How does Rooibos influence stress?
Rooibos is widely used as a herbal tea for enhancing well-being, supporting the immune system and combating stress. During stress, which is characterised by anxiety, sleeplessness and depression, there is an increased production of stress hormones. This project will look at the influence of Rooibos on the biosynthesis of cortisol, since the inhibition of cortisol biosynthesis may alleviate stress symptoms, thus validating the anti-stress potential of Rooibos.

  • Research leader: Prof Amanda Swart, Stellenbosch University
  • E-mail:

How are the quality and sensory parameters of Rooibos measured?
This project aims to characterise a typical cup of Rooibos according to its total polyphenol content and antioxidant capacity. The research team is analysing hundreds of Rooibos tea samples from different regions and seasons, from 2009 to 2011. This research is complemented by a project aimed at a comprehensive description of the taste, flavour and aroma of Rooibos, and the development of a “flavour and mouth-feel wheel” to support the local and international Rooibos trade. THRIP (Technology and Human Resources for Industry Programme) is a co-funder. Professor Joubert collaborates on several other research projects on the health properties of Rooibos in South Africa and abroad.

  • Research leader: Prof Lizette Joubert, Agricultural Research Council
  • E-mail:

How can Rooibos help to protect against exercise-induced damage?
Antioxidants play a vital role in protecting tissues from excessive oxidative damage during exercise. With this project, Professor Marnewick and her team want to determine whether the antioxidants in Rooibos, already found to protect the body against other conditions linked to oxidative stress, can also help to protect against exercise-induced oxidative stress, including biochemical damage and inflammatory responses in cells. They will look at the effect of Rooibos on sport performance in a group of volunteers who will take part in several acute exercise regimes.

  • Research leader: Prof Jeanine Marnewick, Cape Peninsula University of Technology
  • E-mail: