Earliest known well-preserved flour comestibles unearthed in the Wupu Cemetery in Hami, Xinjiang, China

Exploring the utilisation of flour in ancient Xinjiang is crucial for understanding the use of different grain crops as staple comestibles. In this study, multiple analyses were applied to identify five flour food remnants discovered in the Wupu Cemetery (1100–400 BCE) in Hami, Xinjiang. Results show that two of the samples were comprised of broomcorn millet (Panicum miliaceum) mixed with wheat (Triticum aestivum) and barley (Hordeum spp.), one of wheat and barley, and the remaining two primarily of broomcorn millet with a low quantity of foxtail millet (Setaria italica). Plant microfossils analysis and microscopic observation of cross-sections of the five samples indicate that these crop materials were coarsely ground into flour and then probably baked without fermentation. These findings provide the earliest evidence that broomcorn millet, wheat, and barley were processed as cakes in Hami 3000 years ago. Moreover, the findings in this study also emphasise the reassessment of the role of foxtail millet in the dietary consumption of the ancient Wupu inhabitants, as foxtail millet was abundant in tombs, but scarce in comestible food sources. This research sheds light on and contributes to a more precise reconstruction of the dietary patterns of ancient indigenous people in Hami.