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Dr. Valentina Stojceska
Department of Mechanical Engineering, Brunel University London, London, UK

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0 Energy Efficiency
0 Food Systems
0 Life Cycle Assessment
0 Sustainability
0 waste valorisation

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Review
Published: 16 March 2020 in Trends in Food Science & Technology
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The conventional drying technologies presently used in the food industry are hot-air based systems that are normally considered as an energy intensive processes with higher green-house gas emissions and accounting approximately 15% of the overall manufacturing expenses. The most common drying processes used for the preservation of the food materials are conventional thermal drying which proved to be a high energy consuming process. With the world progressing towards the application of green technology and sustainable methods, the use of alternative energy efficient drying systems are of paramount importance. This paper extensively reviewed the energy efficiency and techno-economic performances of a number of non-conventional drying technologies that are currently used in the food industry for drying of the food materials. The reviewed drying technologies include: hybrid systems, heat pumps, super – heated steam, vacuum, microwave, refractance window®, electrotechnologies, ohmic, adsorption mediated and impingement. It was found that the hybrid drying systems with the solar drying input and refractance window® drying were among the most promising energy efficient drying methods that could be potentially used for drying of the food materials in industrial processes.

ACS Style

Abhay Menon; Valentina Stojceska; Savvas A. Tassou. A systematic review on the recent advances of the energy efficiency improvements in non-conventional food drying technologies. Trends in Food Science & Technology 2020, 100, 67 -76.

AMA Style

Abhay Menon, Valentina Stojceska, Savvas A. Tassou. A systematic review on the recent advances of the energy efficiency improvements in non-conventional food drying technologies. Trends in Food Science & Technology. 2020; 100 ():67-76.

Chicago/Turabian Style

Abhay Menon; Valentina Stojceska; Savvas A. Tassou. 2020. "A systematic review on the recent advances of the energy efficiency improvements in non-conventional food drying technologies." Trends in Food Science & Technology 100, no. : 67-76.

Journal article
Published: 16 December 2019 in Sustainability
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High Concentrator Photovoltaic Thermal (HCPV/T) systems produce both electrical and thermal energy and they are efficient in areas with high Direct Normal Irradiance (DNI). This paper estimates the lifecycle environmental impact of the HCPV/T 2000x system for both electrical and thermal functionalities. Process-based attributional method following the guidelines and framework of ISO 14044/40 was used to conduct the Life Cycle Assessment (LCA). The midpoint and endpoint impact categories were studied. It was found that the main hotspots are the production of the thermal energy system contributing with 50% and 55%, respectively, followed by the production of the tracking system with 29% and 32% and the operation and maintenance with 13% and 7%. The main contributor to the lifecycle environmental impact category indicators was found to be the raw materials acquisition/production and manufacturing of the thermal energy and tracking systems. The results indicate that the lifecycle environmental impact of the HCPV/T 2000x system is lower compared to fuel-based Combined Heat and Power (CHP) and non-Renewable Energy Sources (non-RES) systems.

ACS Style

Emmanuel Shittu; Maria Kolokotroni; Valentina Stojceska. Environmental Impact of the High Concentrator Photovoltaic Thermal 2000x System. Sustainability 2019, 11, 7213 .

AMA Style

Emmanuel Shittu, Maria Kolokotroni, Valentina Stojceska. Environmental Impact of the High Concentrator Photovoltaic Thermal 2000x System. Sustainability. 2019; 11 (24):7213.

Chicago/Turabian Style

Emmanuel Shittu; Maria Kolokotroni; Valentina Stojceska. 2019. "Environmental Impact of the High Concentrator Photovoltaic Thermal 2000x System." Sustainability 11, no. 24: 7213.

Journal article
Published: 18 March 2019 in Energy Procedia
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The use of energy efficient technologies for dehydration of food materials without compromising final food product quality is gaining increased interest in the food industry. A promising dehydration-enhancing process step that has been applied in the food industry mainly for pasteurisation operations is Ohmic heating. This study investigated the use of Ohmic and conventional thermal heating for dewatering of two citrus products, orange and grapefruit. A number of analyses including electrical thermal conductivity (ETC), energy consumption, cost, greenhouse gas (GHG) emissions, moisture content, PH and Vitamin C levels were performed. The results revealed that there was a positive increase of the ETC over time in both samples, resulting in higher values of 700C for the orange samples and 1000C for the grapefruit samples. The moisture content of the samples was significantly (P<0.05) reduced during Ohmic and thermal dehydration over time while no significant difference was detected in terms of pH and Vitamin C level. The analysis of energy consumption showed that thermal dehydration was between 3.5 and 5 times higher than Ohmic dehydration. Similar trend was observed in terms of cost and GHG emissions.

ACS Style

Valentina Stojceska; James Atuonwu; Savvas A Tassou. Ohmic and conventional drying of citrus products: energy efficiency, greenhouse gas emissions and nutritional properties. Energy Procedia 2019, 161, 165 -173.

