Changes in starch grain morphologies from cooking

One of the three main plant microfossils, starch grains are increasingly used as markers of diet, plant domestication, tool use and site organization, because their morphology and features provide a means to identify the plant that produced them. However, starch grains are susceptible to damage when they are exposed to heat in the presence of water, as in cooking. We documented the changes that occur in the starch grains of 10 domesticated plant species due to exposure to different cooking methods, in order to better understand how cooking alters the appearance of the grains, and if these cooking methods might be identifiable in the archaeological record. Our results show that some cooking methods produce unique, identifiable damage on some types of plant starches, but generally each plant species reacts uniquely to cooking. In order to record the changes for each plant species, we have created a database, available at (http://www.osresearch.net/∼hollyf/starchdb/index.cgi), to which registered users can add their own images of cooked starch grains.