Implementation of food safety programmes has been difficult for small and medium sized companies (SMEs) in Cyprus, taking into consideration specific practises witnessed as common place amongst Cypriot food producers. SMEs tend to have a poor understanding of food management systems and limited adoption and implementation. The requirement for full food management implementation and the replacement of the national standards by the new ISO22000 in 2006 placed an even greater burden on these businesses. The aim of this project is to compare food safety and hygiene before, during, and after implementation of food management systems assessing whether the implementation of food management systems in SMEs in Cyprus improves the hygiene and compliance with food safety requirements. A questionnaire survey was made of 50 SMEs (food industry sector) and an audit process was carried out, in companies that had not started the implementation of food management systems but intended to do so. Follow-up audits to the premises observed the process and the operatives to determine any changes to the level of food safety and hygiene. A benchmarking audit was carried out before, during, and after implementation of the system, and each company was rated. Results show that most respondents encountered many problems in applying and maintaining food management systems. Even if food management systems were applied, businesses did not alter their daily practices in a significant way. To conclude, in order for small food enterprises to have in place workable food management systems, a generic, simple, and flexible food management system must exist. In addition, each enterprise has its own application limit regarding the complexity of the system. When this limit is exceeded negative results appear for the enterprise.

Surimi is a concentrated myofibrillar protein added with several additives. It has been used by seafood industries as an intermediate product to produce various seafood analogues. Due to the current increase in health awareness, consumer demands healthier and less sweeter surimi. The objective of this study is to investigate the rheological and textural properties of surimi added with different types of additives which is sugar, salt and sago starch. This study is also done to determine the possibility of reducing the amounts of additives added to surimi. Sago starch as an additive to improve the rheological and textural property of surimi is studied. Another concern in the surimi industry is the washing process. The 3 washing cycle procedure produces large amount of water waste. Thus, this study is done to understand the effects of reducing the washing cycle and using nanobubble water on surimi. Results obtained from this research shows that mannitol yields the best results when compared to sucrose and sorbitol. Surimi with 4% (w/w) salt concentration yields the highest gel strength. However, surimi with 1% (w/w) salt concentration which possesses a lower gel strength showed frozen stability up to 6 months. Sago starch was found to increase gel strength up to 11 0%. Washing using medium concentrated nanobubble water ( 11.15 x 1 08 bubbles/ml) was found to display a high gelling strength with only 2 washing cycle compared to using distilled water.

This thesis aims to develop a better understanding of both the formation and properties of fluid gels using the microstructural engineering approach. In general terms, the two main outcomes of this research are: (1) advancing the knowledge on the structuring processes for fluid gel design and (2) developing new models for the structure-function relationship for fluid gels. There is currently a lack of understanding on the formation of thermo-stable fluid gels due to the absence of processing techniques for their production. In this thesis, two processing techniques were developed to produce thermo-stable fluid gels from alginates. The first technique is a continuous process comprising a pin stirrer device with a Ca2+-injection system. The second production technique used a cup and vane rheometer combined with an internal gelation method. With this technique, the kinetics of fluid gel formation was studied as function of applied shear rate, calcium concentration and alginate molecular weight. With regard to the structure-function relationship, the lubricating behaviour of agar fluid gels was explored using a new approach which consisted in decoupling the contributions of the continuous phase and the particulate gelled phase. The effect of added co-solutes on lubricating properties of agar fluid gels was also explored.

Minimisation of Pt loading in proton exchange membrane fuel cells (PEMFCs) is important because Pt is expensive and its supply is limited. Nanoparticle aggregation is a problem because aggregated nanoparticles have a lower surface area and so exhibit lower mass activity than well dispersed nanoparticles. In the present work platinum nanoparticles were successfully prepared, by an aqueous colloidal route, using tetradecyltrimethylammonium bromide (TTAB) and nonylphenolethoxylate (NP9). Such organic molecules which adsorb on the surface of nanoparticles are generally regarded as undesirable species which block catalytic sites and slow reaction kinetics. However, removal processes cause particle aggregation. Here the performance of catalysts was studied using a rotating ring disc electrode (RRDE), without extensive removal of surfactant. Nanoparticles prepared using NP9 surfactant showed catalytic activity for the oxygen reduction reaction (ORR) similar to the commercial catalyst (TKK) but TTAB had a strong poisoning effect. Finally the performance of the Pt+NP9 nanoparticles was compared with the commercial catalyst (TKK) using single cell MEA testing. The main difference in performance was in the mass transport region of the polarisation curve. The conclusion was that surfactant stabilization of Pt nanoparticles is important to fuel cell performance, while subtle effects of molecular structure on catalytic activity require more investigation.

