made of twisted Bombyx mori silk. We believe that the silk wrapping around the leather belt was to provide additional comfort and aesthetics after dyeing while protecting the leather, which is prone to warping and moisture. This study suggests that such silk fabrics with high specifications are one of the manifestations of the distinguished status of the tomb owner. The integration of various analytical methods on ancient silk fabrics enables us to learn various information about their textile forms, silk animal origins, colors and dyestuffs, revealing the highly developed silk waving techniques and prosperous costume culture of the Liao Dynasty.

Natural aging plays a key role in the degradation of proteinaceous binders which are important dispersers and stabilizers of painting layers. Knowledge about the natural aging influence on the stability of binders is important for exploring the deterioration mechanisms of painted artworks. Pig glue, whole egg, egg white, egg yolk, casein, and mixtures with ultramarine were aged for 10 years in natural conditions. GC-MS and FTIR were applied to explore the changes in the binders at a molecular level. Our experiment revealed that the less stable Met (Methionine), Lys (Lysine), Ile (Isoleucine), Ser (Serine), Asp (Aspartic acid), Glu (Glutamic acid), Hyp (Hydroxyproline), especially aromatic Phe (Phenylalanine), and Tyr (Tyrosine) were damaged, thus the contents of the stable Ala (Alanine), Gly (Glycine), Val (Valine), Leu (Leucine), and Pro (Proline) increased. The broadening of Amide A and the declining amount of α-helix, along with the increasing contents of β-sheet and random coils, all showed that the binders had transformed into disordered states. What is more, we found that pig glue had better natural aging resistance, ultramarine could speed up the aging process and lipids in egg were more easily degraded. The mechanisms of the changes of primary structures and secondary structures are also discussed in the paper.

The transport and crystallization processes of chromogenic 5.0% CuSO₄ solution in the supporting body and coarse plaster of simulated wall painting samples were observed. A scanning electron microscope a and self-designed double-layer surface contact internal pressure method were used to test, respectively, the micro-morphologies of salt crystals in different regions and the micro-forces on the contact surfaces during the spread and crystallization of water and salt solution. The results demonstrate that the salt crystals formed by the CuSO₄ solution on the surface of the simulated wall painting showed two different shapes: a salt belt formed by clustered crystals, and a layer of salt crust. The difference was speculated to be related to the crystals’ growth conditions. The destructive effect of salt solution and salt crystals on wall paintings manifested itself by weakening the connectivity between different materials, and changing the volume and morphology of the wall paintings. Using the double-layer surface contact internal pressure method, the forces generated by the salt solution and salt crystals on the simulated wall paintings were demonstrated to be adsorption force, expansion force generated by the crystals’ precipitation and growth, and suction force resulting from water loss and the shrinkage of crystals. The expansion force and suction force were not in a stable state, resulting in the contact surfaces continuously bending and stretching. Compared with pure water, salt solution can aggravate damage to the stability of wall paintings. This analysis of the transport, crystallization and micro-forces of a chromogenic salt solution in simulated wall painting samples can provide a scientific basis for studying the general patterns of damage caused by soluble salt to wall paintings during its transport and crystallization, and provide insight that can further the protection of cultural relics.