| 1. |
- Anker, M., et al.
(författare)
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Improved water vapor barrier of whey protein films by addition of an acetylated monoglyceride
- 2002
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Ingår i: Innovative Food Science & Emerging Technologies. - 1466-8564 .- 1878-5522. ; 3:1, s. 81-92
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to determine to what extent the water-vapor barrier of whey protein isolate (WPI) films could be improved by adding a lipid and make laminate and emulsion films. The laminate whey protein-lipid film decreased the water vapor permeability (WVP) 70 times compared with the WPI film. The WVP of the emulsion films was half the value of the WPI film and was not affected by changes in lipid concentration, whereas an increased homogenization led to a slight reduction in WVP. The mechanical properties showed that the lipid functioned as an apparent plasticizer by enhancing the fracture properties of the emulsion films. This effect increased with homogenization. The maximum strain at break was 117% compared with 50% for the less-homogenized emulsion films and 20% for the pure WPI films. Phase-separated emulsion films were produced with a concentration gradient of fat through the films, but pure bilayer films were not formed. © 2002 Elsevier Science Ltd. All rights reserved.
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| 2. |
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| 3. |
- Aronsson, Kristina, et al.
(författare)
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Inactivation of microorganisms using pulsed electric fields : The influence of process parameters on Escherichia coli, Listeria innocua, Leuconostoc mesenteroides and Saccharomyces cerevisiae
- 2001
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Ingår i: Innovative Food Science & Emerging Technologies. - 1466-8564 .- 1878-5522. ; 2:1, s. 41-54
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Tidskriftsartikel (refereegranskat)abstract
- This study examines the killing effect of pulsed electric fields (PEF) on four organisms suspended in a model medium. Escherichia coli, Listeria innocua, Leuconostoc mesenteroides and Saccharomyces cerevisiae differ in size, shape and cell wall construction. The electric field strength, pulse duration and number of pulses were varied in the ranges of 25-35 kV/cm, 2-4 ?s and 20-40 pulses, respectively. The results showed that S. cerevisiae was the most sensitive organism with a 6-log reduction, followed by E. coli with a 5.4-log reduction, when they were exposed to 30 kV/cm, and 20 pulses with 4 ?s duration. The most resistant organisms were L. innocua and L. mesenteroides with only a 3-log reduction, however, by increasing the parameters to 35 kV/cm and 40 pulses with 4 ?s pulse duration; marked viability reductions of 8 and 7 log, respectively, were observed. Heat, which is generated during the process, has limited killing effect on the cells, hence the observed reduction can be ascribed to the PEF treatment. Although transmission electron microscopy of PEF treated cells did not confirm membrane damage, observations suggest that PEF treatments have profound direct or indirect effects on the intracellular organisation of microorganisms. © 2001 Elsevier Science Ltd.
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| 4. |
- Aronsson, Kristina, et al.
(författare)
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Influence of pH, water activity and temperature on the inactivation of Escherichia coli and Saccharomyces cerevisiae by pulsed electric fields
- 2001
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Ingår i: Innovative Food Science & Emerging Technologies. - 1466-8564 .- 1878-5522. ; 2:2, s. 105-112
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to examine the influence of pH, water activity (aw) and temperature on the killing effect of pulsed electric fields (PEF). Escherichia coli and Saccharomyces cerevisiae suspended in a model media were subjected to 20 pulses with 4 ?s duration in a continuous PEF system, during which the effects of pH (4.0-7.0), aw (1.00-0.94) and inlet temperature (10°C and 30°C) could easily be studied. Electrical field strengths were set to 25 kV/cm for S. cerevisiae and 30 kV/cm for E. coli and the highest outlet temperature was monitored to 44°C. A synergy of low pH values, high temperatures and PEF processing was observed. A drop in pH value from 7.0 to 4.0 resulted in the reduction of E. coli by four additional log units, whereas for S. cerevisiae, the pH effect was less pronounced. Lowering aw seems to protect both E. coli and S. cerevisiae from PEF processing. © 2001 Elsevier Science Ltd.
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| 5. |
- Lindgren, M., et al.
