02290nas a2200229   4500008004100000245013700041210006900178300001400247490000700261520154500268653002201813653001501835653001101850653002001861653002001881653003501901100001801936700002101954700002001975700001701995856004802012       2011                        eng d00aHardwood Ash Nixtamalization May Lead to False Negatives for the Presence of Maize by Depleting Bulk delta13C in Carbonized Residues0 aHardwood Ash Nixtamalization May Lead to False Negatives for the  a2726-27300 v383 a<p>Among the multiple proxies for detecting maize in precontact economies is the use of δ<sup>13</sup>C analysis of carbonized residues from ceramic cooking vessels. Although maize horticulture was widely established in Eastern North America (ENA) by A.D. 1000, there are carbonized residues from ceramic assemblages after this date that lack the elevated δ<sup>13</sup>C values indicative of the presence of maize. This may be due to the true absence of maize, or other factors including the masking of maize. Prior experimental research by Hart et&nbsp;al. demonstrated that the addition of C<sub>3</sub> plants or consumers to two part mixes with maize can mask maize presence even when maize is the dominant ingredient. Here we investigate the effect of alkali processing of maize (nixtamalization) on δ<sup>13</sup>C using the widespread ENA process of boiling maize kernels with wood ash, a C<sub>3</sub> product, to create hominy. Our experiments test whether or not the process of hardwood ash nixtamalization can mask the presence of maize in adhering carbonized residues by depleting δ<sup>13</sup>C values, and whether there is a reciprocal δ<sup>13</sup>C enrichment effect on the hardwood ash employed in nixtamalization. Overall, there is substantial δ<sup>13</sup>C depletion of residues when maize is cooked with hardwood ash, and hardwood ash cooked with maize shows the reciprocal enrichment. Therefore, the depleted values after the adoption of maize may be false negatives due to the nixtamalization process.</p>
10aAlkali processing10aBulk δ13C10aHominy10aMaize histories10aPottery residue10aPrehistoric cooking techniques1 aLovis, W., A.1 aUrquhart, G., R.1 aRaviele, M., E.1 aHart, J., P.  uhttp://dx.doi.org/10.1016/j.jas.2011.06.010