Analyses for Flavonoid Aglycones in Fresh and Preserved

Abstract

In the past, perennial and temperate-zone tree-form Hibiscus species and hybrids have been relegated to the status of little-known garden plants, at least in the United States. However, their potential as a new source of edible flowers and natural food colorants (all within the anthocyanin class of edible flower pigments) elevates them to the status as—possibly the newest—of the New Crops. The 17 indigenous native Hibiscus species of North America range from USDA Zones 4–10 and, in the wild, are confined to wetland areas. In cultivation, the plants are installed in permanent plantations, using zero-runoff protocols under passive flooding, or drip irrigation protocols. Other hardy perennial and treeform species from Asia, including H. mutabilis, H. syriacus, and the Pan-Pacific species H. hamabo and H. tileaceous are suitable for USDA Zones 8–10. Potential products from these cultivars include fresh food (primarily edible flowers for the restaurant trade) and natural food colorants, as well as edible seed meals and seed proteins (for nutraceutical applications), seed oils, lubricants, and fiber, mucilages and complex polysaccharides from fruiting organs, roots, canes, and/or branches. In this paper, the flowers of selected native North American, non-native Asiatic and pan-Pacific species and North American hybrid cultivars were selected for preliminary analysis of pigments. The 29 species and hybrid Malvaceae utilized for the chemical characterizations of the pigments in the fresh flowers are listed in Table 1. These include Hibiscus species native to the continental US: Hibiscus aculeatus (light yellow with small red eye); H. coccineus (solid orange/red); H. laevis (cream to blush with red eye); H. martianus (solid red); H. moscheutos (white to cream or blush with red eye); H. striatus lambertianus (light purple with small light-red eye); and several hybrids of three of these native species [including BOSTx®HHHybrids: ‘Governor Ann’ (mulitple types); ‘Nathan’s Star’; ‘Pink Hybrids’ (mixed types); ‘Purple Hybrids’; ‘Razberri Rhapsody’; and ‘Razberri Ruffles’] (Fig. 1). Representative photos of BOSTx®HHHybrids cultivars are available for viewing at BOSTx.com. In addition, some non-Hibiscus genera of Malvaceae that are native to the US were also analyzed, including Kosteletzkya virginica (pink with yellow eye), Malvaviscus arboreus drummondii (solid orange), Pavonia lasiopetalus (solid pink), and Sida spinosa (solid yellow). Non-native Malvaceae used in the analyses included Abelmoschus moschatus (two forms, orange and red, tropical Asia), H. calyphyllus (yellow, Madagscar), H. mutabilis (peach, China), H. paramutabilis (red, China), H. rosa-sinensis (orange, pan-Pacific), H. syriacus (blue, China), and M. arboreus mexicana (orange, Central Americas). Our methods and the results of the analyses are detailed below.

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Cite this paper

@inproceedings{Flowers2002AnalysesFF, title={Analyses for Flavonoid Aglycones in Fresh and Preserved}, author={Hibiscus Flowers and Lorraine S. Puckhaber and Robert D Stipanovic and Georgia A. Bost}, year={2002} }