AMA Style

Valentina Stojceska, James Atuonwu, Savvas A Tassou. Ohmic and conventional drying of citrus products: energy efficiency, greenhouse gas emissions and nutritional properties. Energy Procedia. 2019; 161 ():165-173.

Chicago/Turabian Style

Valentina Stojceska; James Atuonwu; Savvas A Tassou. 2019. "Ohmic and conventional drying of citrus products: energy efficiency, greenhouse gas emissions and nutritional properties." Energy Procedia 161, no. : 165-173.

Journal article
Published: 18 March 2019 in Energy Procedia
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In recent times, there has been a rise in interest on the applications of electro-technology based food processing methods. With drying in food industries being an energy intensive process with huge environmental impacts, the objective of this study was to design and develop a purpose-built laboratory system, for experimentally characterising an energy efficient electro-osmosis dewatering system. Electro-osmosis is a unique dewatering technique in which, moisture in food materials are removed by the application of low electric field (5-30 V). Different food materials namely, yogurt, orange pulp and egg whites were tested using electro-osmosis at 15 V and 30 V over 15 min and 30 min, respectively. The energy consumption (kWh), carbon footprint (kgCO2e) and cost indices (£/kg dried food) were also evaluated and compared with thermal drying.

ACS Style

Abhay Menon; Tonderai Reuben Mashyamombe; Erdogan Kaygen; Mina Sadat Mortazavi Nasiri; Valentina Stojceska. Electro-osmosis dewatering as an energy efficient technique for drying food materials. Energy Procedia 2019, 161, 123 -132.

AMA Style

Abhay Menon, Tonderai Reuben Mashyamombe, Erdogan Kaygen, Mina Sadat Mortazavi Nasiri, Valentina Stojceska. Electro-osmosis dewatering as an energy efficient technique for drying food materials. Energy Procedia. 2019; 161 ():123-132.

Chicago/Turabian Style

Abhay Menon; Tonderai Reuben Mashyamombe; Erdogan Kaygen; Mina Sadat Mortazavi Nasiri; Valentina Stojceska. 2019. "Electro-osmosis dewatering as an energy efficient technique for drying food materials." Energy Procedia 161, no. : 123-132.

Review
Published: 06 October 2015 in Journal of the International Society of Sports Nutrition
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Iron is a functional component of oxygen transport and energy production in humans and therefore is a critically important micronutrient for sport and exercise performance. Athletes, particularly female athletes participating in endurance sport, are at increased risk of compromised iron status due to heightened iron losses through menstruation and exercise-induced mechanisms associated with endurance activity. Conventionally oral iron supplementation is used in prevention or/and treatment of iron deficiency. However, this approach has been criticised because of the side effects and increased risk of iron toxicity associated with the use of supplements. Thus, more recently there has been a growing interest in using dietary modification rather than the use of supplements to improve iron status of athletes. Dietary iron treatment methods include the prescription of an iron-rich diet, or/and haem iron-based diet, dietary advice counselling and inclusion of novel iron-rich products into the daily diet. Although studies using dietary modification are still scarce, current literature suggests that dietary iron interventions can assist in maintaining iron status in female athletes, especially during intensive training and competition. Future research should focus on the most efficient method(s) of dietary modification for improvement of iron status and whether these approaches can have a favourable impact on sports and exercise performance.

ACS Style

Ieva Alaunyte; Valentina Stojceska; Andrew Plunkett. Iron and the female athlete: a review of dietary treatment methods for improving iron status and exercise performance. Journal of the International Society of Sports Nutrition 2015, 12, 1 -7.

AMA Style

Ieva Alaunyte, Valentina Stojceska, Andrew Plunkett. Iron and the female athlete: a review of dietary treatment methods for improving iron status and exercise performance. Journal of the International Society of Sports Nutrition. 2015; 12 (1):1-7.

Chicago/Turabian Style

Ieva Alaunyte; Valentina Stojceska; Andrew Plunkett. 2015. "Iron and the female athlete: a review of dietary treatment methods for improving iron status and exercise performance." Journal of the International Society of Sports Nutrition 12, no. 1: 1-7.

Journal article
Published: 01 June 2015 in Food Chemistry
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This study considers the use of dry Jerusalem artichoke (JA) as a functional nutrient in developing food products with enhanced nutritional characteristics and low glycaemic index (GI). Three different formulations based on buckwheat and JA were developed and processed using extrusion technology. Nutritional properties including the levels of total dietary fibre (TDF), protein, inulin, total carbohydrates and lipids were analysed. A clinical study was performed on ten healthy volunteers (aged between 21 and 56) to determine the level of GI and glycaemic load (GL). The results revealed that JA significantly (P<0.05) increased the levels of TDF and inulin whilst decreasing carbohydrates, lipids and proteins. The resulting products had a significant (P<0.05) effect on IAUC between reference food and extruded products, GI and GL. Samples containing 80% of Jerusalem artichoke were considered as a low GI food whilst samples containing 30% and 60% of Jerusalem artichoke as a medium GI food. A similar trend was seen in terms of GL.

