Sensory profile of rooibos originating from the Western and Northern Cape governed by production year and development of rooibos aroma wheel

Jolley, B.; Rijst, Marieta van der; Joubert, Elizabeth; Müller, M.

doi:10.1016/j.sajb.2016.08.005

Cited by 19 publications

(25 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…aroma attributes usually present in high intensities) but not consistently present in all production samples. Similarly, ‘caramel’ was also identified as forming part of the secondary aroma profile of rooibos …”

Section: Resultsmentioning

confidence: 99%

“…‘planky/pencil shavings’, ‘caramel/vanilla’, ‘raisin’, ‘apricot’ and ‘fruity‐sweet’, were used to discriminate between samples. The other aroma attributes are typical of the aroma profile of commercial rooibos . ‘Planky/pencil shavings’, an aroma note not foreign to barrel fermented wines, originates from nonanal .…”

Section: Resultsmentioning

confidence: 99%

“…In total, 12 female assessors were selected according to availability and previous experience in sensory analysis of rooibos . Panel training was conducted in accordance with the consensus method .…”

Section: Methodsmentioning

confidence: 99%

“…The characteristic primary aroma attributes of commercial rooibos infusions (i.e. aroma notes present in all production batches at prominent intensities) include ‘honey’, ‘rooibos‐woody’ and ‘fynbos‐floral’, whereas the taste is slightly sweet and the mouthfeel slightly astringent . The ‘hay/dried grass’ aroma note is also prevalent at low intensities in commercial rooibos infusions and could therefore be considered to be part of the ‘characteristic’ aroma profile of rooibos …”

Section: Introductionmentioning

confidence: 99%

“…aroma notes present in all production batches at prominent intensities) include 'honey', 'rooibos-woody' and 'fynbos-floral', whereas the taste is slightly sweet and the mouthfeel slightly astringent. 4,5 The 'hay/dried grass' aroma note is also prevalent at low intensities in commercial rooibos infusions and could therefore be considered to be part of the 'characteristic' aroma profile of rooibos. 5 Another factor of importance for rooibos is its phenolic content, primarily driven by consumer awareness of the role of rooibos polyphenols in health promotion.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Rooibos agro‐processing waste as herbal tea products: optimisation of soluble solids extraction from dust and application to improve sensory profile, colour and flavonoid content of stem infusions

et al. 2019

View full text Add to dashboard Cite

BACKGROUND Rooibos represents 10% of the global herbal tea market. Shrinking production areas as a result of climate change necessitate the maximum conversion of plant biomass to product. The present study aimed to determine the potential of rooibos tea processing waste (i.e. fine dust and coarse stems) as potential flavour and herbal tea ingredients, respectively. RESULTS Hot water extraction of soluble solids (SS) from rooibos dust was optimised and extracts from different production batches (n = 20) were prepared. Their sensory profiles were similar, although less intense than that of infusions of commercial rooibos (n = 20) when diluted to the same SS content. The turbidity and flavonoid content of the diluted extracts was mostly lower (P < 0.05) than that of commercial rooibos. An atypical and negative aroma attribute, ‘planky/pencil shavings’, was predominant in the stem infusions (n = 20), which contained less SS (P < 0.05) than commercial rooibos. Blends of stem infusion and extract could not effectively mask this negative aroma note (P > 0.05). CONCLUSION Rooibos dust could be used to produce a rooibos flavour extract, whereas the prominent atypical, negative ‘planky/pencil shavings’ aroma note of the stems would limit their inclusion in commercial rooibos blends. © 2019 Society of Chemical Industry

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Rooibos agro‐processing waste as herbal tea products: optimisation of soluble solids extraction from dust and application to improve sensory profile, colour and flavonoid content of stem infusions

et al. 2019

View full text Add to dashboard Cite

show abstract

Development of sensory tools for green rooibos (Aspalathus linearis (Burm.f.) R.Dahlgren) and changes in quality attributes during shelf‐life storage

