The Basic Study of Lipids Remained on Ancient Pottery

2002 Fiscal Year Final Research Report Summary

• Project/Area Number: 11680164
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Cultural property science
• Research Institution: International Christian University
• Principal Investigator: HORIUCHI Akiko International Christian University, Department of Chemistry Assistant Professor, 教養学部, 助教授 (60052289)
• Project Period (FY): 1999 – 2002
• Keywords: lipid / glyceride / fatty acid / cholesterol / phytosterol / gas chromatography / archaeology / pottery

Research Abstract

In order to investigate the life style and environment of ancient people from lipids remained on ancient pottery, the reliability of analytical results is crucial. Accordingly, we have collected, analyzed and discussed the basic data on how lipids, adsorbed on pottery models, changed with time under various environments. In 1999 and 2000, the research was focused on fatty acids (FA) and glyerides, and in 2001, sterols were studied. These lipids of known composition were adhered to the pottery model and left in air, in sealed tube, buried in soil and in water (2001) for maximum of 1650 days. The lipids were recovered at certain time intervals and changes of lipids were monitored. From these results, we have found that lipids migrate to the inner part of the pottery with time and trapped within the matrix of the pottery. Therefore, from 2000 on, lipids were recovered from the surface as well as from inner portion of the pottery. In the final year (2002), lipids were extracted from Jomon pottery (Kastusaka type , and Kasori type E), and sterols were analyses
Results: (1) Triglycerides (TG) were slowly decomposed to FA with time. (2) FA compositions changed under all conditions. (3) TG adsorbed deep inside the pottery maintained its composition relatively well especially if kept in the sealed tube or in water (155 days). (4) The ratio of pytosterols (campesterol, stigmasterol, β-sitosterol) and animal cholesterol remained constant within acceptable error under all conditions (45days). (5) Sterols were detected from the extract of Jomon pottery, but since amount was very small, the efficient method to hydrolyze sterol esters was developed, and detectable sterols were increased significantly. (6) Cholesterol, campesterol, stigmasterol, β-sitosterol were detected from Jomon pottery. The ratio of pytosterol/cholesterol differed between extracts from inner and outer pottery of deep dish, probably caused by cooking process, but the ratio was similar for shallow dish used for serving