The object of the work was to attempt to propose an improvement in the process of vapour-liquid contacting with particular reference to commercial distillation. The literature was reviewed by considering both the overall performance data of the methods and devices used for contacting and the more fundamental studies of the mechanisms and effects taking place in them. It was concluded that the cross-flow Sieve tray with a high free area and many small holes would offer the best performance. This solution, however, is not commercially viable as the cost of producing a device to these specifications by conventional means would be excessive. To overcome this economic restraint and to retain the improved performance, a cheaper method of tray floor construction was proposed in which the material used was inherently porous. Many materials satisfy the requirements for use as a tray floor, for example, open cloths, meshes and gauzes and open cell foam and sintered materials. Sorting tests were, therefore, performed on a small scale, using an air-water system, to eliminate those materials which gave unsatisfactory hydraulic performance. A 68" x 14" column, also using an air-water system, was employed to test the feasibility and the hydraulic performance of the proposed tray floors on a large scale. The same apparatus was then used to determine the liquid mixing characteristics of the most promising material. To discover the performance of the new trays under actual vapour-liquid conditions, a 12" diameter, three tray distillation column was built and used experimentally. The separation efficiencies and tray pressure drops were evaluated for total reflux conditions at various vapour rates and outlet weir heights using the systems toluene n-heptane and toluene methyl-cyclo-hexane. The results for the new glass cloth trays showed that better performance could be obtained than conventional trays, particularly with regard to the flexibility. Various interesting phenomena manifested themselves in marked differences between the results obtained for the same material using the air-water and the hydrocarbon systems. The factors and their effects which produce these phenomena were, therefore, studied using various systems and glass cloths in a 3" diameter column.

The objective of this research was to investigate adhesion of different fouling deposits with different contact surfaces using atomic force microscopy (AFM). In this thesis, AFM has been employed to measure: (i) The adhesive interactions between a colloidal silica microparticle and stainless steel, PTFE-coated stainless steel, glass and ceramic surfaces, in the presence of a number of solutions and suspensions of ingredients found in commercially available toothpaste. (ii) To compare the measurements from the AFM and micromanipulation to see the differences and similarities. The micromanipulation technique was developed to measure the adhesive strength of different deposits. The method uses a T-shaped probe made of stainless steel chip, dimension 30 x 6 x 1 mm connected to the output aperture of a transducer (Model BG-1000, Kulite Semiconductor, Leonia, NJ. USA) which was itself mounted on a three dimensional micromanipulator (MicroInstruments, Oxon, UK). The two measurement methods are capable of giving quantitative results for the strength of the forces involved in adhesion; fast moving consumer goods (FMCG) deposits, toothpaste and confectionary stimulant deposits have been studied, and their interactions with stainless steel, glass and PTFE surfaces measured. (iii) Further investigation of AFM adhesion measurements, with caramel, whey protein and sweet condensed milk (SCM) deposits after heating at 30ºC, 50ºC, 70ºC, and 90ºC. The two selected spherical microparticles used were stainless steel and PTFE, which were attached to the end of an AFM tip. The data shows that, for removal in all cases using micromanipulation, the pulling energy increases with increasing height above the surface and the slope of the lines of pulling energy versus thickness is similar. Stainless steel shows the highest pulling energy with slightly higher energies than glass and PTFE, whilst PTFE show the lowest interaction. For the AFM data, PTFE again gives much lower adhesion forces. This is due to the different molecular interactions between different surfaces and caramel. There is thus partial agreement between the two methods. The micromanipulation method measures a range of parameters – such as the deformation and flow of the deposits, and so it might not be expected that there would be complete agreement. Here stainless steel and glass show very similar behaviour, as opposed to the differences seen using AFM; the different surface roughness of the two materials might also be expected to have an effect. At different temperatures the results from the different contact positions on the deposits; with an approach speed to the deposits for all experiments was 3μm/s, then a 5 second pause on the deposit and then the rate of retract was 0.25μm/s. Significant (more than an order of magnitude) differences are seen between forces for the same and different deposits, and between different surfaces for the same deposits. Lower forces are seen at 90ºC in all cases; at the higher temperature, the force between surface and deposit is less. To design systems to resist fouling, these results suggest that measurements at different process temperatures are needed; data at room temperature has overpredicted the interactions. The results suggest that the AFM force curve measurement technique could be used to study a variety of food deposits that have undergone different processing conditions. The method can help in optimising removal of food deposits in terms of food cleaning protocols. AFM could be a valuable technique in measuring surface properties, and in relating behaviour to surfaces. The capability of the AFM to provide better understanding of materials structure, surface characteristics and the interactive forces at the meso- and nanoscale level. The AFM will enhance the understanding of large-scale engineering processes, especially as materials are increasingly being designed down to the submicrometre level.

