Lime treatments for food preparation identified in Postclassic Xochimilco (Mexico) ceramic sherds

Archaeological evidence from Postclassic Xochimilco, Mexico, reveals that lime treatments were used not only for maize nixtamalization but also to process other plant foodstuffs. Analysis of a whitish layer on ceramic sherds using FT-IR confirmed the presence of calcium carbonate, while binocular microscopy showed multiple microlayers suggesting repeated use. Starch grain analysis identified residues indicating diverse alkaline-treated foods, a practice previously undocumented archaeologically despite its modern prevalence in Mexico.

Hernández-Grajales, M., Barba, L., García-Granero, J. J., Mileto, S., Castillo Mangas, M. T., Mejía Appel, G., & Pecci, A. (2025). Lime treatments for food preparation identified in Postclassic Xochimilco (Mexico) ceramic sherds. Archaeological and Anthropological Sciences, 17(11). https://doi.org/10.1007/s12520-025-02314-3