INVESTIGADORES
LANTOS Irene Johanna
congresos y reuniones científicas
Título:
Archaeometric evidence of foodways in the South-Central Andes: Prehispanic maize consumption in West Tinogasta (Catamarca, Argentina)
Autor/es:
LANTOS, IRENE JOHANNA; SPANGENBERG, JORGE E.; GIOVANNETTI, MARCO; MAIER, MARTA SILVIA; RATTO, NORMA
Lugar:
Lausanne
Reunión:
Congreso; 11th Swiss Geoscience Meeting; 2013
Institución organizadora:
Swiss Geological Society y Université de Lausanne
Resumen:
Pre-Hispanic Andean societies depended economically to a large degree on the extensive horticultural production of maize (Zea mays), the main staple food crop in the region. Carbonized maize and maize-based food residues can be identified in archaeological ceramics by a combination of chemical and stable carbon isotope analyses of preserved lipids by the use of bulk and molecular isotopic techniques combining gas chromatography and mass spectrometry (GC-MS, GC-C-IRMS; e.g. Reber & Evershed 2004, Seinfeld et al. 2009). Archaeological finds at the West Tinogasta area in the Catamarca Province, NW Argentina record a long and discontinuous history of pre-Columbian human occupation from early hunter-gatherers to the highly developed Inka civilization in the south-central Andes. Here we report the results of the first chemical and isotopic analyses of organic residues in ceramic potsherds recovered from sites at Tinogasta covering two distinct periods, the Formative Period (450-1020 cal. AD) and the Inka State Period (1400-1550 cal. AD) that overlaps with the first Hispanic contact. The results were compared with reference samples derived from i) typical Andean food products including local maize landraces, beans (Phaseolus vulgaris), algarrobo (Prosopis sp.), and animal fat obtained from native llama (Lama glama) and introduced cattle (Bos taurus), and ii) three replicate test pots used each for cooking traditional Andean maize-based recipes, such as locro, mazamorra and pochoclo. The extracted lipids were analysed by TLC, GC-FID, GC-MS and GC-C-IRMS. The reference food products showed a high concentration of triacylglycerols (TAG), low concentrations of diacylglycerols (DAG), monoacylglycerols (MAG) and free fatty acids (FFA), and significant amount of sterols. Relatively high amount of lipids were recovered from the test pots (up to 18 mg/g) and the Tinogasta potsherds (0.5 mg/g). The test pots had higher concentration of DAG, MAG and FFA than the food products, due to degradation during cooking. The archaeological samples had mainly FFA and sterols, with low amounts of partially hydrolysed acylglycerols, most probably due to degradation at the burial site. Andean maize landraces have similar fatty acid methyl ester (FAME) profiles to those of commercial maize species, with high levels of oleic (18:1) and linoleic (18:2) acids. The FA distributions in the archaeological samples compare favourably to test pots, and are typical of degraded mixtures of vegetable oils (18:2) and animal fats (myristic and stearic acids; 14:0, 18:0). Polyunsaturated acids tend to disappear in more degraded samples. Differences in the FA profiles within the archaeological samples set suggest that various types of food products were stored/cooked in the pots. The δ13C values of the main fatty acids in 22 archaeological samples were compared with those of the references samples (symbols and fields in Figure 1). The Tinogasta samples plot between the fields for C3 plants and maize, clearly indicating a mixed C3-C4 ecosystem. Principal component analysis and cluster analysis of the FAME concentrations and δ13C values permit to define the compositional associations and group the archaeological samples. Most archaeological samples are close to the pre-industrial composition of llama fat. They were mostly cooking pots where meat and/or grease were stewed with C3 (beans and American algarrobo) and C4 (maize) vegetables. Further evidence for such mixtures provides the microscopic identification of Zea mays, Phaseolus vulgaris and Prosopis sp. starch grains in the organic crust covering the inner wall of several potsherds. For the first time combined microscopic, molecular and isotopic direct evidences indicate that Pre-Columbian societies in the south-central Andes had maize and maize-based food as an important part of their daily foodway.