The potential to improve the performance of polymer composites cost-effectively has been researched across various aspects of development and manufacture. Each endeavour fell broadly into one of three categories; the principal ingredients and their required properties, the methods with which they were transformed into products and the means by which they were observed. It was determined that the ingredients with the highest potential as defined, each shared simplicity and abundance as material traits. The use of bespoke functionalised ingredients proved costly to implement, providing only modest property benefits compared to a standard formulation comprising polypropylene, 10 – 30 % w/w of 2 μm calcium carbonate with 0.5 – 1.0 % w/w stearic acid surface treatment. It was found that an apparent deterioration in impact resistance that was encountered on reducing the filler particle size was in each case observed, attributable to a coarsening of these fine particles that resulted from the mixing process. Finer particles could not be implemented more cost-effectively than standard formulations; an effect which was attributed to the tendency of the finest particles to form aggregates that could not be decomposed by mixing under high shear. However, the favourability of particle dispersion in standard formulations was used to implement a production method of polymer composites that required significantly less energy across the entire production stage and held other significant advantages. Concentrates comprising minerals in wax were produced and made to successfully re-disperse from loadings approaching those allowed by their theoretical packing maxima, in some cases up to 90 % w/w. Furthermore, a single injection moulding cycle with minimal back-mixing was used to combine concentrates and neat polymers to make commercially-competitive composite specimens, at final concentrations as low as 10 % w/w. A principal method to obtain in situ visual particle data from thin composite films was developed along with several derivative analyses. The techniques allowed rapid and representative data collection for high particle proportions at resolutions of 6 – 8 μm, accounting for particles most relevant to impact-resistance in standard formulations. As a whole, significant and realistic saving opportunities were identified in the expenditure of unnecessary resources, such as; processing energy, capital investment, transportation, labour and time. These findings were supported by experimental data.

The aim of this work is to better understand the structuring processes in low fat dairy emulsions. Model sodium caseinate-galactomannan aqueous two-phase systems (NaCAS-GM ATPS) differing in GM-type (locust bean gum (LBG), tara gum (TG), guar gum (GG), fenugreek gum (FG)) and added sugar (trehalose, sucrose, glucose and fructose) were studied by the phase-volume ratio method, rheooptics, and droplet retraction method on phase equilibria, flow behaviour and interfacial properties, respectively, at pH 5.8 and 20°C. The results revealed that the presence of sugar in concentrations 5-40 wt% resulted in an increase in cosolubility of the phases and a decrease in interfacial tension (σ). Sugar concentrations > 40 wt% decreased cosolubility. Based on the mannose:galactose ratio of GM and type of sugar (added in concentration 15 wt%) the best cosolubility and corresponding smallest σ was attributed to FG and trehalose, respectively. The flow of ATPS depended on quiescent microstructure, the shear and physical properties of the phases. In polysaccharide-continuous ATPS, the occurrence of a shear-induced phase inversion event was observed for 0- 20 wt% sugar. A further increase in sugar concentration >20 wt% was found to suppress this phenomenon due decreased viscosity ratio and formation of thread like structures in flow.

The tablet is the preferred route of delivery for pharmaceutical products to its relative ease of manufacture and high patient compliance. However, complex tablet formulations can present a number of process challenges, necessitating careful design of both the formulation and the process. This thesis sets out to investigate some of the issues involved with the lubrication of roller compaction formulations in order to gain a greater understanding of the role of lubrications. A systematic study on the effect of magnesium stearate during feeding and compaction in a horizontally fed roller compactor has been conducted. The feasibility of a novel external lubrication was investigated as an engineering solution to prevent adhesion to roll surfaces in the absence of magnesium stearate from the formulation. Alternative formulation strategies and lubricants have been investigated to find suitable materials that provide similar lubricating properties to magnesium stearate whilst exhibiting less detrimental effects on the tablet strength and tablet dissolution. The feasibility of using surrogate APIs as an aid to facilitate process and formulation design of investigational drug products was tested using a statistical analysis of the response data obtained from an experimental design.

The focus of this thesis is the role of the solvent and scale-up upon rate and selectivity in heterogeneous catalysed hydrogenations, which are ubiquitous in the production of fine chemicals and pharmaceuticals. A kinetic method has been developed based on rigorous statistical methods and sensitivity analysis for the catalytic hydrogenation of 4-phenyl-2- butanone in stirred tank reactors at two different scales using Pt/TiO2 and Pt/SiO2 catalysts. In this thesis, modelling carried out for a 100 mL scale reactor was validated against experimental data supplied by Queens University Belfast (QUB). Experimental measurements of rate and selectivity and model validation at a larger 3000 mL scale were both carried out as part of this study. The models were evaluated over a wide range of operational conditions at both scales for Pt/TiO2 catalyst, and by using a systematic kinetic methodology it was possible to identify the dominant reaction route, derive physiochemically meaningful kinetic data and a reduced kinetic model that was applicable to the scale-up. Comprehensive kinetic analysis made it possible to gain some insight into the shift in reaction mechanism upon scale-up. Kinetic investigation of solvent effects was also carried out at the 100 mL scale for a range of solvents (protic, aprotic polar, apolar, ethers, and halogens) and both catalysts, again tested against experimental data supplied by QUB. The dominant effects of solvent on rate and selectivity of the chosen reaction system were identified as the degree of active site availability imposed by competitive adsorption of solvent on catalyst and the extent of which the solvents assist the product desorption from catalyst surface. The solvent effects upon scale-up give the remarkable result of a significant shift in the selectivity of the catalyst towards phenyl ring and ketone hydrogenation groups of 4-phenyl-2-butanone.