de Beer,

Human,

du Preez

et al. 2024

J Sci Food Agric

View full text Add to dashboard Cite

BACKGROUNDGreen rooibos (Aspalathus linearis (Burm.f.) R.Dahlgren) herbal tea is popular due to its health‐promoting properties. Information on its characteristic sensory profile is scarce and sensory tools to define product variation are needed. The storage conditions and time during its shelf‐life are hypothesized to affect the product quality.RESULTSProduction batches from two producers spanning 5 years (n = 57) were analyzed using descriptive sensory analysis. Primary attributes (>30 median intensity; 100% occurrence frequency) included ‘hay/dried grass’, ‘cooked oats’, ‘tobacco’, ‘honey’ and ‘caramel’ aromas, and astringent mouthfeel. ‘Cooked vegetables’, ‘green grass’, ‘stewed fruit’, ‘rooibos‐woody’, ‘marmalade’ and ‘cardboard’ aromas, sweet taste and bitter taste were secondary attributes (10–20 median intensity; 100% occurrence frequency). The same flavor attributes were present, except for sweet‐associated and fruity notes. A sensory lexicon and sensory wheels for aroma and palate attributes were constructed from the data. The shelf‐life stability of green rooibos was evaluated in moisture‐impermeable (pouches) and moisture‐permeable (sachets) packaging at 25 and 40 °C at 60% relative humidity over 24 weeks. Green rooibos samples stored in pouches at 4 °C were also evaluated. Storage in sachets led to moisture uptake (~10 g (100 g)−1 dry basis) and an increase in water activity (>0.6), causing degradation of chlorophyll and dihydrochalcones. Changes in color and sensory profile (decreased vegetal, cereal and cardboard aromas and increased sweet‐associated and fruity aromas) were evident and more pronounced at the higher storage temperature.CONCLUSIONSStorage at ≤25 °C in moisture‐impermeable packaging material is recommended for green rooibos herbal tea. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

show abstract

Metabolomic profiling of wild rooibos (Aspalathus linearis) ecotypes and their antioxidant-derived phytopharmaceutical potential

Wilkinson,

Brooks,

Stander

et al. 2024

Metabolomics

View full text Add to dashboard Cite

Introduction Aspalathus linearis (commonly known as rooibos) is endemic to the Cape Floristic Region of South Africa and is a popular herbal drink and skin phytotherapeutic ingredient, with health benefits derived primarily from its unique phenolic content. Several, seemingly habitat-specific ecotypes from the Cederberg (Western Cape) and Northern Cape have morphological, ecological, genetic and biochemical differences. Objectives and methods Despite the commercial popularity of the cultivated variety, the uncultivated ecotypes are largely understudied. To address gaps in knowledge about the biochemical constituency, ultra-performance liquid chromatography-mass spectrometry analysis of fifteen populations was performed, enabling high-throughput metabolomic fingerprinting of 50% (v/v) methanolic extracts. Antioxidant screening of selected populations was performed via three assays and antimicrobial activity on two microbial species was assessed. The metabolomic results were corroborated with total phenolic and flavonoid screening of the extracts. Results and discussion Site-specific chemical lineages of rooibos ecotypes were confirmed via multivariate data analyses. Important features identified via PLS-DA disclosed higher relative abundances of certain tentative metabolites (e.g., rutin, aspalathin and apiin) present in the Dobbelaarskop, Blomfontein, Welbedacht and Eselbank sites, in comparison to other locations. Several unknown novel metabolites (e.g., m/z 155.0369, 231.0513, 443.1197, 695.2883) are responsible for metabolomic separation of the populations, four of which showed higher amounts of key metabolites and were thus selected for bioactivity analysis. The Welbedacht and Eselbank site 2 populations consistently displayed higher antioxidant activities, with 2,2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activities of 679.894 ± 3.427 µmol Trolox/g dry matter and 635.066 ± 5.140 µmol Trolox/g dry matter, respectively, in correlation with a high number of phenolic and flavonoid compounds. The contribution of the individual metabolites to the pharmacological effectiveness of rooibos remains unknown and as such, further structural elucidation and phytopharmacological testing is thus urgently needed.

show abstract

Sensory profile of rooibos originating from the Western and Northern Cape governed by production year and development of rooibos aroma wheel

Cited by 19 publications

References 8 publications

Rooibos agro‐processing waste as herbal tea products: optimisation of soluble solids extraction from dust and application to improve sensory profile, colour and flavonoid content of stem infusions

Rooibos agro‐processing waste as herbal tea products: optimisation of soluble solids extraction from dust and application to improve sensory profile, colour and flavonoid content of stem infusions

Development of sensory tools for green rooibos (Aspalathus linearis (Burm.f.) R.Dahlgren) and changes in quality attributes during shelf‐life storage

Metabolomic profiling of wild rooibos (Aspalathus linearis) ecotypes and their antioxidant-derived phytopharmaceutical potential

Contact Info

Product

Resources

About