| 1. |
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| 2. |
- Wendin, Karin, 1963-, et al.
(författare)
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Dynamic analyses of sensory and microstructural properties of cream cheese
- 2000
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Ingår i: Food Chemistry. - 0308-8146 .- 1873-7072. ; 71:3, s. 363-378
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Tidskriftsartikel (refereegranskat)abstract
- Flavour and texture in cream cheese depend on the microstructure. The objective of this work was to study the influence of fat content, salt content and homogenisation pressure on the microstructure and sensory properties of cream cheese. Twelve types of cream cheese were produced according to a full-factorial design, whereby the fat content was set at three levels, the salt content at two levels and the homogenisation pressure at two levels. The cheeses were analysed by a sensory panel, using both quantitative descriptive profiling and time intensity (T1) evaluation, and by using a confocal laser scanning microscope, CLSM, whereby the microstructure of the cheeses was analysed. All the design parameters had a significant influence on the flavour and texture, although fat had the largest effect. Interaction effects between the design parameters were also found to influence the character of cream cheese. The results showed that it is possible to create a cream cheese with lower fat content and with sensory attributes similar to the attributes in cream cheese with high fat content, by modification of production parameters.
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| 3. |
- Viklund, Gunilla, et al.
(författare)
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Acrylamide in crisps: Effect of blanching studied on long-term stored potato clones
- 2010
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Ingår i: Journal of Food Composition and Analysis. - : Elsevier BV. - 0889-1575 .- 1096-0481. ; 23:2, s. 194-198
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Tidskriftsartikel (refereegranskat)abstract
- Acrylamide, a probable carcinogen, is formed via the Maillard reaction between reducing sugars and the amino acid asparagine during heating of carbohydrate-rich foods. Potatoes contain high levels of these precursors, and thus potato crisps can contain high levels of acrylamide. In this study, the effect of blanching on the concentration of precursors and acrylamide content was studied in three potato clones stored at 4 degrees C or 8 degrees C. After 6, 12 and 18 weeks of storage, potatoes were sliced and blanched for 3 min in water at 80 degrees C and deep-fat fried for 3 min at an initial frying temperature of 180 degrees C and a final frying temperature of 160 degrees C. Blanching reduced the acrylamide content by 51-73%. Interestingly, blanching affected the levels of the precursor sugars and asparagine, but not the acrylamide content to the same extent. The reduction of precursors was 17-66%. This may be due to restriction of the transport of precursors to the surface, as the availability of precursors for reactions is crucial for acrylamide formation. In conclusion, blanching was an efficient way to reduce acrylamide content in potato crisps, in addition to using potatoes low in asparagine and reducing sugars. (C) 2009 Elsevier Inc. All rights reserved.
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| 4. |
- Skoglund, Tomas
(författare)
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Dynamic Modelling and Simulation of Liquid Food Process Lines
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the present work a dynamic model library of components for process lines was developed. The analysis addressed characteristic aspects of liquid food process lines, and new models were developed for fluid transitions, dispersion, mixing zones and first-order chemical reactions in pipes and heat exchangers. The computational efficiency and accuracy of the models were analysed. It was demonstrated that classical models of fluid propagation in process lines could be combined with modern numerical methods to obtain computationally efficient dynamic models for the simulation of dispersed convective flow, with and without chemical reactions. In particular it was demonstrated that a transport delay model was well suited for the simulation of thermal transients due to fluid transitions in heat exchangers. It was shown that the model could be extended to account for dispersion with a method that, although classical in approach, enables a certain freedom in the choice of degree of discretization depending on the demand for accuracy vs. computational speed. Further extension of the model with first-order chemical reactions to account for microbial deactivation was demonstrated. The usefulness of the dispersed-convection model to predict the extent of mixing zones and the amount of product rejects in continuous processing was demonstrated. The relevance concerning product traceability is discussed and the concept ?fuzzy traceability? introduced.
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| 5. |
- Song, Xiao, et al.
