Rooibos and honeybush phenolics as drivers of product development – impact on a sustainable South African herbal tea industry

The indigenous South African medicinal fynbos plants, Aspalathus linearis (rooibos) and multiple Cyclopia species (honeybush), largely found traction as herbal teas on the domestic and global markets during the last century [1,2]. Investigations into their phenolic composition have brought the focus back to their medicinal properties, driven from the perspective of present day lifestyle diseases [3]. Opportunities arose for nutraceutical product development as aspalathin and mangiferin, the main phenolic compounds of these herbal teas demonstrated potential in ameliorating features of the metabolic syndrome and delaying its development towards serious metabolic diseases. Given the global prevalence of non-communicable lifestyle diseases, exploitation for nutraceutical production will provide the South African herbal tea industry with new vehicles to expand their economic viability. The commercialisation of rooibos and honeybush represents two different scenarios. The rooibos industry is well established and production depends almost exclusively on cultivation of one particular species, while the honeybush industry is still under development and largely dependent on wild harvesting of a number of Cyclopia species. Increasing demand for honeybush as herbal tea has already escalated unsustainable harvesting practices, placing stress on endangered Cyclopia species. The threat of climate change has renewed interest in wild rooibos types with higher drought resistance and non-utilised Cyclopia species. Genotypes superior in target phenolic compounds may lessen the demand for biomass by the nutraceutical market, but could impact negatively on their consumer acceptance as herbal teas. Several of the UN's Sustainable Development Goals [4] deserve consideration by industry and are relevant to contextualise the potential of these herbs as sources of polyphenols for nutraceutical product development.

[1] Joubert E et al. S Afr J Bot 2011; 77: 887 – 907

[2] Joubert E, De Beer D. S Afr J Bot 2011; 77: 869 – 886

[3] Chellan et al. Planta Med 2014; 80: 622 – 629

[4] https://sustainabledevelopment.un.org/? menu = 1300