Analysis of nutritional components in edible parts of eastern redbud (Cercis canadensis L.)
Laura J. Hunter, Michael C. Pilkington, Vanessa M. Andrews, Shelena M. Thomas, Rebekah D. Molina, and Nancy L. Paiva. Southeastern Oklahoma State University, Durant, OK
Redbud trees are native across much of the continental U.S., with Cercis canadensis L. being the most common species. Redbuds are small leguminous trees which are among the first to bloom in the spring and also produce large numbers of multi-seeded pods in late summer. In the early 1900's, Native Americans were reported to consume redbud flowers raw or boiled, and consume seeds after roasting in the seedpods, but little phytochemical analysis has been published. In addition to providing vitamins and other essential trace nutrients at a time of year when few vegetables are available, the pigments in the pink/red flowers might also have nutritional value. Preliminary characterization of acidic methanol flower extracts using HPLC, LC-MS and other techniques revealed a high content of anthocyanins, which are known to be beneficial antioxidants in humans. Green developing seeds exhibited intense red staining of the outer layers in the presence of a vanillin/HCl reagent, but no red staining in HCl alone, indicating high concentrations of condensed tannins (proanthocyanidins), another class of beneficial antioxidants in humans. GC-MS analysis of FAME derivatives of chloroform/methanol lipid extracts from two ages of green seeds revealed the presence of the essential fatty acids linoleic and alpha-linolenic acid, although alpha-linolenic acid was absent from mature dried seeds. Oleic and palmitic acids were also abundant. Amino acid analysis is underway, to determine the quality of the seed protein. The edible redbud plant parts clearly offered highly beneficial nutrients to early inhabitants of North America.