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Villaño D, Pecorari M, Testa MF, Raguzzini A, Stalmach A, Crozier A, Tubili C, Serafini M. Unfermented and fermented rooibos teas (Aspalathus linearis) increase plasma total antioxidant capacity in healthy humans. Food Chem 2010. [DOI: 10.1016/j.foodchem.2010.05.032] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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152
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Joubert E, Viljoen M, De Beer D, Malherbe CJ, Brand DJ, Manley M. Use of green rooibos (Aspalathus linearis) extract and water-soluble nanomicelles of green rooibos extract encapsulated with ascorbic acid for enhanced aspalathin content in ready-to-drink iced teas. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:10965-10971. [PMID: 20923193 DOI: 10.1021/jf103552f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Heat-induced changes in aspalathin, iso-orientin, and orientin content of ready-to-drink (RTD) green rooibos iced tea formulations were investigated. An organic-solvent-based aspalathin-enriched extract prepared from green rooibos was used "as-is" or encapsulated with ascorbic acid in a water-soluble nanomicelle-based carrier system. The common iced tea ingredients, ascorbic acid, and/or citric acid were added to the iced tea containing green rooibos extract. Only citric acid was added to the iced tea containing the nanomicelles. Heat treatments consisted of pasteurization (93 °C/5 min and 93 °C/30 min), normal-temperature sterilization (NTS; 121 °C/15 min), and high-temperature sterilization (HTS; 135 °C/4 min). Pasteurization had little or no effect on the flavonoid content. NTS and HTS induced significant losses in the flavonoids. The addition of citric and ascorbic acids improved the stability of the flavonoids, but encapsulation of green rooibos extract with ascorbic acid in nanomicelles did not offer additional stability. The only benefit of using the water-soluble nanomicelles was the improved clarity of the RTD product. Iso-orientin and orientin contents were substantially less affected than aspalathin by the heat treatments, partially because of conversion of aspalathin to these flavones, which countered losses. 5-Hydroxymethylfurfural (HMF), a known dehydration product of hexoses under mild acidic conditions and also a degradation product of ascorbic acid, was observed in formulations containing citric and/or ascorbic acids.
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Affiliation(s)
- Elizabeth Joubert
- Agricultural Research Council (ARC) Infruitec-Nietvoorbij, Private Bag X5026, Stellenbosch 7599, South Africa
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153
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Arthur H, Cameron M, Joubert E, Witthuhn RC. Identification of bacterial species on Lippia multiflora herbal tea leaves and the influence of steam pasteurization. World J Microbiol Biotechnol 2010. [DOI: 10.1007/s11274-010-0450-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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154
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de Beer D, Joubert E. Development of HPLC method for Cyclopia subternata phenolic compound analysis and application to other Cyclopia spp. J Food Compost Anal 2010. [DOI: 10.1016/j.jfca.2009.10.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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155
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Chuarienthong P, Lourith N, Leelapornpisid P. Clinical efficacy comparison of anti-wrinkle cosmetics containing herbal flavonoids. Int J Cosmet Sci 2010; 32:99-106. [DOI: 10.1111/j.1468-2494.2010.00522.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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156
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157
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Sprent JI, Odee DW, Dakora FD. African legumes: a vital but under-utilized resource. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:1257-65. [PMID: 19939887 DOI: 10.1093/jxb/erp342] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Although nodulated legumes have been used by indigenous peoples in Africa for centuries, their full potential has never been realized. With modern technology there is scope for rapid improvement of both plant and microbial germplasm. This review gives examples of some recent developments in the form of case studies; these range from multipurpose human food crops, such as cowpea (Vigna unguiculata (L.) Walp.), through to beverages (teas) that are also income-generating such as rooibos (Aspalathus linearis (Burm. f.) R. Dahlgren, honeybush (Cyclopia Vent. spp.), and the widely used food additive gum arabic (Acacia senegal (L.) Willd.). These and other potential crops are well-adapted to the many different soil and climatic conditions of Africa, in particular, drought and low nutrients. All can nodulate and fix nitrogen, with varying degrees of effectiveness and using a range of bacterial symbionts. The further development of these and other species is essential, not only for African use, but also to retain the agricultural diversity that is essential for a changing world that is being increasingly dominated by a few crops such as soybean.
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Affiliation(s)
- Janet I Sprent
- Division of Plant Sciences, College of Life Sciences, University of Dundee at SCRI, Invergowrie, Dundee DD2 5DA, UK.
