Papers by Valentina Stojceska
Journal of Human Nutrition and Dietetics, Jul 13, 2011
Background: Iron-deficiency anaemia is particularly prevalent in pregnancy. The present study aim... more Background: Iron-deficiency anaemia is particularly prevalent in pregnancy. The present study aimed to determine whether functional bread containing teff flour (i.e. naturally rich in iron) could be an alternative way of improving iron status. However, before testing whether its consumption can improve pregnancy iron status, the bio-availability of iron was determined in a sample of nonpregnant women. Methods: Fifty-eight women (20-50 years) were recruited from the University. Blood samples were taken at baseline to assess iron status and participants were screened to account for other factors affecting iron status. Twenty-four participants (haemoglobin 9.5-14.0 g dL)1) were recruited to take part in the intervention and allocated to five groups: (i) control bread (CB); (ii) teff bread (TB); (iii) TB + level 1 phytase (TB + P1); (iv) TB + level 2 phytase (TB + P2); or (v) a supplement containing 10 mg of ferrous sulphate. Venous blood samples were taken before the intervention and after 180-210 min, aiming to determine changes in serum iron. Results: Consuming three or four slices of TB provided statistically significantly more iron (7.6 mg) than CB (5.1 mg) (P < 0.001). Because participants were fasted, serum iron levels declined in all bread groups (average)1.5 lm), although the smallest reduction was observed in the TB + P2 group ()0.3 lm). The area-under-the-curve from baseline to 210 min was lower in the TB + P2 ()78.8 lmol min L)1) group compared to the other bread interventions, indicating higher levels of iron absorption in this group. Conclusions: The results obtained in the present study show that TB consumption may help to maintain serum iron levels, especially when phytase is added. The findings from the study also demonstrate there may be potential to further improve the bio-availability of iron from non-haem food sources.
Journal of Food Engineering, Dec 1, 2007
The rheological characteristics of twenty wheat flour samples obtained from four organic flour bl... more The rheological characteristics of twenty wheat flour samples obtained from four organic flour blends and a non-organic control were compared in relation to their ability to predict subsequent loaf volume in the baked bread. The flour samples considered had protein contents that varied between 11-14 g/100 g. Four different rheological methods were employed. Oscillatory stress rheometry on the protein gel extracted from the wheat flour, oscillatory stress rheometry and creep measurement on undeveloped dough samples and biaxial extensional measurements on simple flour-water doughs. None of the fundamental rheological parameters correlated with loaf volume. There was a correlation between the storage modulus of the gel protein and storage modulus for the undeveloped dough (r = 0.85). There was a weak negative correlation between protein content and biaxial extensional viscosity (r = À0.62). Stepwise multiple regression related loaf volume to dough stability time (measured on the Farinograph) and tan (phase angle) for the undeveloped dough samples (overall model r 2 = 0.54). The results indicate that the four rheological tests considered could not be used as predictors of subsequent loaf volume when the bread is baked.
Zenodo (CERN European Organization for Nuclear Research), Jul 13, 2023
The dairy industry is one of the growing sectors in the food industry with significant thermal en... more The dairy industry is one of the growing sectors in the food industry with significant thermal energy demand for their processes and temperature requirement of maximum 200 ℃. The use of solar energy for those process will reduce the fossil fuel dependency, greenhouse gas emission, environmental pollution and help to meet emission targets. Therefore, this study investigates the thermal requirements of a dairy company and provides a schematic of two integration concepts between the solar thermal energy system and their processes which are through the common energy supply line and inlets of individual processes. The study involves a case study that uses natural gas-powered boilers, and electrical powered chiller, ice banks and refrigerators to meet heating and cooling energy demand for the processes such as pasteurisation, fermentation and cold milk tanks. The overall energy consumption of the dairy processes is 1315 kWh at the full capacity operation, of which 1195 kWh can be theoretically replaced by the solar thermal energy. The temperature requirements of the processes are between 0 ℃ and 4 ℃ for cooling, and 170 ℃ for the heating. These thermal requirements can be met by using either parabolic trough or linear Fresnel solar thermal collectors along with thermal energy storage. The solar thermal energy integration concepts developed at supply level and process level use steam drum and absorption chiller to transfer the solar energy to the processes. The supply level integration has more advantages due to its easier control over the conventional and solar energy systems.
