Thesis (M.Tech.: Food Technology)-Dept of Biotechnology, Durban University of Technology, 2007 xvi, 106 leaves / Alicyclobacillus acidoterrestris is a spore-forming spoilage micro-organism found in fruit juices whose spores are not destroyed by typical pasteurisation. Once its spores outgrow and multiply in finished juice products, they produce two volatile taint compounds namely guaiacol and 2,6-dibromophenol. In the food industry margins for errors are small and monitoring of products to avert such errors is crucial. Conventional microbiological monitoring is one such technique for spoilage micro-organisms another being automated systems which can detect taints. Both these categories were evaluated in this study with the electronic nose and gas chromatograph being the specific automated systems being assessed. Sensory evaluation was also assessed as a diagnostic tool in the detection of taints. Isolation and identification of what was thought to be A. acidoterrestris was a laborious and expensive exercise which eventually proved inconclusive. A pure culture was purchased and juices were then inoculated with two levels of A. acidoterrestris spores and incubated. Juices from each level of inoculation were evaluated at different time intervals via the above-mentioned monitoring techniques. Of the three media assessed in the microbiological method, Bacillus acidoterrestris medium (BAM) was found to be the most effective for enumerating A. acidoterrestris followed by K-medium (KM) then Orange Serum Agar (OSA). While BAM was still indicating the presence of A. acidoterrestris KM and OSA were not (counts of <10cfu/g). This illustrated that this micro-organism could be easily overlooked if KM or OSA were being used to enumerate them. Considering that many workers actually do use KM and OSA as their media of choice in enumerating A. acidoterrestris (perhaps because BAM is very tedious to prepare) the cause for concern is a real one. Assessment of the resultant taints via sensory evaluation after inoculation and incubation reveals the inability of many panellists to detect taints at levels (as assessed by GC) far above their documented threshold values. While GC is an extremely useful and powerful tool, the level of expertise and skill required to use such an instrument cannot be overlooked nor can the expense involved. With regard to the electronic nose assessment for the presence of the volatile taint compounds, an important finding was that the electronic nose indicated significant differences between test and control samples when panellists performing sensory evaluation did not. This also correlated to an interval when enumeration on OSA illustrated no A. acidoterrestris after several days of inoculation and incubation and BAM and KM did. Without implying that the electronic nose has no drawbacks, it has proved, in this instance to be a simple and easy piece of equipment to use. It can be used to detect taints produced under simulated spoilage conditions at reduced analysis times, levels of expertise, cost and energy.

Please read the abstract in the section 00front of this document / Dissertation (MSc (Agric) Horticultural Science)--University of Pretoria, 2005. / Plant Production and Soil Science / unrestricted

M.Sc.(Agric) / Department of Horticultural Sciences

Typescript, etc.

Call number: LD2668 .T4 1946 M6 / Master of Science

Call number: LD2668 .T4 1959 K46

LD2668 .T4 1965 W916 / Master of Science

Call number: LD2668 .T4 1966 N156 / Master of Science

No description available.

