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A new approach to the creation of polypropylene (PP) based foaming materials was developed using food grade foaming agents that were coated on the PP pellets. More specifically, sodium bicarbonate and organic acids were used to coat PP pellets using either polyethyleneoxide (PEO) or lipid esters as coating stabilizers. In order to overcome the problem of the thermal decomposition of sodium bicarbonate at temperatures lower than the PP melting temperature, which makes the direct foaming during melt mixing impossible, the proposed methodology was proved quite efficient. Thus, new PP masterbatches were prepared, where the foaming agents were incorporated as coating at PP pellets at contents up to 10%, and initially used in Lab scale injection machines in order to find the best combination of materials that resulted in the production of foamed articles. Subsequently selected material combinations were tested in an industrial scale injection molding machine, where an optimization of the injection parameters was attempted. The outcome of this was the production of PP articles with significantly increased void fraction, up to 14%, decreased thermal conductivity, up to 20%, and various pore sizes as was observed via microscopic examination using SEM and CLSM.
Artemis Tsagdi; Ioannis Drossos; Despoina Georgiou; Stylianos Exarhopoulos; Georgios Karasiotas; Joannis Kallitsis; Eleni Kalogianni. Injection Molded PP Foams Using Food Ingredients for Food Packaging Applications. Polymers 2021, 13, 288 .
AMA StyleArtemis Tsagdi, Ioannis Drossos, Despoina Georgiou, Stylianos Exarhopoulos, Georgios Karasiotas, Joannis Kallitsis, Eleni Kalogianni. Injection Molded PP Foams Using Food Ingredients for Food Packaging Applications. Polymers. 2021; 13 (2):288.
Chicago/Turabian StyleArtemis Tsagdi; Ioannis Drossos; Despoina Georgiou; Stylianos Exarhopoulos; Georgios Karasiotas; Joannis Kallitsis; Eleni Kalogianni. 2021. "Injection Molded PP Foams Using Food Ingredients for Food Packaging Applications." Polymers 13, no. 2: 288.
Partial (one month) composting of solid olive processing waste is shown to produce extractable emulsifiers. Size exclusion chromatography (SEC) and Fourier-transform infra-red spectroscopy (FTIR) show that these consist of polysaccharides and proteins from the composted waste. Aqueous extraction at pH 5, pH 7, and pH 9 all yield extracts rich in oligosacchrides and oligopeptides which derive from the break-down of the macromolecules under composting, with the extract obtained at pH 5 being the richer in such components. Fourier-transform infra-red (FTIR) spectroscopy also confirms that these materials consist of proteinic and poly/oligosaccharidic populations. These materials can emulsify stable oil-in-water emulsions at pH 3 for a few days, while the same emulsions collapse in less than 24 h at pH 7. Confocal microscopy and droplet size distribution data suggest that Ostwald ripening, rather than coalescence, is the major course of emulsion instability. The above point to a short-process alternative to full composting in producing a high added value product from solid olive processing waste.
Aikaterini Koliastasi; Vasiliki Kompothekra; Charilaos Giotis; Antonis K. Moustakas; Efstathia P. Skotti; Argyrios Gerakis; Eleni P. Kalogianni; Christos Ritzoulis. Emulsifiers from Partially Composted Olive Waste. Foods 2019, 8, 271 .
AMA StyleAikaterini Koliastasi, Vasiliki Kompothekra, Charilaos Giotis, Antonis K. Moustakas, Efstathia P. Skotti, Argyrios Gerakis, Eleni P. Kalogianni, Christos Ritzoulis. Emulsifiers from Partially Composted Olive Waste. Foods. 2019; 8 (7):271.
Chicago/Turabian StyleAikaterini Koliastasi; Vasiliki Kompothekra; Charilaos Giotis; Antonis K. Moustakas; Efstathia P. Skotti; Argyrios Gerakis; Eleni P. Kalogianni; Christos Ritzoulis. 2019. "Emulsifiers from Partially Composted Olive Waste." Foods 8, no. 7: 271.
The objective of this research was to perform an exposure assessment of aflatoxin M1 (AFM1) intake through the consumption of milk and yoghurt by the student population in Serbia and Greece. A food consumption survey of milk and yoghurt was performed during the first half of 2018 in the two countries with at least 500 interviewees (aged between 18 and 27 years) per country, covering their dietary habits and body weight based on one-day and seven-day recall methods. Values for the concentration of AFM1 were extracted from published research. Finally, a Monte Carlo analysis of 100,000 iterations was performed to estimate the intake of AFM1 from the consumption of the two dairy products. Results revealed that the estimated average exposure of students to AFM1 was in the range of 1.238–2.674 ng kg−1 bw day−1 for Serbia, and 0.350–0.499 ng kg−1 bw day−1 for Greece, depending on the dietary recall method employed. High estimations for hepatocellular carcinoma (HCC) cases/year/105 individuals, depending on the prevalence of Hepatitis B virus surface antigen positive individuals (HBsAg+), were 0.0036–0.0047 and 0.0007–0.0009 for Serbia and Greece, respectively. Presented Margin of Exposure (MOE) and Hazard Index (HI) values indicate increased risk from exposure to AFM1, particularly in Serbia.
Bozidar Udovicki; Ilija Djekic; Eleni P. Kalogianni; Andreja Rajkovic. Exposure Assessment and Risk Characterization of Aflatoxin M1 Intake through Consumption of Milk and Yoghurt by Student Population in Serbia and Greece. Toxins 2019, 11, 205 .
AMA StyleBozidar Udovicki, Ilija Djekic, Eleni P. Kalogianni, Andreja Rajkovic. Exposure Assessment and Risk Characterization of Aflatoxin M1 Intake through Consumption of Milk and Yoghurt by Student Population in Serbia and Greece. Toxins. 2019; 11 (4):205.