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158
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Sinisalo M, Enkovaara AL, Kivistö KT. Possible hepatotoxic effect of rooibos tea: a case report. Eur J Clin Pharmacol 2010; 66:427-8. [DOI: 10.1007/s00228-009-0776-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Accepted: 12/08/2009] [Indexed: 11/24/2022]
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159
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Joubert E, Manley M, Maicu C, de Beer D. Effect of pre-drying treatments and storage on color and phenolic composition of green honeybush (Cyclopia subternata) herbal tea. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:338-344. [PMID: 19916502 DOI: 10.1021/jf902754b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The effect of various pre-drying treatments and storage temperatures on the color (L*, a*, b*, chroma, and hue angle) and phenolic composition of green Cyclopia subternata was investigated. Pre-drying treatments, which included comminution+drying (T2), steaming (ca. 90-93 degrees C/60 s)+comminution + drying (T3), and comminution+steaming+drying (T4), had a detrimental effect (p<0.05) on the color parameters relative to the control (T1) (drying of intact leaves). All drying took place at 40 degrees C and 30% relative humidity (RH). Of the pre-drying treatments (T2, T3, and T4), the best retention of the green leaf color was observed for T3 (p<0.05). T2 reduced the SS and TP contents of the leaves (p<0.05) as well as the content of individual phenolic compounds, including mangiferin, isomangiferin, and eriocitrin. Scolymoside did not follow the same trend as the other compounds, with the intact leaves having the lowest content. It is postulated that oxidation of eriocitrin (eriodictyol-7-O-rutinoside) to scolymoside (luteolin-7-O-rutinoside) occurred with comminution and steaming. The phenolic composition of samples, subjected to T1 and T3 and a 6 month storage period at 0 and 30 degrees C, remained stable. Storage at 30 degrees C resulted in detrimental color changes, leading to the loss of the green leaf color irrespective of the pre-drying treatment.
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Affiliation(s)
- Elizabeth Joubert
- Agricultural Research Council (ARC) Infruitec-Nietvoorbij, Private Bag X5026, Stellenbosch 7599, South Africa.
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160
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Reichelt KV, Peter R, Paetz S, Roloff M, Ley JP, Krammer GE, Engel KH. Characterization of flavor modulating effects in complex mixtures via high temperature liquid chromatography. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:458-464. [PMID: 19924859 DOI: 10.1021/jf9027552] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The identification of flavor modulating compounds, for example, bitter masking or sweet enhancing compounds, in complex mixtures such as botanical extracts or food preparations is difficult and time- and work-intensive. To accelerate this process, an improved screening method was developed on the basis of the separation of complex matrixes by the so-called LC Taste setup and subsequent comparative sensory analysis. The eluent containing only water and ethanol was diluted with a basic tastant solution (500 mg L(-1) caffeine and 5% sucrose, respectively) and evaluated by a trained panel by duo comparison tests. This novel method was applied to the known flavor and taste modulating substances homoeriodictyol (1), sterubin (2), hesperetin (3), and lactisol (9) as well as to simple mixtures of homoeriodictyol (1), sterubin (2), and hesperetin (3). To evaluate the potential of the method for more complex matrixes, the protocol was applied to plant extracts from Yerba Santa (Eriodictyon californicum) and honeybush tea (Cyclopia intermedia). The flavor modulating activities reported for homoeriodictyol (1), sterubin (2), and hesperetin (3) could be confirmed in these complex mixtures.