Thesis (MComm)—Stellenbosch University, 2015. / ENGLISH ABSTRACT: The second step in the study was to empirically measure the competitive performance of the date industry based on this trade orientation, using the relative trade advantage (RTA) method. Trade data from FAOSTAT and Trademap were used. Since 2001, the Namibian date industry has consistently recorded positive trends with RTA values ranging between 0.40 and 4.0. When compared to other international competitors, the results indicate that Tunisia is by far the most competitive country, with RTA values ranging between 278 and 391. Namibia’s date industry leads competitors such as South Africa, the USA, Kenya, Australia and India. In step 3, an industry-wide survey was conducted among executive-level industry role players, which identified 72 factors influencing competitive performance. The 72 factors were rated and analysed through chi-square and one-way analysis of variance (ANOVA) in terms of their current impact as enhancing or constraining and also in terms of their relevance to the industry. The results revealed that all factors were rated highly relevant (i.e. important) to the industry’s competitive performance levels, with 47 percent playing an enhancing role, while 43 percent were constraining competitive performance in the Namibian date industry. Differences between views on the current impact and long-term relevance of factors provided a ‘performance gap’ that the industry had to attend to strategically in order to improve competitive performance. The top three most enhancing factors are the substantial size of the international date market, the availability of unskilled labour, and the suitability of Namibian date production (project) locations. The highest rated constraining factors were identified as: the lack of privately funded scientific research capacity, the slow growth and small size of local markets, and insufficient industry expenditure on research and development (R&D). The fourth step applied Porter’s theory of competitiveness (1990; 1998) to derive the industry determinants of competitive performance. The 72 factors were grouped into the six Porter diamond determinants. Principal component analysis (PCA) was undertaken to identify variations and consensus in the views of respondents with respect to the relevance and impact of factors identified for each determinant. The results revealed that there were variations in opinions with regard to 52 factors and consensus on 20 factors, influencing the industry’s competitive performance. In analysing opinions on the impacts and long-term relevance of the identified factors, two value chain clusters were identified, viz. those opinions or respondents directly involved in the production processes of dates (cluster 1); and those providing supporting functions to the production process (cluster 2). The results indicate that although there are similarities in the opinions within the date industry value chain, important differences do exist and must be noted in strategic planning process by the industry. Differences were recorded with regard to access to quality technology, obtaining long-term credit, diversification in the international market, cost of specialised technology services, the effect of legal and political factors on the industry’s strategic position, the country’s black economic empowerment (BEE) policy and health cost implications. In step 5, the most important findings from steps 3 and 4, together with views gathered from a date industry information session (the DIS) and personal interviews, were included in a strategic decision matrix aimed to develop industry-level proposals to improve competitive performance. This matrix listed constraining factors for which a large degree of industry-level consensus was recorded, together with those actions that could improve performance immediately. Proposals highlighted were: focusing on human resources and skills development; cost-sharing activities; public-private partnerships in the development of project-level socio-economic investment packages, investing in long-term research and development (R&D); upgrading export facilities; local market development and improved collaboration with national retailers; reduction of marketing costs; export-market diversification; developing representative industry-level institutions and an industry-level strategic plan; and mobilising government-level support more effectively in order to create a conducive environment for the industry to compete successfully. / AFRIKAANSE OPSOMMING: Hierdie studie het die mededingende prestasie van die Namibiese dadelbedryf vanaf 2001 tot 2013 ondersoek. In die studie is die konvensionele raamwerk vir die mededingendheidsanalise van agribesigheid (verwys na Ismea, 1999; Esterhuizen, 2006; Van Rooyen et al., 2011; Boonzaaier, 2014; Jafta, 2014) verfyn om die geldigheid van die vrae wat die respondente geantwoord het en die verskille in hulle response teenoor huidige impakte en langtermyn relevansie te oorweeg. Opinies vanuit die waardeketting van die dadelbedryf is ook ingesluit in die ontledings. Die konsep van mededingendheid is eerstens gedefinieer, gebaseer op die belangrikheid van internasionale handel vir die Namibiese dadelbedryf, as die vermoë van die