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Macroporous adsorbent resin chromatography fractionation of Cyclopia subternata extract for enhanced valorisation
Thesis (MScFoodSc)--Stellenbosch University, 2022.
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| Language: | en_ZA |
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2022
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| _version_ | 1867613915633942528 |
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| access_status_str | Open Access |
| author | Dippenaar, Carla |
| author2 | De Beer, Dalene |
| author_browse | De Beer, Dalene Dippenaar, Carla |
| author_facet | De Beer, Dalene Dippenaar, Carla |
| author_sort | Dippenaar, Carla |
| collection | Thesis |
| description | Thesis (MScFoodSc)--Stellenbosch University, 2022. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/125059 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:43:44.261Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2022 |
| publishDateRange | 2022 |
| publishDateSort | 2022 |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/125059 Macroporous adsorbent resin chromatography fractionation of Cyclopia subternata extract for enhanced valorisation Dippenaar, Carla De Beer, Dalene Joubert, Elizabeth Sigge, G. O. Stellenbosch University. Faculty of Agrisciences. Dept. of Food Science. Cyclopia subternata (honeybush) -- South Africa Phenols Plant polyphenols -- Health aspects Cyclopia -- Genetic aspects Sensory evaluation Flavor Antioxidant activity Honeybush -- Composition -- Health aspects UCTD Thesis (MScFoodSc)--Stellenbosch University, 2022. ENGLISH ABSTRACT: Value-addition opportunities of plants are closely linked to their phenolic composition as is the case for Cyclopia subternata (honeybush). The present study investigated the potential of C. subternata polyphenols as health ingredients and co-pigments to enhance their value-addition potential in the food industry. A macroporous adsorbent resin chromatography protocol was developed to produce fractions enriched in specific phenolic compounds from a hot water extract of green C. subternata. Small-scale static and dynamic adsorption and desorption experiments were conducted to establish optimal experimental conditions (e.g. loading, elution gradient, temperature) before up-scaling of fractionation. The major phenolic compounds present in the fractions were: fraction 1, 3-β-D-glucopyranosyl-4-O-β-D- glucopyranosyliriflophenone and 3-β-D-glucopyranosyliriflophenone; fraction 2, mangiferin, isomangiferin, 3′,5′-di-β-D-glucopyranosyl-3-hydroxyphloretin (HPDG) and vicenin-2; fraction 3, 3′,5′-di-β-D- glucopyranosylphloretin, eriocitrin and scolymoside; fraction 4, hesperidin and p-coumaric acid. The in vitro antioxidant activity of the extract and fractions was determined using the superoxide anion radical (O₂•−) scavenging, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging and oxygen radical absorbance capacity (ORAC) assays. Their hypouricemic activity was assessed using an in vitro xanthine oxidase (XO) inhibition assay. Fractions 1, 2, 3 and 4 showed the highest ORAC, DPPH• scavenging, O₂•− scavenging and XO inhibitory activities, respectively. For the DPPH• scavenging, ORAC and XO inhibition assays, the most active enriched fractions were more active than the extract. The extract and fractions exhibited relatively poor XO inhibitory activity. The extract and fractions were also investigated as potential co-pigments for stabilisation of the red colour of anthocyanins. An anthocyanin-enriched fraction (AEF), produced from a Pinotage wine with 5.5% of Cabernet Sauvignon using solid-phase extraction, served as a source of anthocyanins. The major monomeric anthocyanins present in AEF were oenin, myrtillin, petunin and peonin. Fraction 2 produced the most pronounced co-pigmentation effect when added to AEF in a model wine solution (pH 3.4, 12% EtOH) at a co-pigment/anthocyanin ratio of 15:1. Co-pigmentation effects were more pronounced at higher co- pigment/anthocyanin ratios and in model wine solutions at pH 3.0 and 0% ethanol. Anthocyanin and colour stability of model wine solutions were monitored during a storage trial at 15°C and 25°C for 12 weeks using fraction 2 at two concentrations. The first-order kinetic model best described the degradation of total monomeric anthocyanins, myrtillin and petunin, while degradation of oenin and peonin followed fractional- conversion kinetics, based on first-order kinetics. The subsequent formation of polymeric anthocyanins was best described by zero-order kinetics. Cyclopia subternata polyphenols showing appreciable degradation (first-order kinetics) were HPDG and mangiferin. The degradation and formation rates were dependent on temperature and sample formulation. In general, the addition of fraction 2 to the AEF model solution resulted in a darker colour, increased saturation and a more red-orange hue compared to the red-blue hue of the AEF model solution. The shift in hue could be attributed to the yellow-orange colour of the co-pigment solutions and the formation of polymeric anthocyanins. The addition of fraction 2 to the AEF model solution improved colour stability with samples stored at 15°C having better colour retention. AFRIKAANSE OPSOMMING: Die waardetoevoegingsgeleenthede van plante word geassosieer met hul fenoliese samestelling, soos ook