Rooibos agro-processing waste as herbal tea products: optimisation of soluble solids extraction from dust and application to improve sensory profile, colour and flavonoid content of stem infusions.

Rooibos dust could be used to produce a rooibos flavour extract, whereas the prominent atypical, negative 'planky/pencil shavings' aroma note of the stems would limit their inclusion in commercial rooibos blends. © 2019 Society of Chemical Industry.