Rooibos

Bramati, L. et al.. Quantitative characterization of flavonoid compounds in Rooibos tea (Aspa-lathus linearis) by LC-UV/DAD, J. Agric. Food Chem., 50, 5513, 2002. 

Schulz, H., Joubert, E., and Schutze, W., Quantification of quality parameters for reliable evaluation of green rooibos Aspalathus linearis), Eur. Food Res. Technol, 216, 539, 2003. 

Marais, C. et al., (S)- and (R)-eriodictyol-6-C-p-D-glucopyranoside, novel keys to the fermentation of rooibos Aspalathus linearis). Phytochemistry, 55, 43, 2000. 

The dihydrochalcones aspalathin and nothofagin have been identified as the main flavonoids in the South-African Rooibos tea (Aspalathus linearis) [41]. 

Figure 1.17 Hydroxychalcones occurring in unfermented rooibos tea and flavanone...

Joubert E, Ferreira D. 1996. Antioxidants of rooibos tea—a possible explanation for its health promoting properties SA J Food Sci Nutr 8 79-83. 

Krafczyk N, Glomb MA. 2008. Characterization of phenolic compounds in rooibos tea. J Agric Food Chem 56 3368-3376. 

McKay DL, Blumberg JB. 2007. A review of the bioactivity of South African herbal teas Rooibos (Aspalathus linearis) and honeybush (Cyclopia intermedia). Phy-totherap Res 21 1-16. 

Gilani AH, Khan AU, Ghayur MN, Ali SF, Herzig JW. 2006. Antispasmodic effects of Rooibos tea (Aspalathus linearis) is mediated predominantly through K + -channel activation. Basic Clin Pharmacol Toxicol 99 365-373. 

In the food industry, these natural products have now been classified under a new class of food called nutraceuticals or functional foods, because these products provide a health benefit beyond basic nutrition 22, 23). According to Wilkinson 24), most of the nutraceuticals used in the food industry are plant derived. Further, Addae-Mensah (25), showed that the world trade in medicinal plants accounts for about 30% of the total dmg market and was estimated excluding plants used as raw material sources for the essential oils required to manufacture cosmetics, food additives and other non-medicinal purposes. The increased recogiution of the value of natural products in the pharmaceutical, neutraceutical, cosmetic and other industries have created a huge demand for raw natural products. By taking Rooibos tea as an example from South Africa, Wilson 26) in detail describes the demand for Rooibos from different countries. However, for many natural products estimation of the actual demand is very difficult and the data sparse given the diversity of natural products used across industries and production variation within and across countries and the lack of... 

Rooibos and Honeybush Recent Advances in Chemistry, Biological Activity and Pharmacognosy... 

Both rooibos and honeybush speoies belong to the Fynbos biome, which accounts for more than 80% of the plant speoies in the Cape Floral Kingdom, the smallest but highest in biodiversity of the six plant kingdoms in the world. 

Antioxidant content/capacity Traditional S rooibos Green rooibos Traditionaf honeybush Green honeybush... 

The aroma volatiles of honeybush have also been reported by Wang et al (27). The aroma components were dominated by monoterpene alcohols, of which a-terpineol (28%) was the major component, with minor amounts of linalool (7%), nerol (2%) and geraniol (8%). These monoterpenes are responsible for the sweet, floral and fruity notes of the tea, while other components such as phenylethyl alcohol (3%) and 5-methylfurfural (2.1%) imparted also sweet and honey notes. Other volatiles such as eugenol (6%), linalool oxides (7%), and methyl-heptenol (3%) were also detected. With both honeybush and rooibos, the exact nature of the aromas and flavor will depend significantly on the species collected, time of collection, drying, fermentation and processing (27). 

Rooibos and honeybush also contain essential micro- and macro elements, with the traditional/fermented forms containing lower amoimts of elements than the green Vimfermented forms (28). The levels of Al and Ni in the rooibos and... 

Table II. Mineral Content of Traditional/Fennented and Green Rooibos...

NOTE aRf-raw/inf fermented rooibos plant material/infusion bRg-raw/inf green rooibos plant material/infusion cHf-raw/inf fermented honeybush plant material/infusion dHg-raw/inf green honeybush plant material/infusion. e 0.0 less than 0.1 All plant materials were bought in a market in Czech Republic. 

Japanese and South African researchers were the first to scientifically investigate the possible health promoting properties of rooibos which led to publications reporting on various biological activities (31-37). A few studies regarding the in vitro, in vivo and ex vivo biological activities of honeybush has been published by mainly South African researchers and are mostly limited to the exported species, Cyclopia intermedia. These studies will be discussed. 

---