抄録
The aim of this study is to elucidate and reconstruct paleo diets using the carbon and nitrogen isotope ratios (δ13C and δ15N) of
charred residue on earthenware pots. It is necessary to consider whether there are any significant differences in the δ13C and δ15N
values of modern foods between before and after cooking. In this study, we investigated the changes occurring during the boiling
of foods (sea bream, coho salmon, hard-shell clam, wakame, rice, and millet) in the earthenware pot. In addition, we examined the
fluctuations in δ13C and δ15N values in the charred residue. We defined the cases where δ13C and δ15N values varied by more than 1.0
‰ and 3.0 ‰, respectively, as “varied”. The δ13C “variation” was small within 1.0 ‰ except sea bream which indicated decreases
of 1.4-1.8 ‰. The change in δ15N values was less than 3.0 ‰ in all charred residue samples. The δ13C and δ15N values were likely
to be almost maintained during boiling. This result suggested that δ13C and δ15N values of charred residue depended on the food
group, such as fish, shellfish, seaweed, and C3 and C4 plants. Thus, we may discriminate the food groups of charred residues using
their δ13C and δ15N values.