(författare)
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Food desires and hedonic discrimination in virtual reality varying in product–context appropriateness among older consumers
- 2022
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Ingår i: Foods. - : MDPI. - 2304-8158. ; 11:20
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Tidskriftsartikel (refereegranskat)abstract
- Immersive virtual reality (VR) videos can replicate complex real-life situations in a systematic, repeatable and versatile manner. New product development trajectories should consider the complexities of daily life eating situations. The creation of immersive contexts of a product with varying levels of appropriateness could be a useful tool for product developers in evaluating the extent to which context may influence food acceptance and eating behavior. This study explored virtual reality (VR) as an efficient context-enhancing technology through evaluations of protein-enriched rye breads and compared the effects of a VR-simulated congruent (VR restaurant) and incongruent (VR cinema) contexts on the acceptance in older consumers. A total of 70 participants were immersed in the two VR contexts and a neutral control context in a randomized order. The responses indicating the desire and liking for rye breads were measured, and the extent of immersion during context exposure was assessed by levels of the sense of presence and engagement. Immersive VR induced positive sensations of presence and a heightened level of engagement. The VR restaurant and neutral contexts were perceived as more appropriate for consuming rye breads and induced higher desire and liking for rye breads, which supported the notion of the alignment of congruent contexts with food desire and liking. The study provides new perspectives, practical methodologies, and discoveries in regard to the creation and application of VR-immersed contexts in food product evaluation. Moreover, it focused on a consumer segment (older consumers) that has seldom been investigated in previous relevant studies. The findings suggest that immersive VR technology, as a tool for evaluating contextual factors, is important for new product development. The good user experience among older consumers further indicated the potential value of VR as a context-enhancing tool for product development.
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| 6. |
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| 7. |
- Trigo, João Pedro, 1995, et al.
(författare)
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Mild blanching prior to pH-shift processing of Saccharina latissima retains protein extraction yields and amino acid levels of extracts while minimizing iodine content
- 2023
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 404
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Tidskriftsartikel (refereegranskat)abstract
- The seaweed Saccharina latissima is often blanched to lower iodine levels, however, it is not known how blanching affects protein extraction. We assessed the effect of blanching or soaking (80/45/12 °C, 2 min) on protein yield and protein extract characteristics after pH-shift processing of S. latissima. Average protein yields and extract amino acid levels ranked treatments as follows: blanching-45 °C ∼ control > soaking ∼ blanching-80 °C. Although blanching-45 °C decreased protein solubilization yield at pH 12, it increased isoelectric protein precipitation yield at pH 2 (p < 0.05). The former could be explained by a higher ratio of large peptides/proteins in the blanched biomass as shown by HP-SEC, whereas the latter by blanching-induced lowering of ionic strength, as verified by a dialysis model. Moreover, blanching-45 °C yielded a protein extract with 49 % less iodine compared with the control extract. We recommend blanching-45 °C since it is effective at removing iodine and does not compromise total protein extraction yield.
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| 8. |
- Lindborg, PerMagnus, 1968-
(författare)
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A taxonomy of sound sources in restaurants
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Ingår i: Applied Acoustics. - 0003-682X .- 1872-910X.
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Tidskriftsartikel (refereegranskat)abstract
- Restaurants are complex environments where all our senses are engaged. Physical and psychoacoustic factors have been shown to be associated with perceived environmental quality in restaurants. More or less designable sound sources such as background music, voices, and kitchen noises are believed to be important in relation to the overall perception of the soundscape. Previous research publications have suggested typologies and other structured descriptions of sound sources for some environmental contexts, such as urban parks and offices, but there is no detailed account that is relevant to restaurants. While existing classification schemes might be extendable, an empirical approach was taken in the present work. We collected on-site data in 40 restaurants (n = 393), including perceptual ratings, free-form annotations of characteristic sounds and whether they were liked or not, and free-form descriptive words for the environment as a whole. The annotations were subjected to analysis using a cladistic approach and yielded a multi-level taxonomy of perceived sound sources in restaurants. Ten different classification taxa were evaluated by comparing the respondents' Liking of sound sources, by categories defined in the taxonomy, and their Pleasantness rating of the environment as a whole. Correlation analysis revealed that a four-level clade was efficient and outperformed alternatives. Internal validation of the Pleasantness construct was made through separate ratings (n = 7) of on-site free-form descriptions of the environment. External validation was made with ratings from a separate listening experiment (n = 48). The two validations demonstrated that the four-level Sound Sources in Restaurants (SSR) clade had good construct validity and external robustness. Analysis of the data revealed two findings. Voice-related characteristic sounds including a ‘people’ specifier were more liked than those without such a specifier (d = 0.14 SD), possibly due to an emotional crossmodal association mechanism. Liking of characteristic sounds differed between the first and last annotations that the respondents had made (d = 0.21 SD), which might be due to an initially positive bias being countered by exposure to a task inducing a mode of critical listening. We believe that the SSR taxonomy will be useful for field research and simulation design. The empirical findings might inform theory, specifically research charting the perception of sound sources in multimodal environments.
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| 9. |
- Williams, Helén, et al.
