Thesis (MScAgric)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Citrus fruit exported from South Africa to markets such as the USA and China undergo a mandatory 24 day exposure of -0.6°C during shipment to kill any insect larvae in the fruit, however, this protocol causes chilling injury (CI). The aim of this study was firstly to determine the influence of various preharvest factors on chilling sensitivity. In addition, Near-Infrared (NIR) spectroscopy was tested as a potential management tool to identify variation in CI susceptibility of fruit and lastly the efficacy of thiabendazole (TBZ) applied in the packline to reduce CI was determined. Various factors influence the susceptibility of a navel orange fruit to CI including cultivar, micro-climate, harvest date, fruit size and rind colour. In this study it was found that ‘Washington’ was more susceptible to CI compared to ‘Navelina’ navel orange. Fruit from the coldest part of Citrusdal (Tharakama) had the highest incidence of CI, which concurred with literature. The incidence of CI was overall less when fruit were harvested in the middle of the commercial harvest window; however, the internal maturity at harvest does not appear to be related to the sensitivity of orange fruit to CI. Near infrared (NIR) spectroscopy was tested as a potential tool to predict fruit quality parameters in relation to CI. Analysing the NIR data with principal components analysis (PCA), score plots were obtained that separate fruit in clusters from the inside and outside of the canopy positions as well as different sizes and rind colours (green vs. orange). However, analysing data with partial least square regression (PLS) using fruit quality parameters (firmness, rind colour and mass), the NIR spectra obtained with the integrated sphere did not provide a good prediction model for CI index. Thiabendazole (TBZ) is reported to reduce the incidence of CI of citrus fruit and this fungicide was applied in a semi-commercial packline in the wax as well as the drench. The results of the application of different fungicides from the TBZ chemical group indicated that the TBZ dip treatments had the highest efficacy in reducing both the incidence and severity of CI and in addition were more effective when applied in warm (40°C) than cold water (10°C). Applications at the commercial recommended rate (20mL.L-1 and half of the commercial recommended rate were both effective in reducing the incidence of CI. Wax application was effective in reducing the incidence of CI however, the application of TBZ in the wax reduced the incidence of CI even more. For the successful reduction of CI incidence in commercial shipments of citrus fruit the focus should not be on a single factor but rather a strategy that encompasses pre-harvest factors that would influence rind quality as well as specific postharvest technologies know to decrease the impact of CI. / AFRIKAANSE OPSOMMING: Sitrus vrugte ondergaan 'n verpligte 24 dae blootstelling aan -0,6°C om moontlike insek-larwes te dood gedurende die uitvoer na markte soos die VSA en China, maar hierdie protokol veroorsaak koueskade. Die doel van hierdie studie was eerstens om die invloed van verskillende voor-oes faktore op koueskade-sensitiwiteit van nawel lemoene te bepaal. Daarbenewens is naby-infrarooi (NIR) spektroskopie as 'n potensiële tegniek getoets om variasie in koueskade-sensitiwiteit van nawel lemoene te identifiseer, en laastens is die effektiwiteit van thiabendazole (TBZ) toediening in die verpakkings lyn, om koueskade te verminder, ondersoek. Verskillende faktore soos kultivar, mikroklimaat, oesdatum, vruggrootte en skilkleur beïnvloed die koueskade-sensitiwiteit van sitrus. Hierdie studie het bevind dat die ‘Washington’ meer sensitief is vir koueskade as die ‘Navelina’ nawels. Vrugte afkomstig uit die koudste deel van Citrusdal (Tharakama) het die hoogste voorkoms van koueskade. In die algemeen was vrugte ge-oes in die middel van die kommersiële-venster die minste koueskade-sensitief, maar interne rypheid hou nie verband met koueskadesensitiwiteit nie. Naby-Infrarooi (NIR) spektroskopie is getoets as 'n potensiële instrument om vrugkwaliteit parameters te voorspel met betrekking tot koueskade. Deur ontleding van die NIR data met behulp van ‘Principal Components Analysis’ kon vrugte groepeer word volgens posisie (binne vs. buite blaredak), groottes en skilkleur. Deur ‘Partial Least Square Regression’ verdere data ontleding en met inagneming van vrugkwaliteit parameters (fermheid, skil kleur en massa), kon die NIR spektra wat verkry was egter nie 'n goeie voorspelling model vir koueskade verskaf nie. TBZ verminder die voorkoms van koueskade van sitrusvrugte na dit toegedien was in 'n semi-kommersiële verpakkingslyn in die waks, ‘drench’ of baddens. Die toediening van verskillende swamdoders van die TBZ chemiese groep in baddens, het aangedui dat die TBZ doop behandeling effektief was om die voorkoms van koueskade te verminder. Daarbenewens was TBZ meer effektief in verlaging van koueskade as dit toegedien word in warm (40°C) as koue (10°C) water, asook teen die volle (20mL.L-1) en die helfte van die aanbevole kommersiële dosis. Wakstoediening was effektief in die vermindering van die voorkoms van koueskade en byvoeging van TBZ in die waks het die effektiwiteit verhoog. Die suksesvolle vermindering van koueskade tydens kommersiële verskeping van sitrusvrugte moet egter nie fokus op 'n enkele faktor nie, maar op 'n strategie wat bestaan uit voor-oes faktore wat die vrugskil kwaliteit beïnvloed, sowel as spesifieke na-oes tegnologieë en hanteringsprotokolle wat bekend is vir die vermindering van koueskade. / Citrus Research International

