Maize consumption in pre-Hispanic south-central Andes: chemical and microscopic evidence from organic residues in archaeological pottery from western Tinogasta (Catamarca, Argentina)

Pre-Hispanic Andean societies depended economically on the cultivation of maize (Zea mays), the main staple food crop in the region after its introduction from highland Mexico. Here we report new data from residue analysis of potsherds recovered in archaeological sites in western Tinogasta, Catamarca province, Argentina, ca. 3rd to 16th centuries AD. Molecular and isotopic (δ13C values) compositions of fatty acids and microscopically identified maize starch granules from organic residues absorbed in archaeological potsherds were compared with Andean ingredients and food residues obtained from experimental replica pots, where traditional recipes were cooked. Complex mixtures of lipids and starch remains observed in archaeological cooking pots indicated combinations of Andean ingredients such as llama, beans, algarroba, and maize, and suggest continuity in the domestic foodways through time. The distribution and δ13C values of lipids preserved in vessels used for alcoholic beverage preparation, storage and transport in Inka sites suggested the possible consumption of two drinks with distinct patterns: traditional Andean maize beer (chicha) and a local fermented drink made from algarroba flour (aloja). This is potential evidence for consumption practices in festive contexts sponsored by the Inka state.