In the central plain of China, grinding tools are a common category of artefacts at sites attributed to the Peiligang Culture (c. 9000-7000 BP). This paper focuses on the grinding tool assemblage from the site of Tanghu, the largest Peiligang Culture settlement yet discovered. The results from the microwear and residue analyses both suggest that cereals were the primary plant material processed with the grinding tools. Other plants, including acorns and underground storage organs, were also processed, but probably to a smaller extent. Furthermore, microwear analysis suggests that the dry-grinding technique was adopted for cereal processing, and a piece of hideor animal skin was placed underneath the grinding slabs to gather the processed plant material. Apart from plant food processing, one of the grinding tools was also involved in processing bone. These data put more insights into the Neolithic culinary practices and different uses of grinding tools in this region.

China is a major centre for rice domestication, where starch grain analysis has been widely applied to archaeological grinding tools to gain information about plant use by ancient Chinese societies. However, few rice starch grains have been identified to date. To understand this apparent scarcity of starch grains from rice, dry‐ and wet‐grinding experiments with stone tools were carried out on four types of cereals: rice (Oryza sativa L.), foxtail millet (Setaria italica), Job's tears (Coix lacryma‐jobi L.) and barley (Hordeum vulgare L.). The results reveal that dry‐grinding produces significant damage to starches to the point where they may be undetected in archaeological samples, while wet‐grinding causes only slight morphological changes to the starch grains. Moreover, rice starch grains have the most substantial alterations from dry‐grinding, possibly impeding their identification. These findings provide a possible means to explain the relative scarcity of rice starch grains recovered from archaeological grinding tools, which it is suggested was caused by the use of the dry‐grinding technique. Therefore, it is suggested that rice starch grains have been likely underrepresented in the archaeological record, and previous interpretations of starch analyses need to be reconsidered.

The site of Qujialing experienced a long, sustained process of the development of Neolithic culture in the Jianghan Plain, with a period of some1600 years. Our previous studies based on macrofossil remains and phytoliths revealed that rice (Oryza sativa) from Qujialing was already domesticated, and millet (Setaria italica and Panicum miliaceum) had also been spread into the site since the Youziling Culture period (5800-5100 BP). Nevertheless, no direct evidence has been provided regarding the daily consumed plant foods, especially plant foods obtained by gathering, throughout the site occupation. This paper thus examines pottery sherds (n=41) associated with culinary practices from Qujialing with starch grain analysis. Apart from starch grains from rice and millet, the results indicate that job’s tears (Coix lacryma-jobi), lotus roots (Nelumbo nucifera), tubers possibly from Chinese yam (Dioscorea panthainca), acorns (Quercus sp.), and beans (Vigna sp. or/and Vicia sp.) were consumed by the ancient Qujialing people, within job’s tears and lotus roots were not discovered before in the macrofossil remains and phytoliths. Combining the starch data and multiple lines of evidence from macrofossil remains and phytoliths, it is suggested that rice was among the most frequently consumed plant foods since the first occupation phase at Qujialing, while acorns could have been gradually replaced by other agricultural products (i.e., rice) and became less important food ingredients, especially when agriculture was more developed in the last occupation phase at Qujialing. These novel findings not only complement our previous research by providing the first line of evidence of paleodiet in the Jianghan Plain from the perspective of starch grain analysis but also delivers a better understanding of the characterized dietary trends and agricultural development in the research region.