Enhancing fruity and sweet-associated aroma attributes of honeybush tea (Cyclopia spp.) by ultra-high temperature oxidation

Abstract

Ultra-high temperature oxidation (UHTO) was explored as an alternative to the standard oxidation of honeybush tea, aiming to shorten the processing time and enhance the fruity and sweet-associated sensory characteristics. Different UHTO temperature × time regimes were applied to Cyclopia subternata, C. genistoides, C. intermedia and C. longifolia. Descriptive sensory analysis showed that UHTO treatment, regardless of species, increased the intensities of fruity and sweet-associated aromas while decreasing the intensities of floral aromas. The optimal UHTO regime for each species was subsequently applied to a larger number of plant material batches (n = 10 per species) to introduce a wider range of intra-species variation and confirm broad trends for the sensory profile, as well as for the colour and phenolic composition, of the infusions over species. The effect of treatment conditions on the retention of the phenolic compounds varied, depending on the compound and species. The substantial decrease in the mangiferin and isomangiferin concentrations of C. genistoides infusions, which was not observed for the other species, was notable. The study highlights the potential of UHTO to reduce oxidation time while enhancing the fruity and sweet-associated aroma attributes of honeybush tea, changes that may be beneficial in attracting new consumers and expanding the honeybush tea market.

Keywords

• Cyclopia
• Descriptive sensory analysis
• Herbal tea
• Honeybush
• Colour
• Phenolic compounds