dadelbedryf om sy produkte op ’n volhoubare basis in beide binnelandse en internasionale markte te verhandel en, as sulks, te kan voortgaan om skaars hulpbronne soos grond, arbeid, tegnologie, bestuurstalente en kapitaal te lok en terselfdertyd ten minste die geleentheidskoste van opbrengste op hulpbronne verbruik, te verdien (aangepas uit die werk van Freebairn, 1986; Esterhuizen, 2006; Van Rooyen et al., 2011). Die tweede stap in die studie was om die mededingende prestasie van die dadelbedryf empiries te meet op grond van hierdie handelsoriëntasie deur gebruik te maak van die relatiewe handelsvoordeel (relative trade advantage (RTA)) metode. Handelsdata afkomstig van FAOSTAT en Trademap is gebruik. Sedert 2001 het die Namibiese dadelbedryf konsekwent positiewe tendense vertoon, met RTA-waardes wat gewissel het tussen 0.40 en 4.0. In vergelyking met ander internasionale mededingers toon die resultate dat Tunisië verreweg die mees mededingende land is, met RTA-waardes van tussen 278 en 391. Namibië se dadelbedryf loop egter voor teen mededingers soos Suid-Afrika, die VSA, Kenia, Australië en Indië. In stap 3 is ’n bedryfswye opname onder bestuursvlak- rolspelers onderneem. Hierin is 72 faktore geïdentifiseer wat mededingende prestasie beïnvloed. Die 72 faktore is geëvalueer en deur middel van chi-kwadraat en eenrigting analise van variansie (ANOVA) geanaliseer in terme van hulle huidige impak as óf versterkend óf stremmend, en ook in terme van hulle relevansie vir die bedryf. Die resultate het getoon dat al die faktore as hoogs relevant (m.a.w. belangrik) vir die bedryf se mededingende prestasievlakke geëvalueer is, met 47% wat ’n versterkende rol gespeel het, terwyl 43% mededingende prestasie in die Namibiese dadelbedryf gestrem het. Verskille tussen die sienings oor die huidige impak en die langtermyn relevansie van die faktore het ’n ‘prestasiegaping’ voorsien wat die bedryf strategies aan aandag moet skenk om die mededingende prestasie te verbeter. Die drie top versterkende faktore was die grootte van die internasionale dadelmark, die beskikbaarheid van ongeskoolde arbeid en die gepastheid van die dadelproduksie (projek)-gebiede. Die stremmende faktore wat die belangrikste geag is, is geïdentifiseer as die gebrek aan privaatbefondsde wetenskaplike navorsing, die baie stadige tempo van groei in plaaslike markte en onvoldoende bedryfsbesteding op navorsing en ontwikkeling (R&D). In die vierde stap is Porter se mededingendheidsteorie (1990; 1998) toegepas om bedryfsdeterminante van mededingende prestasie af te lei. Die faktore vanaf stap 3 is in die ses Porter-diamant determinante gegroepeer. Hoofkomponent-ontleding (principal component analysis (PCA)) is onderneem om verskille en konsensus in die sienings van die respondente met betrekking tot die relevansie en impak van die faktore wat vir elke determinant geïdentifiseer is, te identifiseer. Die resultate het getoon dat daar groot verskille in opinies was met betrekking tot 52 faktore en konsensus oor 20 faktore wat die bedryf se mededingende prestasie beïnvloed. Deur die opinies oor die impakte en langtermyn relevansie van die geïdentifiseerde faktore te analiseer, is twee waardeketting bondels geïdentifiseer, naamlik daardie opinies of respondente wat direk in die produksieprosesse van dadels betrokke is (bondel 1); en dié wat ondersteuningsfunksies verskaf (bondel 2). Die resultate dui aan dat hoewel daar ooreenkomste in opinies binne die waardeketting van die dadelbedryf is, is daar belangrike verskille wat bestaan en aangeteken is. Verskille, waarvan kennis geneem moet word in strategiese bedryfsbeplanning, is aangeteken met betrekking tot toegang tot hoë kwaliteit tegnologie, die verkryging van langtermyn krediet, diversifikasie in die internasionale mark, die koste van gespesialiseerde tegnologiese dienste, die effek van wetlike en politiese faktore op die bedryf se strategiese posisie, die land se beleid van swart ekonomiese bemagtiging (SEB), en gesondheidskoste-implikasies. In stap 5 is die belangrikste bevindings in stappe 3 en 4, tesame met die sienings wat tydens ’n dadelbedryfinligtingsessie bekom is, in ’n strategiese besluitnemingsmatriks ingesluit. Klem is gele op faktore waaroor die bedryf grootliks saamstem. Die doel was om bedryfsvlakvoorstelle te ontwikkel om die mededingende prestasie van die bedryf te verhoog. Hierdie matriks het gefokus op die stremmende faktore waaroor ’n groot mate van bedryfsvlak-konsensus opgeteken is, tesame met daardie aksies wat die prestasie onmiddellik sou kon verbeter. Die voorstelle wat vooruitstaan is: ’n fokus op die ontwikkeling van menslike hulpbronne en vaardighede; koste-delende aktiwiteite; openbare-private vennootskappe in die ontwikkeling van projekvlak sosio-ekonomiese beleggingspakkette, met ’n belegging in langtermyn navorsing en ontwikkeling (R&D); opgradering van uitvoerfasiliteite; plaaslike markontwikkeling en verbeterde samewerking met nasionale handelaars; vermindering van bemarkingskostes; diversifikasie van uitvoermarkte; ontwikkeling van verteenwoordigende bedryfsvlak- instellings en ’n bedryfsvlak- strategiese plan; en die meer doeltreffende mobilisering van regeringsvlak-ondersteuning om ’n omgewing te ontwikkel wat bevorderlik is vir die bedryf om suksesvol te kan kompeteer.