(författare)
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Consumer Perceptions of Food Packaging : Contributing to or Counteracting Envir onmentally Sustainable Development?
- 2016
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Ingår i: Packaging technology & science. - : John Wiley & Sons. - 0894-3214 .- 1099-1522. ; 29:1, s. 3-23
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Tidskriftsartikel (refereegranskat)abstract
- Packaging has a fundamental role in ensuring safe delivery of goods throughout supply chains to the end consumer in good condition. It also has great potential to contribute to sustainable development. This paper explores and provides insights on Swedish consumer perceptions and knowledge of environmental aspects of food packaging and elaborates on how these can contribute to or counteract environmentally sustainable development. A study based on a consumer survey carried out in Sweden is presented. A review of recent packaging research emphasizes the protective function of packaging as its most important contribution to the environmental dimension of sustainable development. Contrary to this, consumers almost exclusively refer to the packaging material when it comes to their perceptions of the environmental impact of packaging. Paper-based packaging is strongly understood by the surveyed consumers to be environmentally advantageous, whereas plastic and metal are not. This study further indicates that a majority of the Swedish consumers surveyed are aware of their shortcomings in judging the environmental status of food packaging, indicating a need for guidance; otherwise, consumer choices can unintendedly counteract environmentally sustainable intentions
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| 10. |
- Månsson, Tommie, 1987
(författare)
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Supermarket refrigeration systems for demand response in smart grids
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- With an increasing share of intermittent renewable energy sources in the electrical grid, the need for adapting the demand to the available supply of electricity becomes increasingly important. Within this thesis, the demand response capacity by supermarket refrigeration systems are investigated and methods for enabling it is developed. Article 1 explores the temperature control system in depth, concluding that the majority (80.5 %) of return air temperature sensors in RDCs were located in an area where a thermal gradient interfere with the perceived temperature, i.e. the temperature readings falsely indicated a higher return air temperature than the actual mean temperature of the passing air. The issue is analysed in detail and mitigated through a strategic re-positioning of the affected temperature sensors. Article 2 presents a computationally efficient yet accurate dynamic hygro-thermal model of an RDC with the capability to include effects of door openings. Thus, the model contributes to enabling demand response by supermarkets as it could provide the forecasts of the necessary temperature constraints, limiting the duration for which the supermarket could attend to a demand response request. Article 3 presents a field study where wireless gyroscopes were attached to the RDC doors in an operational supermarket to record the speed, duration, angle and frequency that the doors are operated at. Novel insights in significant differences in behaviour between medium and low temperature RDCs could be concluded. Article 4 presents a method for the thermal characterisation of RDCs based on an adaption of the Co-Heating methodology. The method evaluates infiltration rates within the 10 % limit compared with the condensate collection method. In addition, data on thermal performance, such as the heat transfer coefficient for the envelope and its thermal inertia, can be measured in a systematic way. The thesis together with the four appended articles presents a suite for the evaluation of temperature development in refrigerated display cabinets in operational supermarkets, which represents the main constrain for the demand response capacity.
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| 11. |
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| 12. |
- Pietiäinen, Solja, et al.
(författare)
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Effect of physicochemical properties, pre-processing, and extraction on the functionality of wheat bran arabinoxylans in breadmaking – A review
- 2022
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 383
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Forskningsöversikt (refereegranskat)abstract
- Arabinoxylan (AX) is an abundant hemicellulose in wheat bran and an important functional component in bakery products. This review compares preprocessing and extraction methods, and evaluates their effect on AX properties and functionality as a bread ingredient. The extraction process results in AX isolates or concentrates with varying molecular characteristics, indicating that the process can be adjusted to produce AX with targeted functionality. AX functionality in bread seems to depend on AX properties but also on AX addition level and interactions with other components. This review suggests that the use of AX with tailored properties together with properly optimized baking process could help increasing the amount of added fiber in bread while maintaining or even improving bread quality.
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| 13. |
- van Buggenhout, Sandra, et al.
(författare)
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Structural design of natural plant based foods to promote nutritional quality
- 2012
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Ingår i: Trends in Food Science and Technology. - : Elsevier BV. - 0924-2244 .- 1879-3053. ; 24:1, s. 47-59
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- During traditional industrial processing of fruit and vegetable derived foods, consideration of the eventual retention, bio-accessibility or bio-availability of nutrients has hitherto been a secondary priority. Indeed standard processing of soups and sauces involves treating all ingredients in a similar way, usually by prolonged heat treatment and results in both lowered nutritional value and sensory quality of food products. Such products are typically structured using various additives including starches, gums and stabilizers, which consumers regard as unnatural, rather than exploiting the endogenous structuring potential of the fruit and vegetable ingredients as available at the farm gate. Recent studies undertaken within the EU sponsored 'Healthy Structuring' project have shown how to design an industrially manufactured product with good sensory qualities that is natural and nutritious. The strategy has been to use the inherent structural and nutritional properties of the raw material ingredients, on the one hand to ensure the textural quality of the final product without the use of artificial gums or stabilizers and, on the other hand to optimize the nutritional quality of the final product. This review briefly summarizes both the approach taken and the results obtained within the project.
