The road to commercialisation of an unutilised Cyclopia species for herbal tea production – the case of Cyclopia pubescens

Abstract

• C. pubescens was shown to be suitable for production of honeybush herbal tea. • Its sensory profile is similar to that of commercially-cultivated C. subternata . • Other quality parameters were similar to that of C. subternata and C. genistoides . • High-temperature oxidation reduces the xanthone content more than 70%. Cyclopia pubescens is an unutilised species that could potentially be used for production of honeybush tea, if general quality criteria for the herbal tea product could be met. This species is at risk of extinction in the wild, but if suitable for production of honeybush herbal tea, its cultivation could be stimulated. Cyclopia pubescens shoots were used to produce conventional (oxidised) honeybush tea and its quality parameters for the infusion were compared with those of the commercially-cultivated Cyclopia species, C. subternata and C. genistoides . Oxidised C. pubescens had a similar sensory profile to that of C. subternata, displaying ‘woody’, ‘fynbos-floral’ ‘fynbos-sweet’ and ‘sweet spice’ aromas and a slightly sweet taste. The soluble solids concentration, colour and turbidity of the infusions, prepared from the herbal teas of the three species, were similar. The high-temperature oxidation process, essential for the development of the sought-after sensory profile of honeybush tea, reduced the phenolic concentration of the C. pubescens infusions, in particular, the concentration of mangiferin and isomangiferin decreased > 70%. Despite this reduction, C. pubescens infusions would contribute ≥ 8 mg/L to the dietary intake of each of these xanthones. Cyclopia pubescens , thus, passed the first hurdle for commercial herbal tea production, but cultivation would be required as wild-harvesting of this species is not an option.