Topic: chemical compositions and mineral content of four selected South African herbal teas and the synergistic response of combined teas

Abstract

PurposeThe present study was carried out to determine (1) essential minerals, total polyphenols, total flavonoids, moisture and ash of four selected South African herbal teas and (2) the effect of blending bush tea with other known commercial herbal teas.Design/methodology/approachThe method used to determine moisture and ash contents followed that of the Association of Official Analytical Chemists (AOAC). Nine minerals were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES). The total phenolic and flavonoid contents were determined by Folin–Ciocalteu assay and aluminum chloride colorimetric assay, respectively.FindingsThe results of the study demonstrated that bush tea had a high ash content of 8.01% and special tea (9.23%), while honeybush (1.96%) and rooibos tea (2.17%) exhibited a low ash percentage. The mineral content was higher in bush tea and special tea than in rooibos tea and honeybush tea except for sodium, which was higher in rooibos tea. The blending of bush tea with special tea improved its potassium content from 22,937.00 mg/kg to 23,379.20 mg/kg. Blending bush tea with rooibos tea at a ratio of 25:75 increased the flavonoid content to 12.21 µg/mL.Research limitations/implicationsThe results of the nutrients composition cannot be generalized as it is influenced by other factors such as soil type and seasons.Social implicationsIncreasing the commercialization of indigenous teas.Originality/valueThe results of the study suggest that bush tea and special tea are nutritionally comparable with South African commercial herbal teas. Thus, the consideration for commercialization of these teas is crucial.

Non-Volatile and Volatile Bioactives of Salvia officinalis L., Thymus serpyllum L. and Laurus nobilis L. Extracts with Potential Use in the Development of Functional Beverages

“…Our findings were not supported by Studzińska-Sroka et al [ 49 ], whose results of TPC in herbal tea blends correlated with a high content of flavonoids in the mixture of mulberry leaves and cinnamon bark (70:30) (2.23 mg QE g −1 herbal blend). The results were also different in research by Malongane et al [ 48 ], where bush tea alone contained the lowest flavonoid content, but the flavonoid content increased in two-component mixtures.…”

“…However, the highest TPC was determined in the WTS31 mixture (2.51 g L −1 ). Malongane et al [ 48 ] also reported TPC in two-component herbal teas. They studied the TPC of honeybush ( Cyclopia species ), rooibos ( Aspalathus linearis (Burm.f.)…”

Anti-Inflammatory, Anti-Diabetic, Anti-Oxidant and Cytotoxicity Assays of South African Herbal Teas and Bush Tea Blends

“…The IC 50 of honeybush tea (54.98 µg/mL) was higher than that of bush tea (20.82 µg/mL), showing the lowest anti-oxidant activity, while special tea and its blends with bush tea (BS50:50 and BS25:75) showed high anti-oxidant activity, exhibiting IC 50 values of 2.74 µg/mL, 1.33 µg/mL and 0.62 µg/mL, respectively. The higher anti-oxidant activity of special tea may be due to a higher total phenolic and flavonoid content, as indicated in the preliminary study of the current research [ 38 ]. The same study reported that honeybush has the lowest total phenolic content, thus confirming the lower anti-oxidant activity exhibited by honeybush tea in this study.…”