Zenodo (CERN European Organization for Nuclear Research), Jul 18, 2023
The environmental impact of a novel solar thermal technology called Sundial that uses rotary Fres... more The environmental impact of a novel solar thermal technology called Sundial that uses rotary Fresnel collectors is investigated. Two different designs were developed; one to be used for the metal processing industry located in a high latitude country and the other one for the dairy industry located in a low latitude country. In the metal processing industry, the Sundial replaces only the electricity while in the dairy industry, it replaces the use of fuel for heating and electricity for cooling. Environmental impact assessment of the Sundial units was conducted using SimaPro Software 9.2 and the results showed that the unit developed for the dairy industry had a higher environmental life cycle impact, which was related to the design of the unit containing more components and materials. A key advantage of the newly developed units is its ability to provide high temperatures for the requirements of the industrial processes like a metal processing industry. The carbon-dioxide emissions reductions for the potential application of the unit to the industrial process were also calculated for the both industries. It was projected that for the future capacity of the high latitude Sundial (HLS) of 1,828MWh, the GHG emissions reduction is 559.4 tonnes of CO2 emissions while the future capacity of the low latitude Sundial (LLS) of 2,158 MWh, the GHG emissions reduction is 909.6 tonnes of CO2 emissions. This demonstrates the great potential of the Sundial units to contribute to the decarbonization of industrial processes and meet the EU's 2050 environmental targets.
Thermal science and engineering progress, Feb 1, 2023
Elsevier eBooks, 2011
Publisher Summary BSG is a by-product from brewery and a cheap source of total dietary fiber that... more Publisher Summary BSG is a by-product from brewery and a cheap source of total dietary fiber that could be used as a functional ingredient in different food products. Dried Brewer's spent grain (BSG) has great potential to be used as a functional ingredient that may provide beneficial effects on human health. By incorporating BSG up to 30% in bread-making technology, the level of dietary fiber will increase up to fivefold. Loaf volume, texture, and shelf life of BSG can be improved by forming sourdough and using appropriate enzymes, such as Maxlife 85 (ME), Lipapan Extra (LE), Pentopan Mono (PE), and Celluclast (CL). LE in breads gave the most open network, increased wall thickness, and decreased cell density, which resulted in a higher loaf volume and extended shelf life. PE and Pentopan Mono and Celluclast (PCE) were more effective at increasing loaf volume and extending shelf life of breads containing higher amounts of fiber. However, the best results were obtained by a combination of sourdough with LE, PE, and ME, and PE with CL. Consuming a high level of dietary fiber food has been associated with the prevention of several diseases. Sensory characteristics and shelf life of BSG breads can be improved by adding enzymes and forming a sourdough.
Elsevier eBooks, 2019
Abstract This chapter deals with the potential application of brewer's spent grain (BSG) as a... more Abstract This chapter deals with the potential application of brewer's spent grain (BSG) as a functional ingredient in bread-making technology, to aid in the prevention of various diseases. The incorporation of BSG into bread-making technology improves the nutritional properties of its breads, resulting in increased levels of dietary fiber (DF), proteins, and phenolic compounds and effects on the textural and sensorial properties of BSG breads, including decreased level of loaf volume, increased level of water absorption, dough-development time, and dough stability. A number of methods have been reported as improving the textural and sensorial properties of BSG, including presoaking or fermentation before it is added to the dough, use of enzymes and dough conditioners, and forming sourdough. It has been scientifically proved that BSG plays a role in the prevention of certain diseases, including constipation, psychological function of colon, high cholesterol, and ulcerative colitis.
Zenodo (CERN European Organization for Nuclear Research), Jul 18, 2023
Version Issue Date % Complete * Changes Contributor(s) Any dissemination of results and any commu... more Version Issue Date % Complete * Changes Contributor(s) Any dissemination of results and any communication activity related to the action, reflects only the author's view and it does not necessarily represent the views expressed by the European Commission or its services. While the information contained in the documents is believed to be accurate, the authors(s) or any other participant in the ASTEP consortium make no warranty of any kind with regard to this material including, but not limited to the implied warranties of merchantability and fitness for a particular purpose.
Zenodo (CERN European Organization for Nuclear Research), Jul 18, 2023
Zenodo (CERN European Organization for Nuclear Research), Jul 18, 2023
This project has received funding from the European Union's Horizon 2020 research and innovation ... more This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 884411.
Zenodo (CERN European Organization for Nuclear Research), Oct 31, 2021
The report covers the first phase (M18 report) of the assessment of the potential environmental i... more The report covers the first phase (M18 report) of the assessment of the potential environmental impacts of ASTEP modular systems throughout the life cycle. It includes a literature review on the environmental impact of Concentrated Solar Power (CSP) plants and Environmental assessment of ASTEP systems.