Thesis (MComm)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: There is great concern in the fruit industry that too much fruit and money is lost each year due to breaks occurring in the export cold chain of fresh fruit. Therefore, the CSIR (Council for Scientific and Industrial Research) and Stellenbosch University were approached to do research on this problem. This particular study focuses on the cold chains of table grapes, summer pears and plums as these fruit are especially sensitive to temperature. Observations were made on fruit farms, in pack houses, in cold stores as well as in the Port of Cape Town. From these observations it was clear that protocols are not always followed and fruit quality is sometimes neglected because of pressure to speed up the exporting process. In order to analyse the export cold chains of these fruit types, temperature trials were conducted and temperature data received from exporting companies was analysed. The data was analysed from the cold store up to the point where the vessel sailed out of the Port of Cape Town. From the analysis it became clear that too many cold chain breaks occur during fruit exports from South Africa, especially during the loading of containers at cold stores. As a final output to the study, a good cold chain practice guide for the export of table grapes was developed with the aim of assisting the fruit industry in minimizing these cold chain breaks. The guide was developed with simplicity to ensure easy understanding under all role-players in the industry. This study was a small step in the right direction, but it should be highlighted that the complexity of the problems in the fruit cold chains are substantial and further research will have to be done in order to eliminate the occurrence of these cold chain breaks.

Thesis (MPhil)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The implementation of the Marketing of Agricultural Products Act of 1996 resulted in the deregulation of the South African fruit industry in October 1997. This led to independent decision-making regarding the marketing of export products by a host of deciduous fruit producers and exporters. No longer were the producers controlled by a monopoly. The deregulation challenged the inflexible single-channel fruit pooling marketing structure of the past and exposed domestic producers and exporters to the competitive global fruit market. By implication this translated into a need to become globally competitive in the interest of growing market share. The focus of this new marketing system is to give the producer the opportunity to export high quality fruit and earn an associated premium for his products, and to strengthen his brand and reputation through these efforts. The deregulation also provided the opportunity for independent fruit growers to influence the optimisation of the value chain, in the interest of lower costs and improved customer service. The market has since changed from supply (stock "push") to demand driven (stock "pull"). It is now imperative that the various producers and exporters provide an efficient supply chain in order to satisfy the end user demands. A consequence of this would be the increase in deciduous fruit quality as a determinant of decidU<;ms fruit demand. Market research was conducted to determine the impact that deregulation has had on South Africa's deciduous fruit industry and to establish the degree to which Portnet should transform to accommodate this changing and deregulated environment. In summary, deregulation has created many opportunities for South African fruit producers and exporters in the domestic and international markets. The only impediment is whether the new logistical structures will be able to reduce costs and improve profit margins, particularly now that economies of scale have been dissipated. Customer service may improve, but at what cost? / AFRIKAANSE OPSOMMING: Die implementering van die Bemarkingswet van Landbouprodukte in 1996 het gelei tot die deregulering van die Suid-Afrikaanse vrugtebedryf in Oktober 1997. Die gevolg hiervan was die onafhanklike besluitneming ten opsigte van die bemarking van uitvoerprodukte deur 'n groep sagtevrugteprodusente en -uitvoerders. Die produsente is nie langer deur 'n monopolie beheer nie. Die deregulering het die onbuigbare een-kanaal vrugtebemarkingstruktuur van die verlede opsy geskuif en binnelandse produsente en uitvoerders die geleentheid gebied om deel te word van die kompeterende intemasionale vrugtemark. Dit het by implikasie aanleiding gegee tot 'n behoefte om intemasionaal mededingend te wees in die belang van 'n groeiende markaandeel. Die fokus van hierdie nuwe bemarkingstelsel is om die produsent die geleentheid te gee om hoe kwaliteit vrugte uit te voer en die meegaande hoe premie vir sy produkte te verdien, asook om sy handelsmerk en reputasie sodoende te vestig. Die deregulasie het ook die onafhanklike vrugteprodusente die geleentheid gegee om seggenskap in die optimisering van die waardeketting te kry wat tot laer koste en verbeterde klientediens gelei het. Sedertdien het die mark verander vanaf 'n aanbodmark na 'n vraaggedrewe mark. Dit is nou uiters belangrik dat die verskillende produsente en uitvoerders 'n effektiewe voorsieningsnetwerk skep om in die eindverbruikers se behoeftes te voorsien. Die gevolg sou 'n toename in die gehalte van sagtevrugte wees, wat weer belangrike determinant van die sagtevrugte vraag is. Marknavorsing is gedoen om die impak van die deregulasie op die Suid-Afrikaanse sagtevrugtebedryfvas te stel. Wat ook vasgestel moes word, was die mate waartoe Portnet moet transformeer om in die veranderde en gedereguleerde omgewing te funksioneer. Om op te som, deregulering het verskeie geleenthede vir Suid-Afrika se vrugteprodusente en uitvoerders in die binnelandse en intemasionale markte geskep. Die enigste vraag is of die nuwe logistieke strukture wel koste sal verminder en winsmarges sal verhoog, veral noudat skaalvoordele nie meer van toepassing is nie. Klientediens sal verbeter, maar teen watter koste?

