Thesis (MScAgric (Agronomy)--Stellenbosch University, 2008. / Honeybush (Cyclopia spp. Fabaceae) is indigenous to the fynbos botanical biome of the Eastern and Western Cape of South Africa. The increase in the international demand for honeybush tea for health benefits, concern over exploitation of wild populations and the lack of published agronomic information necessitated this study to evaluate different aspects of honeybush propagation. The main objectives of this study were to evaluate the effect of species and cutting position on rooting of cuttings of Cyclopia species using different rooting hormones, to evaluate the effect of an organic plant fertilizer and cutting position on growth and establishment of rooted cuttings and to study the influence of different seed pre-treatments on germination of Cyclopia species. Terminal and sub-terminal cuttings of C. intermedia and C. genistoides treated with different rooting hormones were rooted under day/night temperature controlled glasshouse conditions. Intermittent mist was used as means of moisture supply to the cuttings for 45-60 seconds daily every 30 minutes. C. genistoides rooted significantly better compared to C. intermedia as measured by rooting percentage, number of roots per cutting, length of longest root and mean root length during the summer season. The cutting position had a significant effect on rooting of the cuttings in summer compared to winter and spring season. The interactive effect of species, treatment and cutting position resulted into 86% of rooting in summer from the terminal cuttings of C. genistoides, while only 4% was recorded as the highest rooting percentage in both winter and spring seasons. The highest number of roots and the greatest root length per cutting were obtained with 2 and 4 g L-1 IBA from terminal cuttings of C. genistoides and these hormone concentrations were not significantly different to each other. To evaluate the effect of an organic plant fertilizer and cutting position on plant growth and establishment, rooted cuttings of two Cyclopia species (C. intermedia and C. genistoides) from two cutting positions (terminal and sub-terminal) were transferred to pots (576 cm3) and treated with Nitrosol fertilizer at application rates of 3.33 ml.L-1, 1.67 ml.L-1 and 0 ml.L-1 (control). Cyclopia plantlets were uniformly inoculated once with a symbiotic Rhizobium bacteria to improve the formation of nodules. Nitrosol® at 3.33 ml.L-1 significantly affected fresh and dry plant weight, fresh and dry root weight, number of shoots and nodules per plant compared to either 1.67 ml.L-1 or the control. Relative to species, C. genistoides performed better in terms of fresh and dry plant weight, fresh and dry root weight, and number of shoots and nodules per plant compared to C. intermedia. The origin of the cutting position did not significantly affect the above mentioned parameters. Plant mineral analysis revealed that most of the essential elements increased with increasing Nitrosol® application rates, with C. genistoides having higher levels of mineral elements than C. intermedia. This could be an indication of the differences between the two species in terms of nutrient uptake, utilization and distribution within the plant tissues. In the germination studies, seeds obtained from different seed sources of Cyclopia species were subjected to different pre-sowing treatments. Seed treatments were sulphuric acid (95%), hot water (100°C), water with smoke paper disk, and demineralised water (control). The study revealed that all the treatments had a significant effect on germination with the exception of eight year old seeds obtained from C. subternata (seed source two). Although hot water treatment improved germination compared to smoked paper disk and the control, seeds treated with hot water degenerated rapidly. The highest overall germination (77.33%) was found with one year old seeds compared to other seed sources older than one year. Although smoked paper disks generally did not improve germination compared to the control, in one year old seeds from seed source one, this treatment greatly influenced germination, suggesting that seed age might have influenced germination of these seeds. In terms of germination rate, germination generally started after four days in most treatments.

Thesis (MSc Food Sc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Application of steam treatment to green Cyclopia maculata and C. longifolia to modulate their aroma and flavour profile, without detrimental effects on colour and individual phenolic content, was investigated. Steam treatment (96 °C, atmospheric pressure) of different time periods was applied to the shredded, fresh plant material before drying (STBD; 0, 30, 60, 90 and 120 s) or the herbal tea product after drying (STAD; 0, 1, 2, 3, and 4 min). Steam treatment of 60 s or longer resulted in a significant (p < 0.05) decrease in vegetative (‘green grass’ and ‘hay/dried grass’) and cereal (‘oats/porridge/grains’) aroma and flavour intensities, with an increase in some fruity (‘tropical fruit’ and ‘guava’) and ‘fruity-sweet' aroma intensities. These changes manifested to a greater degree for plant material subjected to STBD, while they were less prominent for C. longifolia compared to C. maculata. Additionally, 19 aroma compounds were instrumentally identified in the volatile fraction of C. maculata infusions prepared from STBD plant material. Of these, seven correlated well with green honeybush vegetative and cereal aroma attributes associated with unsteamed samples. Steaming thus resulted in the rapid loss of some of these highly volatile ‘green’-associated aroma compounds. Steam treatment of more than 60 s, regardless of STBD or STAD, was not detrimental to green colour, and individual phenolic content was not greatly affected. The 30 s STBD treatment of C. maculata, however, led to the rapid loss of green colour and oxidation of phenolic compounds, without considerable aroma improvement. This highlights the need for process control during green honeybush production. Storage stability of steamed (60 s, STBD) and unsteamed green C. maculata was investigated under low (0 °C; moisture impermeable packaging) and normal (25 °C at 60% relative humidity (RH); semi-moisture-permeable sachets) temperature storage conditions (LTS and NTS, respectively) over 6 months and high temperature storage (HTS) conditions (40 °C at 75% RH; semimoisture- permeable sachets) for 1 month. HTS conditions, after 1 month, seemed to emulate changes occurring over 6 months at NTS conditions, with little change detected at LTS conditions. Despite noticeable green colour loss over the respective storage periods at NTS and HTS conditions, individual phenolic compounds were not severely affected. NTS and HTS led to the progressive development of sought-after fermented honeybush sensory attributes, especially in unsteamed samples. These include prominent fruity (‘stewed fruit’, ‘apricot jam’ and ‘marmalade’) aromas and flavours, ‘general sweet’ and ‘fruity-sweet’ aromas and a sweeter taste. The collated descriptive sensory data were used to generate a preliminary sensory wheel for green honeybush aroma, and another for flavour, taste and mouthfeel. The sensory profile of green honeybush was finally described as a dominant vegetative aroma and flavour, prominent sweetassociated and slightly fruity aroma, with sweet and notably bitter tastes and an astringent mouthfeel. By combining the sensory data, it was clear that the major effects of storage outweighed those of steam treatments, suggesting that storage of 3 to 6 months may improve sensory quality, although colour may be slightly compromised. Immediate sensory manipulation and thus improvement, however, may be achieved to a lesser degree in the short term by STBD. / AFRIKAANSE OPSOMMING: Die toepassing van stoombehandeling van groen Cyclopia maculata en C. longifolia vir die modulasie van hul aroma en geur profiel, sonder gepaardgaande nadelige gevolge op kleur en individuele fenoliese inhoud, is ondersoek. Stoombehandeling (96 °C, atmosferiese druk) van verskeie tydstippe is toegepas op die gekerfde, vars plantmateriaal voor droging (SBVD; 0, 30, 60, 90 en 120 s) of die groen teeproduk ná droging (SBND; 0, 1, 2, 3 en 4 min). Stoombehandeling van 60 s of langer het tot 'n betekenisvolle (p < 0.05) afname in vegetatiewe (‘groen gras’ en ‘hooi/gedroogde gras’) en graan (‘hawer/pap/graan’) aroma en geur intensiteite gelei, met 'n toename in sommige vrugtige (‘tropiese vrugte’ en ‘koejawel’) en ‘vrugtige-soet’ aroma intensiteite. Hierdie veranderinge was meer merkbaar in die SBVD behandeling, terwyl C. longifolia minder vatbaar vir hierdie veranderinge was as C. maculata. Daarbenewens is 19 aromaverbindings in die vlugtige fraksie van C. maculata aftreksel voorberei van SBVD plantmateriaal instrumenteel geïdentifiseer. Sewe hiervan het goed gekorreleer met heuningbos vegetatiewe en graan aromas wat verband hou met ongestoomde monsters. Stoombehandeling het dus gelei tot die vinnige verlies van sommige van hierdie baie vlugtige ‘groen’-geassosieërde aromaverbindings. Stoombehandeling vir langer as 60 s, ongeag van SBVD of SBND, het nie die groen kleur en individuele fenoliese inhoud grootliks nadelig beïnvloed nie. ‘n SBVD behandeling van 30 s het egter tot die vinnige verlies van groen kleur en oksidasie van fenoliese verbindings, sonder aansienlike aroma verbetering van C. maculata gelei. Dít beklemtoon die noodsaaklikheid vir prosesbeheer tydens groen heuningbosproduksie. Stabiliteit van gestoomde (60 s, SBVD) en ongestoomde groen C. maculata tydens opberging onder lae (0 °C; vog-ondeurlaatbare verpakking) en normale (25 °C by 60% relatiewe humiditeit (RH); semi-vogdeurlaatbare sakkies) temperatuur opbergingtoestande (LTO en NTO, onderskeidelik) oor 6 maande en hoë temperatuur opbergingtoestande (40 °C by 75% RH; semivogdeurlaatbare sakkies; HTO) vir 1 maand, is ondersoek. HTO het na 1 maand soortgelyke veranderinge teweeggebring as NTO na 6 maande, terwyl min verandering by LTO bespeur is. Ten spyte van merkbare groen kleur verlies oor die onderskeie tydperke by NTO en HTO is individuele fenoliese verbindings min beinvloed. NTO en HTO het gelei tot die progresiewe ontwikkeling van gesogte sensoriese eienskappe van gefermenteerde heuningbos, veral in ongestoomde monsters. Dit sluit in prominente vrugtige (‘gestoofde vrugte’, ‘appelkooskonfyt’ en ‘marmelade’) aromas en geure , ‘algemene soet’ en ‘vrugtige-soet’ aromas en 'n soeter smaak. Al die beskrywende sensoriese data is saamgestel om 'n voorlopige sensoriese wiel vir groen heuningbos aroma op te stel, asook een vir geur, smaak en mondgevoel. Die sensoriese profiel van groen heuningbos kan beskryf word as 'n oorheersende vegetatiewe aroma en geur, prominente soet-verwante en effens vrugtige aroma, met soet en veral bitter smaak en ‘n vrank mondgevoel. Deur die sensoriese data te kombineer kon duidelik uitgewys word dat die belangrikste gevolge van opberging dié van stoombehandeling oortref. Dit dui daarop dat opberging van 3 tot 6 maande sensoriese kwaliteit kan verbeter, hoewel kleur effens benadeel kan word. In die kort termyn kan onmiddellike sensoriese manipulasie en dus verbetering egter in 'n mindere mate deur SBVD bereik word.