Visualization of Aspalathin in Rooibos (Aspalathus linearis) Plant and Herbal Tea Extracts Using Thin-Layer Chromatography
Emily Amor Stander,
Wesley Williams,
Fanie Rautenbach,
Marilize Le Roes-Hill,
Yamkela Mgwatyu,
Jeanine Marnewick,
Uljana Hesse
Affiliations
Emily Amor Stander
South African National Bioinformatics Institute (SANBI), University of the Western Cape, Robert Sobukwe Road, Bellville 7535, South Africa
Wesley Williams
South African National Bioinformatics Institute (SANBI), University of the Western Cape, Robert Sobukwe Road, Bellville 7535, South Africa
Fanie Rautenbach
Oxidative Stress Research Centre, Faculty of Health and Wellness Sciences, Institute of Biomedical and Microbial Biotechnology, Cape Peninsula University of Technology, Symphony Road, Bellville 7535, South Africa
Marilize Le Roes-Hill
Biocatalysis and Technical Biology Research Group, Institute of Biomedical and Microbial Biotechnology, Cape Peninsula University of Technology, Symphony Road, Bellville 7535, South Africa
Yamkela Mgwatyu
South African National Bioinformatics Institute (SANBI), University of the Western Cape, Robert Sobukwe Road, Bellville 7535, South Africa
Jeanine Marnewick
Oxidative Stress Research Centre, Faculty of Health and Wellness Sciences, Institute of Biomedical and Microbial Biotechnology, Cape Peninsula University of Technology, Symphony Road, Bellville 7535, South Africa
Uljana Hesse
South African National Bioinformatics Institute (SANBI), University of the Western Cape, Robert Sobukwe Road, Bellville 7535, South Africa
Aspalathin, the main polyphenol of rooibos (Aspalathus linearis), is associated with diverse health promoting properties of the tea. During fermentation, aspalathin is oxidized and concentrations are significantly reduced. Standardized methods for quality control of rooibos products do not investigate aspalathin, since current techniques of aspalathin detection require expensive equipment and expertise. Here, we describe a simple and fast thin-layer chromatography (TLC) method that can reproducibly visualize aspalathin in rooibos herbal tea and plant extracts at a limit of detection (LOD) equal to 178.7 ng and a limit of quantification (LOQ) equal to 541.6 ng. Aspalathin is a rare compound, so far only found in A. linearis and its (rare) sister species A. pendula. Therefore, aspalathin could serve as a marker compound for authentication and quality control of rooibos products, and the described TLC method represents a cost-effective approach for high-throughput screening of plant and herbal tea extracts.
