Yes / The use of Reverse Osmosis (RO) membrane processes for the clarification and the concentration of apple juice is proposed as an alternative to the conventional concentration technique, which is based on evaporation and freezing. Several models have been published on RO process models relying on different assumptions that predict the permeate flux and aroma compounds rejections for aqueous solutions apple juice. The solution-diffusion model (Lumped model) has been applied for the previous models. The main instrument of this study is the use of the gPROMS software to develop a new distributed steady state model that will relax a number of earlier assumptions. The model has been validated with an observational data of apple juice filtration derived from the literature by analysing the permeate flux and the performance of membrane rejection at different concentrations, temperatures and pressures for a laboratory scale of spiral-wound RO module. Simulated results corroborate with experimental and model predictions.

Yes / Reverse Osmosis (RO) membrane process has been commonly used for clarification and concentration of apple juice processes, due to significant advance in membrane technology, requirements for low energy and cost, and effective retention of aroma components. In this paper, a multi-stage RO industrial full-scale plant based on the MSCB 2521 RE99 spiral-wound membrane module has been used to simulate the process of concentrating apple juice and to identify an optimal multi-stage RO process for a specified apple juice product of high concentration measured in Brix. The optimisation problem is formulated as a Nonlinear Programming (NLP) problem with five different RO superstructures to maximise the apple juice concentration as well as the operating parameters such as feed pressure, flow rate and temperature are optimised. A simple lumped parameter model based on the solution-diffusion model and the contribution of all sugar species (sucrose, glucose, malic acid, fructose and sorbitol) to the osmotic pressure is assumed to represent the process. The study revealed that the multi-stage series RO process can optimise the product concentration of apple juice better than other configurations. It has been concluded that the series configuration of twelve elements of 1.03 m2 area improves the product apple juice concentration by about 142% compared to one element. Furthermore, the feed pressure and flow rate were found to have a significant impact on the concentration of the apple juice.

Reverse Osmosis (RO) is a membrane-based separation process applied in several industrial and food processing applications. In this research, performance of RO process is investigated in respect of two applications (a) wastewater treatment (b) concentration fruit juices using model-based techniques. For this purpose, a number of models (both 1 and 2-dimensional steady state and dynamic) for spiral wound RO process are developed based on Solution-Diffusion model and Irreversible Thermodynamic model. The models are validated against actual experimental data reported in the literature before being used in further simulation and optimisation studies for both wastewater treatment and fruit juice concentration. Wastewater effluents of many industrial applications contain a variety of micro-pollutants and highly-toxic compounds, which are released into a variety of water resources. Such pollutants not only disrupt the biological ecosystem, but they also pose a real threat to the water supply for human consumption and to the aquatic ecosystems. The earlier chapters of the thesis evaluate the performance of RO process in terms of removal efficiency of toxic compounds such as chlorophenol, N-nitrosamine, etc. from wastewater. The effect of several operating parameters such as feed pressure, concentration, flow rate and temperature, on the performance of RO process are evaluated. Also, suitability of a number of different RO configurations for efficient removal of toxic compounds are evaluated. For example, (a) two-stage/two-pass RO design synthesis of RO network for the removal of chlorophenol (b) multistage multi-pass RO process with and without energy recovery option for the removal of N-nitrosamine are investigated. The dynamic response of the RO process for step changes in the operating parameters is investigated for the removal of phenolic compounds. Finally, in the context of wastewater treatment, a case study with multi compounds contaminants is suggested where a multi-objective optimisation problem has achieved the optimum rejection of all the compounds and recovery rate. In respect of food processing, RO has been considered as a prominent process in fruit juice concentration due to its ability to effectively retain the flavour, sensory, aroma and nutritional characteristics and concentrate the juice. This research elucidates one example of apple juice concentration process and focuses on highlighting successful modelling and optimisation methodology. This in turn provides an efficient method of RO process for concentrating apple juice by improving the reliability and efficiency of the underlying separation and concentration process. / Ministry of High Education and Scientific Research of Iraq

<p dir="ltr">Global food demand increases rapidly as a result of continuously growing population has raised severe concerns with food security. To overcome this critical challenge, food systems must be transformed to produce food with not only higher yield but also better nutritional quality. Therefore, food processing, as a critical step in food production chain that turn agricultural products into food, needs to be innovated through applications of cutting-edge technologies.</p><p dir="ltr">Microbubbles (MBs) are tiny gas-filled bubbles with distinctive physicochemical characteristics, including slow rising speed and long lifetime in liquid, large surface area per unit of gas volume, high internal pressure, high gas dissolution rate, hydrophobic and negatively charged surface and production of reactive oxygen species. Additionally, MB dispersion can enhance the heat and mass transfer properties of liquid. These features have led MBs to numerous applications in the fields of disease treatment, anaerobic digestion, and wastewater treatment, however, their applications in food processing have not thoroughly explored.</p><p dir="ltr">In this dissertation, MB technology was applied to different unit operations of food processing, including freezing, concentration and extraction, and the effects of MBs on process efficiency and food product quality were comprehensively studied. In the first study, MB-infused freezing medium was used for grape tomato immersion freezing. MBs markedly reduced the drip loss of tomato by 13.7–17.0% and improved its firmness, which were correlated to the accelerated nucleation process and formation of small ice crystals during freezing. The impact of MBs on water evaporation during apple juice concentration was investigated in the second study. MBs dramatically enhanced water evaporation, and concentration at bubble gas temperature of 40 °C and juice temperature of 70 °C showed the largest increase in the evaporation rate, by 104%. Moreover, although air-MBs showed an oxidation effect on both frozen tomato and concentrated juice, N₂-MBs were found to be an ideal alternative which much better preserved the nutritional values of processed foods. Lastly, MBs and cold plasma-MBs were incorporated into citric acid solution for extracting pectin from apple pomace. MBs present in extracting solvent increased the extraction yield by 18–21%, and extraction with plasma-MBs showed even higher yields by up to 30%. Additionally, MB and cold plasma-assisted extraction were found more effective in extracting complex RG-I pectin.</p><p dir="ltr">This dissertation develops various approaches to incorporating MBs into conventional unit operations and enhancing their performance. With these novel applications explored, MB technology will not only increase the productivity but also reduce the energy, water and chemical use of food processing. Ultimately, MB-assisted processes are expected to play an important role in improving the sustainability of the food industry.</p>