Content removed due to copyright restrictions: Smale, N.J. Tanner D.J., Amos N.D., Cleland D.J. (2003). Airflow properties of packaged horticultural produce - a practical study. Acta Horticulturae, (599), 443-450 / Horticultural exports are of economic significance to New Zealand. Only through providing consistently high quality products to distant markets can New Zealand hope to command a premium price. New Zealand's two major horticultural exports, apples and kiwifruit, are transported to foreign markets by sea; either in refrigerated holds on-board cargo vessels or in refrigerated containers. Long transit times mean that conditions in these systems must be carefully controlled to ensure high quality product arrives at market. Effective distribution of air is a key consideration in transport systems. A mathematical model to describe the flow of air in marine transport systems was developed. The model was based on a resistance network framework, relying on simplification of the complex geometry within the refrigerated space to a discrete number of flow paths and points of convergence and divergence. Correlations quantifying the flow resistance of each channel were required. Some of these correlations were already available, and some were developed specifically for this purpose. A general method for predicting the flow resistance of enclosed conduits based on the Darcy-Weisbach, laminar and Colebrook equations was found to be sufficiently accurate for use. The flow resistance of horizontally vented horticultural packages was quantified and the cause of the flow resistance investigated. Entrance and exit effects were found to be significant, and a relationship between vent size and flow resistance was developed. Air interchange between a vented carton and the general refrigerated space was shown to be a significant mode of heat transfer. The effect of vent design on the rate of air interchange was found to be complex. Quantitative relationships between vent characteristics and rates of air interchange could not be developed; however, some general observations were made. Vent size, aspect ratio and alignment were all found to affect the rate of interchange. An existing method for determining in-package fluid velocities was refined to improve the accuracy of data and reduce the measurement time. A low-cost method for measuring airflows in transport systems was also developed utilising thermistors. These thermistor anemometers were used to monitor velocities in four shipments of fresh produce from New Zealand. Three of the four vessels monitored showed large variation in the circulation rate in the period between evaporator defrosts due to frosting. In some cases, frosting was severe enough to cause loss of delivery air temperature control. Management of defrosts was identified as an area of improvement in refrigerated hold management. Validation of the model developed was performed using four systems: a laboratory scale test-rig, a 40' container and two of the surveyed refrigerated holds. Airflow predictions were used with a heat transfer model to predict in-package temperatures. Comparison of measured and predicted flows and in-package temperatures showed good agreement given uncertainty of geometry and input data. The implications of altering a number of operational and design variables in both containers and refrigerated holds were investigated using the developed models. Increased circulation rates were found to increase cooling rates and reduce temperature variability in both types of systems; however, the magnitude of the benefit decreased with increasing circulation rate. Removal of the floor gratings and the use of pallet bases as an air distribution channel was found to increase temperature variability in both types of systems. The magnitude of the increase was small in a 40' container but substantial in a refrigerated hold. The correlations and models developed in this thesis provide useful tools to analyse and optimise the design and operation of refrigerated marine transport systems.

