Pre- or post-depositional heating of fossil biominerals will impact resulting amino acid dates, but the study on the effects on their amino acids of dry artificial heating of molluscs has not yet been fully tested. Here we report a study on three mollusc species to show how amino acid content can potentially be used to identify archaeological samples that have been subjected to artificial heating. The identification of markers of exposure to high temperature could be useful to reject compromised samples for amino acid racemisation dating. In order to identify markers of heat exposure, we artificially heated modern shell samples belonging to three marine molluscs found in abundance at archaeological sites, namely Patella vulgata, Phorcus lineatus and Littorina littorea. The markers found were compared with data from an archaeological dataset for these three species. Our results indicate that there is unlikely to be a single marker indicating artificial heating of a sample, especially for archaeological samples, which have been exposed to a wide variety of complex conditions that cannot be simulated in an isothermal experiment. However in general, we observed changes in shell composition which were indicative of heating: higher %Glx and %Ala and lower %Asx and %Ser for a given Asx D/L value. Moreover, samples heated at high temperatures showed higher than expected Glx and Ala D/L values for a given Asx D/L value. Likewise, the amino acid content of the shells decreased with heating time and temperature. Furthermore, shells artificially heated at > 300 °C had additional compounds evident in the chromatogram, and a poor baseline, thus causing a loss of resolution of late eluting amino acids. Of note, samples heated at 500 °C (5 min) and 400 °C (10–20 min) preserved negligible amino acid content. Archaeological samples that deviated from the expected unheated trend were therefore identified as having been heated.

化石生物矿物质的沉积前或沉积后加热会影响所得的氨基酸日期，但对软体动物干人工加热对其氨基酸的影响的研究尚未得到充分测试。在这里，我们报告了对三种软体动物物种的研究，以显示如何将氨基酸含量潜在地用于鉴定经过人工加热的考古样本。鉴定暴露于高温下的标志物可能有助于拒绝受损样品进行氨基酸外消旋约会。为了确定热暴露的标志，我们人为地加热属于三个海洋软体动物贝壳现代样品中发现大量的考古遗址，即髌骨vulgata，Phorcus绦虫和滨littorea。将发现的标记与来自这三个物种的考古数据集的数据进行比较。我们的结果表明，不可能有一个单一的标记来指示样品的人工加热，特别是对于考古样品，该样品已暴露于无法在等温实验中模拟的多种复杂条件下。但是，总的来说，我们观察到壳组成的变化指示了加热：对于给定的Asx D / L值，较高的％Glx和％Ala以及较低的％Asx和％Ser。此外，在给定的Asx D / L值下，高温加热的样品显示出高于预期的Glx和Ala D / L值。同样，壳的氨基酸含量随加热时间和温度而降低。此外，在> 300°C的温度下人为加热的贝壳在色谱图中明显还有其他化合物，基线差，导致后期洗脱氨基酸的分离度降低。值得注意的是，在500°C（5分钟）和400°C（10–20分钟）加热的样品保留的氨基酸含量可忽略不计。因此，已将偏离预期未加热趋势的考古样品确定为已加热。