Journal of Cereal Science, Nov 1, 2008
Twenty-four farinograms and accompanying flour characteristics obtained from a bakery were used t... more Twenty-four farinograms and accompanying flour characteristics obtained from a bakery were used to get additional information for baking characteristics of flours. Farinograms were digitized and four novel parameters were included for comparison: a and b were extracted from an equation of the form y ¼ ae Àbt ; the height of the upper curve and the width of the farinograph curve at a time value equal to the dough development time. Stepwise multiple regressions were carried out relating bread volume to novel and existing parameters (water absorption, development time, arrival time, departure time, stability and degree of softening). Results indicated that four farinogram parameters, resistance, water absorption, a and b were related to bake height with an overall value of 61%. A relatively weak correlation (R ¼ 0.44, P < 0.05) was detected between specific loaf volume and bake height.
Trends in Food Science and Technology, Mar 1, 2012
The objective of this study was to investigate the large variation in correlation coefficients re... more The objective of this study was to investigate the large variation in correlation coefficients reported in the literature for correlations between rheological properties of the wheat flour dough and its baking performance. While some studies reported in the literature on the correlations between dynamic rheological properties and baking performance that achieved high coefficient of correlation values, the studies appear to have limited ability to use dough rheological properties to predict baking performance. An analysis of a study with one of the highest values reported for the coefficient of correlation (r ¼ 0.94) between dynamic rheological properties and baking performance found that when the standard error for the correlation is considered, the value of the correlation for prediction purposes of loaf volume was extremely limited. It would appear that to develop models that could be used by the baking industry to predict wheat flour baking performance, many factors in addition to rheological parameters would have to be included in the model.
Sustainability, Dec 22, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Sustainability, Dec 16, 2019
High Concentrator Photovoltaic Thermal (HCPV/T) systems produce both electrical and thermal energ... more 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.
Elsevier eBooks, 2013
This chapter investigates the health benefits of whole grains in the production of ready-to-eat e... more This chapter investigates the health benefits of whole grains in the production of ready-to-eat expanded snacks. Extrusion technology is a popular and widely used continuous food processing technique that presents a great opportunity to produce ready-to-eat snacks with improved nutritional qualities. The incorporation of whole grains into expanded products has a beneficial effect in terms of dietary fibre, proteins, phytochemicals and vitamins, but it can also affect the physicochemical characteristics of the final product. Depending on the type of grain used, the product formulation and the extrusion conditions, considerable degradation could occur in terms of sensory appeal. Extrusion technology provides several ways in which these challenges can be overcome, by controlling extrusion conditions such as temperature, solid feed rate and screw speed combinations, and these will be discussed in this chapter.
Energy Procedia, Mar 1, 2019
District heating networks are commonly addressed in the literature as one of the most effective s... more District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, prolonging the investment return period. The main scope of this paper is to assess the feasibility of using the heat demand-outdoor temperature function for heat demand forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations.
Energy Procedia, Mar 1, 2019
District heating networks are commonly addressed in the literature as one of the most effective s... more District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, prolonging the investment return period. The main scope of this paper is to assess the feasibility of using the heat demand-outdoor temperature function for heat demand forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations.
Journal of Cleaner Production, 2018
This paper assesses the environmental profile of the biscuit supply chain for producing high qual... more This paper assesses the environmental profile of the biscuit supply chain for producing high quality gluten-free biscuits. Three different types of biscuits were considered. The assessment followed a cradleto-grave approach applying the ISO standards in compliance with the Product Category Rules (PCR) defined within EPD (Environmental Product Declaration) for bakery products. Analogous environmental profiles were implemented for assessing the products: It was found that the main hotspot in all impact categories was ingredients production with the range contribution from 22.2% to 84.9%, followed by transportation. Initial hypotheses for ingredients origin and waste management practices were demonstrated to have a key influence on the environmental results: higher packaging recycling rates and local ingredients usage led to improved environmental results (up to 5.5%) while direct food waste disposal was responsible for slightly unfavourable performance relative to base case (below 1%). Additionally, healthier ingredients such as xylitol and fructose were used to evaluate their potential benefits from an environmental perspective. It was found that only the use of fructose was a suitable alternative sweetener for more sustainable production.
Uploads
Papers by Valentina Stojceska