ACS Style

Ana Radovanovic; Valentina Stojceska; Andrew Plunkett; Slobodan Jankovic; Dragan Milovanovic; Snezana Cupara. The use of dry Jerusalem artichoke as a functional nutrient in developing extruded food with low glycaemic index. Food Chemistry 2015, 177, 81 -88.

AMA Style

Ana Radovanovic, Valentina Stojceska, Andrew Plunkett, Slobodan Jankovic, Dragan Milovanovic, Snezana Cupara. The use of dry Jerusalem artichoke as a functional nutrient in developing extruded food with low glycaemic index. Food Chemistry. 2015; 177 ():81-88.

Chicago/Turabian Style

Ana Radovanovic; Valentina Stojceska; Andrew Plunkett; Slobodan Jankovic; Dragan Milovanovic; Snezana Cupara. 2015. "The use of dry Jerusalem artichoke as a functional nutrient in developing extruded food with low glycaemic index." Food Chemistry 177, no. : 81-88.

Journal article
Published: 18 October 2014 in Journal of the International Society of Sports Nutrition
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Adequate nutrient intake is critically important for achieving optimal sports performance. Like all athletes, female runners require a nutritionally balanced diet to maintain daily activities and a successful training regime. This study investigates the effects of cereal product based dietary iron intervention on iron status of recreational female runners (n=11; 32 ± 7yr; 239 ± 153 minutes exercise/week, of which 161 ± 150 minutes running activity/week; VO2max 38 ± 4 ml/kg/min). Participants completed a 6-week dietary intervention study. They were asked to replace their usual bread with iron-rich Teff bread as part of their daily diet. During this period, their dietary habits were assessed by multiple pass 24-hr recalls; iron status was determined by venous blood analysis for serum transferrin, serum transferrin receptor, serum ferritin, total iron-binding capacity and transferrin receptor/ferritin log index. Pre-intervention a cohort of 11 female runners reported inadequate daily dietary iron intake of 10.7 ± 2.7 mg/day, which was associated with overall compromised iron status. Over a third of all participants showed depleted bodily iron stores (serum ferritin < 12 μg/L). Pre-intervention macronutrient assessment revealed adequate energy, protein and fibre intakes, whilst total fat and saturated fat intake was above the recommendations at the expense of carbohydrate intake. A 6-week dietary intervention resulted in significantly higher total iron intakes (18.5 mg/day, P < 0.05) and improved iron tissue supply but not enlarged iron stores. Improvements in heamatological indices were associated with compromised baseline iron status, prolonged intervention period and increase in dietary iron intake. Dietary iron interventions using a staple cereal product offer an alternative way of improving dietary iron intake and favourable affecting overall iron status in physically active females.

ACS Style

Ieva Alaunyte; Valentina Stojceska; Andrew Plunkett; Emma Derbyshire. Dietary iron intervention using a staple food product for improvement of iron status in female runners. Journal of the International Society of Sports Nutrition 2014, 11, 1 -8.

AMA Style

Ieva Alaunyte, Valentina Stojceska, Andrew Plunkett, Emma Derbyshire. Dietary iron intervention using a staple food product for improvement of iron status in female runners. Journal of the International Society of Sports Nutrition. 2014; 11 (1):1-8.

Chicago/Turabian Style

Ieva Alaunyte; Valentina Stojceska; Andrew Plunkett; Emma Derbyshire. 2014. "Dietary iron intervention using a staple food product for improvement of iron status in female runners." Journal of the International Society of Sports Nutrition 11, no. 1: 1-8.

Journal article
Published: 26 July 2014 in Journal of Food Measurement and Characterization
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There is a growing demand for bread and other baked products that are gluten and wheat free due to the increased diagnosis and self-diagnosis of adverse reactions to wheat and gluten and an increase in the number of people who perceive a gluten or wheat free diet as a healthy lifestyle option. The removal of wheat from bread presents a number of technological challenges resulting in quality issues and nutrition. The increased consumer demand and growing industry response to these demands has meant that consumers will no longer accept compromise on taste or quality when purchasing gluten and wheat free bread. There is little information available that demonstrates customers’ expectations in terms of quality of gluten and wheat free breads. The aim of this research was to establish whether gluten and wheat free breads currently on the market are meeting consumer expectations and if not the key areas for product improvement and new product development. The research indicates that there are still significant improvements needed to produce gluten and wheat free bread that meets consumer expectations.

ACS Style

Ruth Potter; Valentina Stojceska; Andrew Plunkett. An investigation of the consumer perception on the quality of the gluten and wheat free breads available on the UK market. Journal of Food Measurement and Characterization 2014, 8, 362 -372.

AMA Style

Ruth Potter, Valentina Stojceska, Andrew Plunkett. An investigation of the consumer perception on the quality of the gluten and wheat free breads available on the UK market. Journal of Food Measurement and Characterization. 2014; 8 (4):362-372.

Chicago/Turabian Style

Ruth Potter; Valentina Stojceska; Andrew Plunkett. 2014. "An investigation of the consumer perception on the quality of the gluten and wheat free breads available on the UK market." Journal of Food Measurement and Characterization 8, no. 4: 362-372.