The botanical origin, physicochemical properties and antibacterial activity of selected West Coast honeys
| dc.contributor.advisor | Wossler, Theresa Clair | en_ZA |
| dc.contributor.author | Esterhuizen, Nanike | en_ZA |
| dc.contributor.other | Stellenbosch University. Faculty of Science. Dept. of Botany and Zoology. | en_ZA |
| dc.date.accessioned | 2020-02-16T14:15:13Z | |
| dc.date.accessioned | 2020-04-28T15:10:39Z | |
| dc.date.available | 2020-02-16T14:15:13Z | |
| dc.date.available | 2020-04-28T15:10:39Z | |
| dc.date.issued | 2020-04 | |
| dc.description | Thesis (PhD)--Stellenbosch University, 2020. | en_ZA |
| dc.description.abstract | ENGLISH ABSTRACT: Honey is a complex natural product made by honey bees. In recent years consumer preference in the market has shifted towards honeys with distinct characteristics such as unique floral origin (i.e. monoflorals) and potential health benefits. The specific physical and chemical properties that make every honey unique are primarily influenced by the distinct nectar composition of the plants that were visited by the bees. The Cape Floristic Region (CFR) is characterised by high plant species diversity and exceptionally high species endemism. With the close association between botanical origin and honey properties in mind, this study aimed to identify novel honeys produced from fynbos plants along the West Coast of South Africa that could be marketed as an exclusive, niche product to higher tier local and international consumers. The botanical composition of honeys was investigated by generating the first pollen library for the West Coast and using melissopalynology to identify honey floral components and monofloral varieties. Honey bees preferred and utilised similar floral sources across space and time, with differences in botanical origin between years ascribed to differences in floral availability, due to changes in rainfall. Sandbos (Aspalathus spinescens form A) was the most abundant monofloral honey produced. The physicochemical composition of honey also varied over space and time, as well as with honey age. However, the majority of honeys produced along the West Coast were of good quality and complied with local as well as international regulations – fresh and after 12-months in storage. Hydrogen peroxide was responsible for the antibacterial activity of the West Coast honeys, which was confirmed using a phenol equivalence agar well diffusion assay. Almost 70% of honeys were potentially therapeutically useful, although the variation in antibacterial activity of specific monofloral honey varieties was quite high. Unfortunately, the sample sizes of different honey varieties were limited due to the severe drought conditions experienced between 2015 and 2017, making it difficult to give definitive recommendations on honey properties to be used for value-added marketing. Climate change scenarios predict that the West Coast will become warmer and drier in the future and environmental fluctuations such as changes in rainfall and temperature that affect nectar availability will also greatly influence honey production. The beekeeping industry should focus on optimising the honey yield from drought-tolerant plant species such as sandbos, through the identification and preservation of sites where these plants occur, or through cultivation. This approach of botanical, physicochemical and antibacterial characterisation of honeys produced from indigenous flora could be extended over larger areas of the CFR with the help of beekeepers and citizen science initiatives. Research characterising the unique honeys produced from indigenous vegetation must continue, increasing honey’s value on local as well as international honey markets and in turn boosting the beekeeping industry of South Africa. | en_ZA |