Chicago/Turabian StyleBozidar Udovicki; Ilija Djekic; Eleni P. Kalogianni; Andreja Rajkovic. 2019. "Exposure Assessment and Risk Characterization of Aflatoxin M1 Intake through Consumption of Milk and Yoghurt by Student Population in Serbia and Greece." Toxins 11, no. 4: 205.
Coalescence of olive oil droplets during malaxation is a crucial phenomenon since it is responsible for the effective oil separation in the following processing steps. Yet it has been scarcely examined. The aim of this work was to study in detail the evolution of droplet size distribution during malaxation in actual processing conditions. For that reason experiments took place in an industrial scale olive oil extraction plant. The effect of malaxation time and the effect of water dilution on the droplet size distribution were examined. The results depict the progressive olive oil droplet coalescence and show a clear effect of water dilution on the rate of coalescence. The higher coalescence rate in the diluted paste was attributed to the decrease in viscosity. Finally it was shown that separation of the diluted paste in a two-phase decanter resulted into smaller droplet sizes (and therefore lower oil content) remaining in the paste.
Eleni P. Kalogianni; Despoina Georgiou; Stylianos Exarhopoulos. Olive oil droplet coalescence during malaxation. Journal of Food Engineering 2018, 240, 99 -104.
AMA StyleEleni P. Kalogianni, Despoina Georgiou, Stylianos Exarhopoulos. Olive oil droplet coalescence during malaxation. Journal of Food Engineering. 2018; 240 ():99-104.
Chicago/Turabian StyleEleni P. Kalogianni; Despoina Georgiou; Stylianos Exarhopoulos. 2018. "Olive oil droplet coalescence during malaxation." Journal of Food Engineering 240, no. : 99-104.
Capillary penetration is commonly used in a wide range of applications such as oil recovery, textile engineering and food technology. Furthermore, it is a useful tool for surface characterization of powders and porous media. Two are the commonest experimental methods to study capillary penetration: the height-time and the weight-time technique. However, it is not clear whether the two approaches provide the same results. This work aims to investigate similarities and differences between the two approaches and assess whether it is possible to replace one with another. To this end, capillary penetration experiments were performed in different porous media where the pore size distribution and shape varied. Height and weight data were recorded simultaneously. It was found that results of the two experimental approaches are not always equivalent and that this depends on the porous medium properties. In some cases results depended on the degree of saturation of the porous medium with the penetrating liquid. An analysis of weight-time data to provide pore size distribution as a function of pore volume is proposed. Furthermore, two different approaches of the fractal theory were applied and the time exponent, the material fractal dimension and the tortuosity fractal dimension were determined.
Despoina Geogiou; Eleni P. Kalogianni. Height–time and weight–time approach in capillary penetration: Investigation of similarities and differences. Journal of Colloid and Interface Science 2017, 495, 149 -156.
AMA StyleDespoina Geogiou, Eleni P. Kalogianni. Height–time and weight–time approach in capillary penetration: Investigation of similarities and differences. Journal of Colloid and Interface Science. 2017; 495 ():149-156.
Chicago/Turabian StyleDespoina Geogiou; Eleni P. Kalogianni. 2017. "Height–time and weight–time approach in capillary penetration: Investigation of similarities and differences." Journal of Colloid and Interface Science 495, no. : 149-156.
This work focuses on the evaluation of commercially available rapid methods for determining frying oil quality. Five rapid methods differing in principle were selected: FOM320 (Ebro), PCT120 (3M), LRSM (3M), Fritest (Merck) and Viscofrit (Viscofrit). The performance of the methods was examined by use of 184 oil samples produced by controlled frying experiments. Twelve series of frying experiments (45 batches each) were performed in which the oil type (palm, sunflower and olive) and the food type (potatoes, zucchini and minced beef meat) varied. Control thermal oxidation experiments with the same oil types were also performed. Results of the rapid methods were compared to results of analytical methods determining legislation criteria. Namely, the total polar compounds and total polymer compounds were determined using High Pressure Size Exclusion Chromatography with and without prior separation of the polar fraction. Furthermore, determination of the free fatty acid concentration, acidity, viscosity and level of oxidation of the oils using UV spectroscopy were carried out. Principal component analysis and linear regression analysis were used in order to assess the obtained results. Comparison of the results of the rapid methods with the analytical ones showed differences in most examined cases. For many of the examined rapid methods the agreement of the results versus those of analytical methods depended on the food-oil combination used in the frying experiments.
Eleni P. Kalogianni; Despoina Georgiou; Maria Romaidi; Stylianos Exarhopoulos; Dimitris Petridis; Calliope Karastogiannidou; Georgia Dimitreli; Paraskevi Karakosta. Rapid Methods for Frying Oil Quality Determination: Evaluation with Respect to Legislation Criteria. Journal of the American Oil Chemists' Society 2016, 94, 19 -36.
AMA StyleEleni P. Kalogianni, Despoina Georgiou, Maria Romaidi, Stylianos Exarhopoulos, Dimitris Petridis, Calliope Karastogiannidou, Georgia Dimitreli, Paraskevi Karakosta. Rapid Methods for Frying Oil Quality Determination: Evaluation with Respect to Legislation Criteria. Journal of the American Oil Chemists' Society. 2016; 94 (1):19-36.
Chicago/Turabian StyleEleni P. Kalogianni; Despoina Georgiou; Maria Romaidi; Stylianos Exarhopoulos; Dimitris Petridis; Calliope Karastogiannidou; Georgia Dimitreli; Paraskevi Karakosta. 2016. "Rapid Methods for Frying Oil Quality Determination: Evaluation with Respect to Legislation Criteria." Journal of the American Oil Chemists' Society 94, no. 1: 19-36.