Archaeological laboratory extraction procedures and starch degradation: Effects of sonication, deflocculation, and hydrochloric acid on starch granule morphology

Abstract Archaeobotanists have used techniques including sonication and acid dissolution to recover starch granules from artifacts for over a decade, however there has been little published research on the effects of these extraction procedures on starch granule morphology. Recently published research in the food sciences literature suggests these procedures could modify granule morphology. Deflocculation has generally not been used to recover starch granules from artifacts, and the effects of deflocculant exposure to starches have not been sufficiently studied. This paper presents the results of three experiments assessing the effects of low-intensity sonication, exposure to dilute hydrochloric acid, and exposure to sodium hexametaphosphate deflocculant on the morphology of modern potato (Solanum tuberosum), wheat ( Triticum aestivum ), and maize ( Zea mays ) starch granules. Morphometric analysis indicates that exposure to deflocculant solution may cause subtle changes in the shape of maize starches, but these changes are too slight to affect identification. In all other cases, these laboratory procedures did not cause detectable or consistent changes in the morphology of starch granules between replicate experiments.