(författare)
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Simulation of the temperature increase in pulsed electric field (PEF) continuous flow treatment chambers
- 2002
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Ingår i: Innovative Food Science & Emerging Technologies. - 1466-8564 .- 1878-5522. ; 3:3, s. 233-245
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Tidskriftsartikel (refereegranskat)abstract
- The application of intense pulsed electric fields (PEF) in foods is intended to be a non-thermal method to inactivate microorganisms. However, it is well known that an increase in temperature is present in this process due to ohmic heating, where the pulsed electric field energy input is transformed into heat. The aim of this study was to investigate the computer modeled temperature increase in the outflow for different flow-through PEF treatment chamber designs. Given equal experimental conditions, the temperature increase is indicative of the PEF dose, and a more uniform temperature profile is thus indicative of a more homogeneous PEF treatment. The radial distribution of the temperature increase was simulated in computer models of four different chambers. The temperature increase was found to be more homogeneous in the treatment chambers making use of a decrease in the insulator diameter, i.e. a design letting the insulators and electrodes intersect at angles close to 90°. The maximum temperature increase was found close to the wall, where the flow velocity is low. Cooling of the electrodes and electric insulators is recommended to avoid too high a temperature increase. The minimum temperature increase found was 29% of the calculated average in the worst case studied here. The minimum PEF dose to which the food was subjected would thus is less than the intended dose, since the food clearly was not subjected to the intended electric field strength during the intended exposure time. This is an important result in terms of food safety in the sense that a minimum PEF treatment should be guaranteed. The microbiological inactivation was experimentally evaluated using two of the treatment chamber designs. The result is consistent with the simulations and shows a small increase in inactivation and less needed energy input giving less average temperature increase for the chamber implementing a contraction of the diameter of the insulating spacer. © 2002 Elsevier Science Ltd. All rights reserved.
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| 6. |
- Vardakou, M., et al.
(författare)
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Synergy between enzymes involved in the degradation of insoluble wheat flour arabinoxylan
- 2004
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Ingår i: Innovative Food Science & Emerging Technologies. - 1466-8564 .- 1878-5522. ; 5:1, s. 107-112
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Tidskriftsartikel (refereegranskat)abstract
- Two microbial endo-β-1,4-xylanases (EXs, EC 3.2.1.8) belonging to glycanase families 10 and 11 were examined for their ability to release ferulic acid (FA) from water-unextractable arabinoxylan (WU-AX) in the presence of a feruloyl esterase (FoFAE-II) from Fusarium oxysporum. WU-AX was incubated with different levels of a Thermoascus aurantiacus family 10 (XYLI) and a Sporotrichum thermophile family 11 (XYLA) endoxylanases. At 10 g/l arabinoxylan, enzyme concentrations (KE values) needed to obtain half-maximal hydrolysis rates for FA release were 0.18 and 0.44 nM for the xylanases from T. aurantiacus and S. thermophile, respectively. Determination of Vmax/KE revealed that the family 10 enzyme performed 4.3 times more efficiently than the family 11 enzyme in liberation of FA when a feruloyl esterase is present. Molecular weights of the products formed were assessed and separation of feruloyl-oligosaccharides was achieved by anion-exchange and size-exclusion chromatography (SEC). The results showed that the degradation of the xylan backbone was influenced strongest by the action of xylanases while the presence of the esterase mainly resulted in the release of ferulic acid from the produced short chain feruloylated xylo-oligosaccharides by the action of xylanases
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| 7. |
- Al-Naamani, Laila, et al.
(författare)
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Chitosan-zinc oxide nanoparticle composite coating for active food packaging applications
- 2016
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Ingår i: Innovative Food Science & Emerging Technologies. - : Elsevier. - 1466-8564 .- 1878-5522. ; 38, s. 231-237
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Tidskriftsartikel (refereegranskat)abstract
- In this study antimicrobial properties of chitosan and chitosan-zinc oxide (ZnO) nanocomposite coatings on PE films were studied. Oxygen plasma pretreatment of PE films led to increased adhesion by 2% of chitosan and the nanocomposite coating solutions to the packaging films. Scanning Electron Microscopy (SEM) revealed uniform coatings on PE surfaces. Incorporation of ZnO nanoparticles into the chitosan matrix resulted in 42% increase in solubility; swelling decreased by 80% while the water contact angle (WCA) increased from 60 to 95 compared to chitosan coating. PE coated with chitosan-ZnO nanocomposite films completely inactivated and prevented the growth of food pathogens, while chitosan-coated films showed only 10-fold decline in the viable cell counts of Salmonella enterica, Escherichia coli and Staphylococcus aureus after 24-h incubation compared to the control. Industrial relevance: One of the greatest challenges of food industry is microbial contamination. The present study suggests that PE coating with chitosan-ZnO nanocomposite is a promising technique to enhance antimicrobial properties of the films. Chitosan-ZnO nanocomposite coatings improved antibacterial properties of PE by inactivating about 99.9% of viable pathogenic bacteria. Hence, our results show the effectiveness of the nanocomposite coating in the development of active food packaging in order to prolong the shelf life of food products.