in die geval van Cyclopia subternata (heuningbos). Die potensiaal van C. subternata polifenole as gesondheidsbestanddele en ko-pigmente is in die huidige studie ondersoek om sodoende hul waardetoevoegingspotensiaal in die voedselindustrie te verbeter. ‘n Makroporeuse adsorberende hars chromatografie protokol is ontwikkel om fraksies wat verryk is in spesifieke fenoliese verbindings te produseer van ‘n warm water ekstrak van groen C. subternata. Kleinskaalse statiese en dinamiese adsorpsie en desorpsie eksperimente is uitgevoer om optimale eksperimentele kondisies (bv. laai, elueer gradient, temperatuur) te bepaal voordat fraksionering opgeskaal is. Die hoof fenoliese verbindings in die fraksies was: fraksie 1, 3-β-D-glukopiranosiel-4-O-β-D- glukopiranosieliriflofenoon en 3-β-D-glukopiranosieliriflofenoon; fraksie 2, mangiferien, isomangiferien, 3′,5′-di-β-D-glukopiranosiel-3-hidroksiefloretien (HPDG) and visenien-2; fraksie 3, 3′,5′-di-β-D- glukopiranosielfloretien, eriositrien en skolimosied; fraksie 4, hesperidien en p-kumariensuur. Die in vitro antioksidant aktiwiteit van die ekstrak en fraksies is bepaal deur gebruik te maak van die superoksied anioonradikaal (O₂•−), 2,2-difeniel-1-pikrielhidrasielradikaal (DPPH•) en suurstofradikaal absorpsie kapasiteit (ORAC) toetse. Hul hipourisemiese aktiwiteit is bepaal deur ‘n in vitro xantienoksidase (XO) inhibisietoets. Fraksies 1, 2, 3 en 4 het onderskeidelik die hoogste aktiwiteit in die ORAC, DPPH•, O₂•− en XO inhibisie toetse getoon. Vir die DPPH•, ORAC en XO inhibisie toetse was die mees aktiewe verrykte fraksies meer aktief as die ekstrak. Die ekstrak en fraksies het relatiewe lae XO inhibisie aktiwiteit getoon. Die ekstrak en fraksies is ook ondersoek as potensiële ko-pigmente vir die stabilisering van die rooi kleur van antosianiene. ‘n Antosianien-verrykte fraksie (AEF), geproduseer van ‘n Pinotage wyn met 5.5% Cabernet Sauvignon deur gebruik te maak van soliede fase ekstraksie, het gedien as antosianienbron. Oenien, myrtillien, petunien en peonien was die hoof monomeriese antosianiene in die AEF. Byvoeging van fraksie 2 tot die AEF in model wynoplossing (pH 3.4, 12% EtOH) in ‘n ko-pigment/antosianien verhouding van 15:1, het die grootste ko-pigmentasie effek veroorsaak. Ko-pigmentasie effekte was groter by hoër ko- pigment/antosianien verhoudings en in model wynoplossings met pH 3.0 en 0% etanol. Antosianien- en kleurstabiliteit van model wynoplossings is gemonitor tydens ‘n opbergingsproef by 15°C en 25°C vir 12 weke deur gebruik te maak van fraksie 2 by twee konsentrasies. Die eerste-orde kinetiese model het die degradasie van totale monomeriese antosianiene, myrtillien en petunien die beste beskryf, terwyl die degradasie van oenien en peonien fraksionele-omskakeling, gebaseer op eerste-orde kinetika, gevolg het. Die gevolglike vorming van polimeriese antosianiene is die beste beskryf deur nul-orde kinetika. Cyclopia subternata polifenole wat merkbare degradasie (eerste-orde kinetika) getoon het was HPDG en mangiferien. Die degradasie- en vormingstempo’s was afhanklik van temperatuur en monster formulasie. In die algemeen het die byvoeging van fraksie 2 tot die AEF modeloplossing gelei tot ‘n donkerder kleur, verhoogde versadiging en ‘n meer rooi-oranje tint in vergelyking met die rooi-blou tint van die AEF modeloplossing. Die verskuiwing in tint kan toegeskryf word aan die geel-oranje kleur van die ko-pigment oplossings en die vorming van polimeriese antosianiene. Die byvoegining van fraksie 2 tot die AEF modeloplossing het die kleurstabiliteit verbeter en monsters wat by 15°C gestoor is, het beter kleurbehoud getoon. Masters 2022-02-23T14:46:41Z 2022-04-29T12:52:12Z 2023-05-03T03:00:10Z 2022-03 Thesis http://hdl.handle.net/10019.1/125059 en_ZA xix, 174 pages : illustrations (some color) application/pdf |
| spellingShingle | Cyclopia subternata (honeybush) -- South Africa Phenols Plant polyphenols -- Health aspects Cyclopia -- Genetic aspects Sensory evaluation Flavor Antioxidant activity Honeybush -- Composition -- Health aspects UCTD Dippenaar, Carla Macroporous adsorbent resin chromatography fractionation of Cyclopia subternata extract for enhanced valorisation |
| title | Macroporous adsorbent resin chromatography fractionation of Cyclopia subternata extract for enhanced valorisation |
| title_full | Macroporous adsorbent resin chromatography fractionation of Cyclopia subternata extract for enhanced valorisation |
| title_fullStr | Macroporous adsorbent resin chromatography fractionation of Cyclopia subternata extract for enhanced valorisation |
| title_full_unstemmed | Macroporous adsorbent resin chromatography fractionation of Cyclopia subternata extract for enhanced valorisation |
| title_short | Macroporous adsorbent resin chromatography fractionation of Cyclopia subternata extract for enhanced valorisation |
| title_sort | macroporous adsorbent resin chromatography fractionation of cyclopia subternata extract for enhanced valorisation |
| topic | Cyclopia subternata (honeybush) -- South Africa Phenols Plant polyphenols -- Health aspects Cyclopia -- Genetic aspects Sensory evaluation Flavor Antioxidant activity Honeybush -- Composition -- Health aspects UCTD |
| url | http://hdl.handle.net/10019.1/125059 |
| work_keys_str_mv | AT dippenaarcarla macroporousadsorbentresinchromatographyfractionationofcyclopiasubternataextractforenhancedvalorisation |