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| 14. |
- Guo, Annie, et al.
(författare)
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Choice of health metrics for combined health and environmental assessment of foods and diets : A systematic review of methods
- 2022
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Ingår i: Journal of Cleaner Production. - : Elsevier Ltd. - 0959-6526 .- 1879-1786. ; 365
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Tidskriftsartikel (refereegranskat)abstract
- Evidence-based scientific methods combining health and environmental perspectives are urgently required to support policy decisions and recommendations for more sustainable food systems. This review provides a systematic overview of health metrics and methods to combine health and environmental assessment of foods and diets. Key methodological considerations of importance for best practices are highlighted as well as trends over the past decade, and future research needs. A systematic literature review was performed in the databases Scopus, Dimensions and Pub Med. Eligible articles combined health impact and environmental assessment of food and were published in peer-reviewed scientific journals between 2010 and 2020. Differences in method choices were highlighted based on study approach, dietary baseline data, dietary exposure, dietary-related health outcome, method for health assessment, choice of health metric, environmental outcome and method for combined health and environmental assessment. A total of 33 articles using nine different health metrics in combination with environmental assessment of foods were identified. Avoided, averted, delayed or preventable deaths or cases, followed by disability- or quality-adjusted life years, and hazard ratio were the health metrics most commonly used. Three principal methods to combine health and environmental assessment of foods and diets were identified; parallel assessment (n = 26), scaled assessment (n = 7) and integrated assessment (n = 1). Method choices affecting reliability and uncertainty, as well as suitability for different purposes were described. Over the past decade, a strong acceleration in the research field of combined health and environmental assessment of food was noted, both regarding number of published studies and method development for more holistic sustainability assessments. Transition towards more sustainable food choices offers great potential to improve public health and reduce environmental impact from the food system. This review identified several health metrics that are suitable for use in methods combining health and environmental dimensions when studying the sustainability of food systems. For best practices, improved knowledge on how multi-criteria sustainability indicators can be assessed, communicated and implemented by different actors along the food supply chain is required. © 2022 The Authors
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| 15. |
- Ross, Alastair, 1976, et al.
(författare)
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Perspective: A Definition for Whole-Grain Food Products-Recommendations from the Healthgrain Forum
- 2017
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Ingår i: Advances in nutrition (Bethesda, Md.). - : Elsevier BV. - 2161-8313 .- 2156-5376. ; 8:4, s. 525-531
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Tidskriftsartikel (refereegranskat)abstract
- Whole grains are a key component of a healthy diet, and enabling consumers to easily choose foods with a high whole-grain content is an important step for better prevention of chronic disease. Several definitions exist for whole-grain foods, yet these do not account for the diversity of food products that contain cereals. With the goal of creating a relatively simple whole-grain food definition that aligns with whole-grain intake recommendations and can be applied across all product categories, the Healthgrain Forum, a not-for-profit consortium of academics and industry working with cereal foods, established a working group to gather input from academics and industry to develop guidance on labeling the whole-grain content of foods. The Healthgrain Forum recommends that a food may be labeled as "whole grain" if it contains ≥30% whole-grain ingredients in the overall product and contains more whole grain than refined grain ingredients, both on a dry-weight basis. For the purposes of calculation, added bran and germ are not considered refined-grain ingredients. Additional recommendations are also made on labeling whole-grain content in mixed-cereal foods, such as pizza and ready meals, and a need to meet healthy nutrition criteria. This definition allows easy comparison across product categories because it is based on dry weight and strongly encourages a move from generic whole-grain labels to reporting the actual percentage of whole grain in a product. Although this definition is for guidance only, we hope that it will encourage more countries to adopt regulation around the labeling of whole grains and stimulate greater awareness and consumption of whole grains in the general population.
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| 16. |
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| 17. |
- Lazarte, Claudia E., et al.
