Aurignacian grinding stone from Surein I (Crimea): “trace-ing” the roots of starch-based diet

Morpho-chemical characterization of individual ancient starches retrieved on ground stone tools from Palaeolithic sites in the Pontic steppe

“…The sampled GSTs are stored in museum collections. Archaeological site Site type Tool identifier Synthetic description 4 , 6 , 19 GST attributed function Surein I (Crimea) Rockshelter #NN† Large oval GST, square 9B, lowermost layer III, limestone Grinding stone (passive tool) Brînzeni I (Moldova) Cave # 442 Subrectangular fragment of a large GST, fragment that refits with BZ#NN, square 12 g, lowermost layer III, quartz-arenite Grinding stone (passive tool) Brînzeni I (Moldova) Cave # NN† Fragment of a large GST, (refits with BZ#442), square 11j, lowermost layer III, quartz-arenite Grinding stone (passive tool) Brînzeni I (Moldova) Cave # 833 Large fragment that refits with BZ#2965, square 12 g, lowermost layer III, quartzite Pestle (active tool) Brînzeni I (Moldova) Cave #2965 Small fragment refits with BZ#833, square 12 g, lowermost layer III, quartz-arenite Pestle (active tool) Brînzeni I (Moldova) Cave #3539 Small oval GST, square 16 e, lowermost layer III, greywacke Grinding stone (passive tool) Brînzeni I (Moldova) Cave #6707 Large rectangular GST, lowermost layer III, quartz-arenite Grinding stone (passive tool) Brînzeni I (Moldova) Cave #177 Large broken GST, square 9 i, lowermost layer III, quartz-arenite Grinding stone (passive tool) Kostenki 14, Markina-Gora (Russia) Open air ...…”

“…From here on, the analyzed SU-RBRs will be referred to as Ancient Starch Candidates (ASC), and ranked from ASC1 to ASC4 according to the dislodgement procedures detailed elsewhere 4 , 6 , 19 . The origin of ASCs, a brief description of their isolation procedure and the analytical techniques exploited for their characterization are summarized in Table 2 .…”

“…The origin of ASCs, a brief description of their isolation procedure and the analytical techniques exploited for their characterization are summarized in Table 2 . The same information is reported in Table 2 also for Modern Starch References (MSRs), extracted in water from underground and above storage organs (USOs and ASOs, respectively) of wild plants selected among those potentially available during the study conditions, according to the literary review of the relevant pollen lists 4 , 6 , 19 – 21 and also ethnobotanical sources 22 , with the aim to build a chemometric model for ASCs classification.…”

“… Acronym Origin Dislodgment procedures 4 , 6 , 19 Brief description Characterization techniques used ASC-1 Brînzeni I, Surein I, Kostenki 14 Molding with Provil L (polyvinyl siloxane) creates the peel-off effect of the adhering residues and a copy of the stone surface to detect wear-traces Starch grains were observed only by means of SEM, scanning directly the molds peeled off from the used areas of the GST SEM ASC-2 Brînzeni I The thin encrustations adhering onto the GST used surfaces were powdered and sonicated in ultrapure water The suspensions were deposited on ZnSe windows and analyzed 19 SEM, FTIRI ASC-3 Brînzeni I, Surein I, Kostenki 14 Material aliquots were isolated by direct sonication of part of the molds (by indentation) in ultrapure water The suspensions were deposited on ZnSe or Si windows and analyzed 6 , 19 SEM, FTIRI ASC-4 Brînzeni I, Surein I, Kostenki 14 Selected surfaces of the GST were sonicated in ultrapure water; the suspensions were stabilized with a few drops of EtOH and the solution was processed according to published protocols 23 in two different labs (Paris and Vladivostok). The procedure allows for the extraction of isolated starch grains The suspensions were deposited on a glass slide to be analyzed by OM 6 , 19 . In a second instance, the starches were recovered from the glass slide by suctioning in 50 μL of DI water and dropped onto CaF 2 or ZnSe windows for SEM and IRSR-FTIR analysis 6 , 19 OM, SEM, IRSR-FTIRM MSR Pre-Alps (Northern Italy) Starch grains extracted in water from modern plants available in the Pontic steppe, selected according to literary review The suspensions were deposited on a glass slide to be analyzed by OM and on ZnSe windows for SEM and FTIRM analysis ...…”

“…The procedure allows for the extraction of isolated starch grains The suspensions were deposited on a glass slide to be analyzed by OM 6 , 19 . In a second instance, the starches were recovered from the glass slide by suctioning in 50 μL of DI water and dropped onto CaF 2 or ZnSe windows for SEM and IRSR-FTIR analysis 6 , 19 OM, SEM, IRSR-FTIRM MSR Pre-Alps (Northern Italy) Starch grains extracted in water from modern plants available in the Pontic steppe, selected according to literary review The suspensions were deposited on a glass slide to be analyzed by OM and on ZnSe windows for SEM and FTIRM analysis 6 , 19 OM, SEM, FTIRM Meaning of acronyms: OM, Optical Microscopy; SEM, Scanning Electron Microscopy; FTIRI, Fourier Transform Infrared Imaging; FTIRM, Fourier Transform Infrared Microscopy with conventional IR glow-bar source; IRSR FTIRM, Fourier Transform Infrared microscopy with infrared synchrotron radiation. …”