Extraction of antioxidant compounds from energy crops.

Energy crops offer enormous opportunities for increasing the sustain ability of agriculture and energy production in the United States. Nevertheless, opportunities for sustaining biomass energy production may well hinge on producing energy and extracting high-value products from the same crop. Seven potential energy crops (mimosa, sericea, kudzu, arunzo, switchgrass, velvet bean, and castor) were extracted and assayed for the presence of potentially high-value antioxidant compounds. Of these crops, mimosa and sericea had the highest antioxidant potential and were selected for further study. High-performance liquid chromatography (ultraviolet) and liquid chromatography/mass spectrometry techniques were then utilized to help identify the compounds with high antioxidant potential using extract fractionation, and total phenolics and oxygen radical absorbance capability assays as a guide. These analyses indicate that methanol extracts of mimosa foliage most likely contain quercetin, a flavonol that has been associated with cardio- protection. Future work will concentrate on quantifying the quercetin content of mimosa (likely parts-per-million levels), as well as identifying and quantifying other antioxidants found in energy crops.