Royer Aurélien, Daux Valérie, Fourel François, Lécuyer Christophe
Biogéosciences, Université de Bourgogne Franche-Comté, UMR CNRS 6282, EPHE, PSL Research University, 6 Boulevard Gabriel, Dijon, 21000, France.
PACEA, UMR CNRS 5199, Université de Bordeaux, Ministère de la Culture et de la Communication, Pessac, 33615, France.
Am J Phys Anthropol. 2017 Aug;163(4):759-771. doi: 10.1002/ajpa.23246. Epub 2017 Jun 12.
Stable isotope data provide insight into the reconstruction of ancient human diet. However, cooking may alter the original stable isotope compositions of food due to losses and modifications of biochemical and water components.
To address this issue, carbon, nitrogen and oxygen isotope ratios were measured on meat aliquots sampled from various animals such as pork, beef, duck and chicken, and also from the flesh of fishes such as salmon, European seabass, European pilchard, sole, gilt-head bream, and tuna. For each specimen, three pieces were cooked according to the three most commonly-known cooking practices: boiling, frying and roasting on a barbecue.
Our data show that cooking produced isotopic shifts up to 1.8‰, 3.5‰, and 5.2‰ for δ C, δ N, and δ O values, respectively. Such variations between raw and cooked food are much greater than previously estimated in the literature; they are more sensitive to the type of food rather than to the cooking process itself, except in the case of boiling.
Reconstructions of paleodietary may thus suffer slight bias in cases of populations with undiversified diets that are restrained toward a specific raw or cooked product, or using a specific cooking mode. In cases of oxygen isotope compositions from skeletal remains (bones, teeth), they not only constitute a valuable proxy for reconstructing past climatic conditions, but they could also be used to improve our knowledge of past human diet.
稳定同位素数据有助于深入了解古代人类饮食的重建。然而，烹饪可能会因生物化学成分和水分成分的损失及改变而改变食物原本的稳定同位素组成。
为解决这一问题，对从各种动物（如猪肉、牛肉、鸭肉和鸡肉）以及鱼类（如三文鱼、欧洲鲈鱼、欧洲沙丁鱼、鳎鱼、金头鲷和金枪鱼）的肉中采集的样本进行碳、氮和氧同位素比率测量。对于每个样本，按照三种最常见的烹饪方法（煮、煎和烧烤）烹饪三块样本。
我们的数据表明，烹饪使δC、δN和δO值的同位素偏移分别高达1.8‰、3.5‰和5.2‰。生熟食物之间的这种差异比文献中先前估计的要大得多；除煮的情况外，它们对食物类型比对烹饪过程本身更敏感。
因此，在饮食单一的人群中，如果他们局限于特定的生或熟食物产品，或使用特定的烹饪方式，那么古饮食的重建可能会有轻微偏差。对于骨骼遗骸（骨头、牙齿）的氧同位素组成而言，它们不仅是重建过去气候条件的有价值指标，还可用于增进我们对过去人类饮食的了解。