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Affiliation(s)
- Katharina V Reichelt
- General Food Technology, Center of Life and Food Sciences, Technische Universität München, Freising-Weihenstephan, Germany
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161
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Snijman PW, Joubert E, Ferreira D, Li XC, Ding Y, Green IR, Gelderblom WCA. Antioxidant activity of the dihydrochalcones Aspalathin and Nothofagin and their corresponding flavones in relation to other Rooibos ( Aspalathus linearis ) Flavonoids, Epigallocatechin Gallate, and Trolox. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2009; 57:6678-6684. [PMID: 19722573 DOI: 10.1021/jf901417k] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The antioxidant activity of rooibos flavonoids, including the dihydrochalcones aspalathin and nothofagin and their corresponding flavone glycosides, was evaluated using the ABTS radical cation, metal chelating, and Fe(II)-induced microsomal lipid peroxidation assays. Epigallocatechin gallate (EGCG) and Trolox were used as reference standards. Optimized geometric conformers of aspalathin and nothofagin, in addition to calculated physicochemical properties, were considered to explain interaction with the microsomal membrane structure and thus relative potency of the dihydrochalcones. The most potent radical scavengers were aspalathin (IC50 = 3.33 microM) and EGCG (IC50 = 3.46 microM), followed by quercetin (IC50 = 3.60 microM) and nothofagin (IC50 = 4.04 microM). The least effective radical scavengers were isovitexin (IC50 = 1224 microM) and vitexin (IC50 > 2131 microM). Quercetin (IC50 = 17.5 microM) and EGCG (IC50 = 22.3 microM) were the most effective inhibitors of lipid peroxidation. Aspalathin (IC50 = 50.2 microM) and catechin (IC50 = 53.3 microM) displayed similar potencies. Nothofagin (IC50 = 1388 microM) was almost as ineffective as its flavone glycoside analogues.
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Affiliation(s)
- Petra W Snijman
- Departments of Chemistry, Stellenbosch University, Private Bag X1, Matieland (Stellenbosch) 7602, South Africa
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162
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Joubert E, Viljoen M, De Beer D, Manley M. Effect of heat on aspalathin, iso-orientin, and orientin contents and color of fermented rooibos (Aspalathus linearis) iced tea. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2009; 57:4204-4211. [PMID: 21314198 DOI: 10.1021/jf9005033] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The phenolic quality of commercial South African fermented rooibos iced teas in terms of aspalathin, iso-orientin, and orientin contents in comparison to a "cup of tea" was shown to be inferior. The role of the different manufacturing stages of powdered extract used in iced tea formulation and, more specifically, the impact of pasteurization and sterilization on the color and phenolic content of the beverage, were assessed as potential causes of its inferior phenolic quality. Aspalathin and its corresponding flavones, iso-orientin and orientin, were found to be present at all stages of the powdered extract production process. Spray-drying did not significantly (P ≥ 0.05) alter the aspalathin, iso-orientin, or orientin content of concentrates. Simulated normal-temperature sterilization (NTS at 121 °C/15 min) and high-temperature sterilization (HTS at 135 °C/4 min), but not necessarily pasteurization (93 °C/30 min), significantly (P < 0.05) reduced the aspalathin, iso-orientin, and orientin contents of different iced tea formulations. Heat-induced losses of iso-orientin and orientin were lower than those for aspalathin. Conversion of aspalathin to the flavones is implicated. The addition of ascorbic acid and/or citric acid to the base iced tea formulation containing only rooibos extract and sugar proved to be beneficial, especially for the retention of aspalathin. Browning, that is, absorbance at 420 nm, was significantly (P < 0.05) increased in the base formulation. In the case of the formulations also containing ascorbic acid and/or citric acid, absorbance remained unchanged or decreased when subjected to NTS and HTS treatments. This was attributed to removal of brown polymers from solution as the pH values of these formulations were lower than that of the base formulation.
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Affiliation(s)
- Elizabeth Joubert
- ARC Infruitec-Nietvoorbij, Private Bag X5026, Stellenbosch 7599, South Africa.
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163
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de Beer D, Jerz G, Joubert E, Wray V, Winterhalter P. Isolation of isomangiferin from honeybush (Cyclopia subternata) using high-speed counter-current chromatography and high-performance liquid chromatography. J Chromatogr A 2009; 1216:4282-9. [DOI: 10.1016/j.chroma.2009.02.056] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Revised: 01/27/2009] [Accepted: 02/19/2009] [Indexed: 11/25/2022]
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164
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Abstract
South African herbal teas, rooibos and honeybush, are increasingly enjoyed as healthy alternatives to Camellia sinensis teas. They contribute to the diet with bioactive phytochemicals not commonly found in foods. Major compounds of rooibos are the unique dihydrochalcone, aspalathin, and its flavone isomers, orientin and isoorientin. Honeybush contributes the xanthones, mangiferin and isomangiferin and the flavanones, eriocitrin, narirutin and hesperidin. All these compounds are either C-glucosides or O-rhamnoglucosides, which are poorly absorbed. Phase II metabolism and degradation by intestinal bacteria are important factors in their absorption. Modulation of drug metabolising enzymes is indicated which not only could affect the therapeutic window of drugs, but also the bioavailability of other dietary flavonoids.
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165
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