Orientador: Antonio Carlos de Oliveira Ferraz / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-12T09:36:15Z (GMT). No. of bitstreams: 1 Yokoyama_LucianeYumiRosa_M.pdf: 764510 bytes, checksum: 449c6db1fffebe07c86cb609f147db2e (MD5) Previous issue date: 2004 / Resumo: Figos são suscetíveis a danos, pois oferece pouca resistência à solicitações mecânicas. Por isso, este trabalho teve como objetivo avaliar os efeitos do transporte na qualidade do figo 'Roxo de Valinhos' e investigar parâmetros extraídos da curva força e deformação, para se obter um índice de firmeza de menor variabilidade para o figo.Figos foram acondicionados em bandejas de papelão (tradicional), em bandejas plásticas com divisões individuais, e plásticas com divisões individuais, forradas com algodão em cada divisão e também depositadas sob uma camada de algodão. As bandejas foram colocadas em engradados de madeira para permitir empilhamento. As embalagens foram dispostas nas posições dianteira e traseira da carroceria do caminhão, e nas posições inferior e superior da pilha. Os engradados, contendo as bandejas plásticas forradas com algodão, foram colocadas no centro da carroceria e na parte inferior do empilhamento.O percurso se iniciou numa propriedade em Valinhos, seguindo até a CEAGESP - São Paulo/SP. Na CEAGESP, as embalagens foram descarregadas e pesadas, e logo à seguir foram conduzidas ao laboratório da FEAGRI-UNICAMP - Campinas/SP. Após armazenamento mediu-se a perda de massa, aparência, firmeza, sólidos solúveis/acidez titulável e avaliou-se o extravazamento do conteúdo celular durante o armazenamento em condições ambientais. Observou-se que os figos, independente do tipo de embalagem, apresentaram excessiva perda de massa 24h após o transporte. Para a aparência, os figos transportados em bandejas de papelão apresentaram marcas de contato entre frutas e marcas de superfície, e os das bandejas plásticas apresentaram manchas de umidade na casca proveniente da transpiração do fruto, e abrasões causadas pelo contato com as paredes das divisões. A variabilidade dos valores de força e energia específica a 10% de deformação apresentaram pequena diferença entre si, devido a semelhança de comportamento foi adotada o valor de energia de deformação como índice de firmeza. Não houve diferenças de perda de massa, aparência, firmeza, sólidos solúveis, e de extravazemento do conteúdo celular entre posições no caminhão. / Abstract: Figs are commodities that are highly susceptible to damages. The main purpose of this study was to evaluate the effects of transportation on the quality 'Roxo de Valinhos' figs and also to investigate parameters of the force and deformation curve in order to obtain a firmness index with low variability. Figs were conditioned in traditional cardboard trays, plastic trays with unitary divisions and plastic trays with uniting divisions, lined with cotton in each division and also between the crate and the tray. The packings were disposed on a truck plattaform in the front and back positions, and in inferior and superior positions of the pilles. The packings - with the lined plastic trays - were placed at the center of the plattaform and at inferior part of the pile. The journey initiated in a property in Valinhos and ended at CEAGESP - Paulo/SP. At CEAGESP the packings had been unloaded and weighed and then they taken to the laboratory at Feagri-Unicamp - Campinas/SP where they were kept at room temperature. Mass of loss, appearance, firmness, soluble solid /acid ratio of the figs and cellular leakage content after transport were mesuared and avaluated storage. It was observed the figs, independent of the tray type, presented extreme loss of mass 24h after transportation. For the appearance the figs packed in cardboard trays showed marks of contact between fruits and surface marks and the ones in the plastic trays showed humidity marks from the perspiration of the fruit and abrasions caused by the contact with the walls of the divisions. Values of force and specific energy 10% of deformation showed similar variability, than were adopted as index firmness the values of the deformation energy. There were no significant differences of loss of mass, appearance, firmness, solids and acidity and of cellular leakage content between the various positions inside the truck. / Mestrado / Maquinas Agricolas / Mestre em Engenharia Agrícola

Thesis (MCom)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The South African fresh fruit export industry is concerned about fruit and financial losses due to temperature breaks within the fresh fruit export cold chain. The Port of Cape Town plays a crucial role in the export process as the majority of fruit reefer containers that are exported through Cape Town are handled by the Cape Town Container Terminal. This study focuses on the container terminal leg of the fresh fruit export process. Observations made in the Cape Town Container Terminal, at shipping lines and exporting companies show that certain procedures are not always followed in the Cape Town Container Terminal and that congestion and ineffective working methods are causing breaks within the fresh fruit export cold chain. Temperature and time data received from Transnet Port Terminals, shipping lines and exporting companies were analysed for the container terminal segment of the export process. From the data analysis it is clear that there are a large number of breaks originating within the container terminal and that the port is not operating efficiently. The study identifies areas of improvement and makes recommendations on improving some of the issues discussed.