| dc.description.abstract | AFRIKAANSE OPSOMMING: Heuning is 'n komplekse natuurlike produk wat deur heuningbye vervaardig word. In die laaste jare het verbruikersvoorkeur in die mark verskuif na heuning met spesifieke eienskappe, soos unieke plantoorsprong (d.w.s. monoflorale heuning) en potensiële gesondheidsvoordele. Die spesifieke fisiese en chemiese eienskappe wat elke heuning uniek maak, word hoofsaaklik bepaal deur die nektarsamestelling van die plante wat deur bye besoek word. Die Kaapse Floristiese Streek (KFR) word gekenmerk deur 'n groot verskeidenheid plantspesies en baie hoë spesie-endemisme. Met die noue verband tussen heuning-eienskappe en botaniese oorsprong in gedagte, was die doel van hierdie studie om nuwe heuningsoorte, afkomstig van fynbosplante langs die Weskus van Suid-Afrika, te identifiseer wat as 'n eksklusiewe nisproduk aan plaaslike en internasionale verbruikers bemark kan word. Die botaniese samestelling van heuning is ondersoek deur die eerste stuifmeelbiblioteek vir die Weskus saam te stel en melissopalinologie te gebruik om heuning-blomkomponente en monoflorale variëteite te identifiseer. Heuningbye verkies en benut soortgelyke blombronne in ruimte en tyd en verskille in botaniese oorsprong tussen jare word toegeskryf aan verskille in blombeskikbaarheid weens wisselende reënval. Sandbos (Aspalathus spinescens vorm A) was die volopste monoflorale heuning wat geproduseer is. Die fisies-chemiese samestelling van heuning het ook met ruimte en tyd gewissel, asook met heuningouderdom. Die meerderheid heunings was egter van goeie gehalte en het aan plaaslike sowel as internasionale standaarde voldoen – vars en na 12 maande stoortyd. Waterstofperoksied was verantwoordelik vir die antibakteriese aktiwiteit van die heunings, wat bevestig is met behulp van 'n fenol-ekwivalensie agar-diffusietoets. Byna 70% van die heuning was potensieel terapeuties bruikbaar, hoewel die variasie in antibakteriese aktiwiteit van spesifieke monoflorale heuningvariëteite redelik groot was. Ongelukkig was die monstergroottes van verskillende heuningvariëteite beperk vanweë die ernstige droogtetoestande wat tussen 2015 en 2017 ervaar is, wat dit moeilik gemaak het om definitiewe aanbevelings te maak oor heuningeienskappe wat vir waardetoevoegingsbemarking gebruik kan word. Scenario's vir klimaatsverandering voorspel dat die Weskus in die toekoms warmer en droër sal word. Fluktuasies in die omgewing, soos veranderinge in reënval wat die beskikbaarheid van nektar beïnvloed sal ook heuningproduksie beïnvloed. Die byebedryf moet fokus op die optimering van heuningopbrengs van droogtebestande plantspesies soos sandbos, deur die identifisering en bewaring van areas waar hierdie plante voorkom, of deur aanplanting. Hierdie benadering van botaniese, fisies-chemiese en antibakteriese karakterisering van heuning, kan toegepas word oor groter dele van die KFR met behulp van inisiatiewe vir burgerwetenskap. Navorsing wat unieke heunings karakteriseer wat vanaf inheemse plantegroei geproduseer word, moet voortduur om die waarde van heuning op plaaslike sowel as internasionale heuningmarkte te verhoog en sodoende byeboerdery in Suid-Afrika te bevorder. | af_ZA |
| dc.description.version | Doctoral | en_ZA |
| dc.embargo.terms | 2021-02-28 | |
| dc.format.extent | xv, 111 pages : illustrations, maps | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/10019.1/108352 | |
| dc.language.iso | en_ZA | en_ZA |
| dc.publisher | Stellenbosch : Stellenbosch University | en_ZA |
| dc.rights.holder | Stellenbosch University | en_ZA |
| dc.subject | Honey -- Health aspects | en_ZA |
| dc.subject | Botanical origin | en_ZA |
| dc.subject | Physicochemical properties | en_ZA |
| dc.subject | Antibacterial activity | en_ZA |
| dc.subject | Cape Floristic Region | en_ZA |
| dc.subject | Bee culture -- South Africa -- West Coast | en_ZA |
| dc.subject | Beekeeping industry -- South Africa | en_ZA |
| dc.subject | Honey -- Composition | en_ZA |
| dc.title | The botanical origin, physicochemical properties and antibacterial activity of selected West Coast honeys | en_ZA |
| dc.type | Thesis | en_ZA |