Effect of Rooibos preparation on the total polyphenol content and antioxidant capacity of herbal tea and its consumer characteristics

Abstract

Background: The different types and forms of rooibos and the ways in which it is prepared and flavoured for consumption influences its total polyphenol content and total antioxidant capacity (TAC) and hence depends on its consumer practices. Design: Phase 1 of the study entailed the selection and preparation of different rooibos types and forms; rooibos brewed for different times; and with different household and commercially added flavourings to determine the total polyphenol content, TAC, flavonol and flavanol content; and subsequent identification of the optimal cup of rooibos based on the first two biochemical parameters. For Phase 2 a questionnaire was used to obtain information on the profile of the adult rooibos herbal tea consumer, as well as of those consuming the optimal cup of rooibos. Results: The following prepared rooibos samples delivered the higher biochemical parameter content: green / unfermented (type representative); green / unfermented leaves and powdered extract (form representatives); that brewed for 10 minutes or longer; and those with added honey. The optimal cup of rooibos was identified as the one brewed for 10 minutes or longer. The older respondents and those with a lower level of education consumed a higher daily amount of rooibos (p < 0.05) and those who brewed rooibos in a teapot consumed the optimal cup (p < 0.05). However, very few respondents consumed the advised number of cups per day (< 1%) and the identified optimal cup (15.9%). Conclusions: Rooibos consumers in this study did not consume it in sufficient amounts and did not brew it for long enough to fully gain from its attributed health benefits.