The commercial history of Cape herbal teas and the analysis of phenolic compounds in historic teas from a depository of 1933

In an investigation into the historical use of various plant species as herbal teas in South Africa and the commercialization of rooibos (Aspalathus linearis), 37 tea samples from a depository of 1933 were analysed. These samples are known as the Nortier collection and were put in the depository by Benjamin Ginsberg. Nortier and Ginsberg were instrumental in the commercialisation of Rooibos tea. Liquid-chromatography–high resolution mass spectrometry (LC–HRMS) was used with electrospray ionisation (ESI) in negative mode to compare the flavonoids and phenolic acids and identify marker compounds in the samples. The positively identified marker compounds together with multivariate data tools were used to distinguish between the different teas and group similar ones together. The LC–HRMS chromatogram of the 1933 Nortier tea, the tea from which cultivated rooibos emanated, is virtually identical to a commercial cultivated tea from 2016. The selection of teas is an interesting look into the history of herbal tea in South Africa, the species used and the decision-making process of Nortier in developing the industry. The historic “reed tea” (riettee) was identified for the first time as Thesium macrostachyum and other Thesium species and is the same as the tea that is still used in the Wupperthal area as “lidjiestee”.