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| 8. |
- Ceresino, Elaine Berger, et al.
(författare)
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Processing conditions and transglutaminase sources to "drive" the wheat gluten dough quality
- 2020
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Ingår i: Innovative Food Science & Emerging Technologies. - : Elsevier BV. - 1466-8564 .- 1878-5522. ; 65
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Tidskriftsartikel (refereegranskat)abstract
- Gluten proteins are highly impacting the quality of various gluten-based products, and transglutaminases (TGs) are used to influence the protein cross-linking. In this study we monitored the interplay of "harsh" and "mild" gluten processing for dough mixing and pasta-like sheet production and TGs from a commercial and newly sourced bacteria (SB6). Despite the harshly separated gluten presenting strongly cross-linked proteins in the beginning of the mixing, similar levels of polymerization were achieved at the optimum mixing time but with differences in the secondary protein structure. TG addition increased polymerization in wheat doughs, possibly as a result of increased glutenin polymerization, while gliadins become more soluble with SB6. This enzyme also dramatically increased polymerization in mild gluten. These results show that an adequate investigation when using TGs and gluten from various origins is necessary to adequately predict the quality in various gluten-based products, thus, of great relevance to the food industry. Industrial relevance: Currently, there is a mounting trend towards the modification of gluten proteins to improve technological features and functionality. In breadmaking, when weak Hour (low protein content) is used or general stabilization is desired for technological purposes, additives can be used to stabilize the gluten protein matrix. The use of transglutaminase (TG) has grown in popularity as they promote specific cross-linking between residues of glutamine and lysine in proteins. Another way of improving dough functionality is by increasing the oxidation of disulfide groups by adding gluten which is a co-product of the starch industry. Industrial production of gluten includes the use of heating and shear forces, which may impact gluten dough-forming ability. Thus, increased understanding of the interplay of gluten processing and the impact of choice of the TG origin in gluten dough quality is highly applicable in food industry.
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| 9. |
- Flynn, Katherine M., et al.
(författare)
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Ideal skills for European food scientists and technologists : Identifying the most desired knowledge, skills and competencies
- 2013
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Ingår i: Innovative Food Science & Emerging Technologies. - : Elsevier BV. - 1466-8564 .- 1878-5522. ; 18, s. 246-255
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Tidskriftsartikel (refereegranskat)abstract
- Training food scientists and technologists (FSTs) to have appropriate skills begins with identification of those skills most desired by employers. Between March 2010 and August 2011, 16 workshops in 16 countries had 315 local FST employers contribute ideas of skills desired in their FSTs. Attendees provided as many skills as possible and these descriptive data were quantifed and then analysed with multiple contingency tables and chi squared testing. Of the 3348 skill ideas provided, the most desired skill overall was Communicating, which was identified 13% of the time. Separate analysis of the 792 food sector skills indicated Product Development, at 28%, as the most desired. Geographical region, employment area and FST level of responsibility all significantly influenced the top 3 choices of overall skills and of food sector skills, indicating that most desired skills in the food industry are not uniform. These results should contribute to the improvement of FST training and thus benefit the European food industry. Industrial relevance: The data presented here suggest that improvements in FST training, particularly the acquisition of 'soft skills', will improve Europe's food workforce as these are the skills employers most desire. These data further suggest that geographical region significantly influences those skills most desired by industrial employers. Differences in desired skills at different levels of FST responsibility further suggest that continual FST training i.e., continual professional development, will contribute to improved FST performance. Overall, this study presents data which can improve FST performance and thus contribute to increased innovation and competitiveness of the food and drink industry.
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| 10. |
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