The following objectives will be met:
<ol><LI>To identify harvesting techniques that optimize the active principle (AP) content of feverfew (Tanacetum parthenium), St. John's wort (Hypericum perforatum), purple coneflower (Echinacea purpurea) and other echinacea species (E. pallida and E. angustifolia). Marker compounds that are used as indicators of AP in these plants, respectively,are parthenolide, hypericin, chicoric acid and echinacosides.
<LI>To identify postharvest curing (drying conditions) that optimize AP, focusing on elapsed time from harvest until curing initiation, curing temperature, time, and relative humidity.
<LI>To determine if nitrosamines are formed in medicinal plant tissues during the curing process when gas combustion is used as the heat source.
<LI>To evaluate the influence of the physical state of AP,e.g. dried whole fiber, powdered plant material, or extracted AP in solution or suspension, on its stability in storage. To determine the influence of storage conditions on stability of AP with emphasis on time, temperature,relative humidity, and packaging interactions.
<LI> To identify food groups and specific food characteristics that are suited to the use of medicinal plant AP as a dietary supplement, e.g. functional food development.
<LI>To develop and improve upon analytical techniques for the extraction and analysis of medicinal plant AP, using high performance liquid chromatography as the primary analytical tool.
<LI>To report the results of all studies in appropriate scientific literature in a timely manner.</ol>
The medicinal plant species listed above will be cultivated at the Coastal Research and Education Center. Harvest will be conducted either by hand or mechanically with modified mowers or choppers. Curing will be conducted in either a static system or with a forced-air curing chamber equipped with programmable temperature and relative humidity controls. In some tests, to analyze possible nitrosamine formation in plant tissues, a gas-fired curing chamber will be utilized. Dried plant tissues, powdered plant material, and extracted AP in solution or suspension will be stored in controlled- environment chambers.
In functional food studies, extracted AP will be added to specific food types, e.g. alkaline, acidic or pH neutral, and food groups, e.g.protein-based, lipid-based, or carbohydrate-based, and its stability/compatibility with each food type tested.
In all studies, medicinal plant AP will be extracted utilizing current industry techniques and analyzed with high performance liquid chromatography.</p>