Proximate composition of prairie turnip Pediomelum esculentum of the He Sapa (Black Hills) and Great Plains of Western South Dakota

Abstract: Breadroot scurfpea (Pediomelum esculentum) is also known by various names such as Timpsila, Indian Breadroot, Indian Turnip, or Prairie Turnip. This indigenous plant is commonly found in the Great Plains. Timpsila produces a spindle tuber below the surface of the ground, which has historically been used as nutritional resource by Native Americans in the Great Plains. Besides being nutritionally enriched, Timpsila is believed to have several medicinal benefits. However, there are no scientific reports that documents the compositional and nutritional profile of Timpsila. Additionally, some reports indicate the morphological variations in the Timpsila based on the plant age and geographical locations. Therefore, the goal of the study is to determine the proximate composition of Timpsila harvested from different locations in the Black Hills and Great Plains of the Western South Dakota.

Method: It is very critical that plant is identified correctly in its natural environment, hence Timpsila was located, marked, and harvested from the different geographical locations. Whole plant (leaves, stems, roots, tubers, flowers, seeds) and soil samples were collected from the seven different locations. All plants were of different ages and size. While moisture, ash content and crude fibers were determined for leaves and stems, and the soil samples were evaluated to isolate the microbial communities. The tuber (edible part) of the plant was processed, dried, ground and subjected to various analysis including crude protein, crude fiber, starch content, amino acids, total phenolic content, phytic acid, etc. The results showed that tubers are low moisture (~5.5%) containing products with the crude protein content ranging from 5.3-7.2%. All other results are currently pending analysis. This study is of highly significance as it provides the complete nutritional and proximate composition of the Timpsila.