(författare)
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Phytate, zinc, iron and calcium content of common Bolivian food, and implications for mineral bioavailability
- 2015
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Ingår i: Journal of Food Composition and Analysis. - : Elsevier BV. - 0889-1575 .- 1096-0481. ; 39, s. 111-119
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Tidskriftsartikel (refereegranskat)abstract
- The content of zinc, iron, calcium and phytate in the 16 most consumed foods from 5 villages in a tropical rural area of Bolivia was analyzed. The fooditems were selected according to a completed food frequency questionnaire. Minerals were analyzed by atomic absorption and phytates by HPIC chromatography. The molar ratios of phytate:mineral are presented as indication of the mineral bioavailability. Within the analyzed food, quinoa is a potential source of minerals: zinc 3.65, iron 5.40 and calcium 176 mg/100 g; however, it also has the highest content of phytate 2060 mg/100 g. Cereals and legumes showed high concentration of phytates (from 142 to 2070 mg/100 g), roots and tubers have lower concentrations (from 77 to 427 mg/100 g). In general, both phytate contents and molar ratios Phy:Zn (phytate:zinc), Phy:Fe (phytate:iron) and Phy:Ca (phytate:calcium) in most of the analyzed foods were at levels likely to inhibit the absorption of these minerals. Significant positive associations (p < 0.01) were found between the level of phytate and minerals in food, for zinc (r = 0.714), iron (r = 0.650) and calcium (r = 0.415). The results compared to data from USA or from Bolivia showed some discrepancies, confirming the need for more reliable data for dietary evaluations and interventions. (c) 2015 Elsevier Inc. All rights reserved.
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| 18. |
- Nyflött, Åsa, 1986-
(författare)
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Structure-Performance Relations of Oxygen Barriers for Food Packaging
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Food packaging should ensure the safety and quality of food, minimize spoilage and provide an easy way of storing and handling it. Barrier coatings are generally used to meet the demands placed on fibre-based food packages, as these have the ability to regulate the amount of gases that can enter them. Some gases are detrimental to food quality: oxygen, for example, initiates lipid oxidation in fatty foods. Using both experimental data and computer modelling, this thesis explains some aspects of how the structure of barrier coatings influences the mass transport of oxygen with the aim of obtaining essential knowledge that can be used to optimize the performance of barriers.Barrier coatings are produced from polyvinyl alcohol and kaolin blends that are coated onto a polymeric support. The chemical and physical structures of these barriers were characterized according to their influence on permeability in various climates. At a low concentration of kaolin, the crystallinity of polyvinyl alcohol decreased; in the thinner films, the kaolin particles were orientated in the basal plane of the barrier coating. The experimental results indicated a complex interplay between the polymer and the filler with respect to permeability.A computer model for permeability incorporating theories for the filled polymeric layer to include the polymer crystallinity, addition of filler, filler aspect ratio and surrounding moisture was developed. The model shows that mass transport was affected by the aspect ratio of the clay in combination with the clay concentration, as well as the polymer crystallinity. The combined model agreed with the experiments, showing that it is possible to combine different theories into one model that can be used to predict the mass transport.Four barrier coatings: polyethylene, ethylene vinyl alcohol + kaolin, latex + kaolin and starch were evaluated using the parameters of greenhouse gas emissions and product costs. After the production of the barrier material, the coating process and the end-of-life handling scenarios were analysed, it emerged that starch had the lowest environmental impact and latex + kaolin had the highest.
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| 19. |
- Singh, Sukhdeep, 1988, et al.
(författare)
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Influence of Hot Isostatic Pressing on the Hot Ductility of Cast Alloy 718 : The Effect of Niobium and Minor Elements on the Liquation Mechanism
- 2020
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Ingår i: Metallurgical and Materials Transactions. A. - : Springer. - 1073-5623 .- 1543-1940. ; 51:12, s. 6248-6257
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Tidskriftsartikel (refereegranskat)abstract
- The influence of two hot isostatic pressing (HIP) treatments on liquation behavior was investigated and compared with regard to the extent of heat-affected zone liquation cracking in cast Alloy 718. The extent of liquation was seen to increase after HIP treatment at 1190 °C due to solute changes caused by the homogenization of Nb, which contributed to extensive grain boundary melting. The HIP treatment at 1120 °C exhibited lower liquation with contributions from particle liquation of the Laves phase and constitutional liquation of NbC carbides. This was also reflected in a lower ductility recovery temperature, with slower recovery for the former due to the extensive liquation. Interestingly, the nil ductility temperatures were both below the predicted equilibrium solidus of the alloy, which suggests that the ductility drop is related to liquation caused by solute segregation at the grain boundaries. © 2020, The Author(s).
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| 20. |
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| 21. |
- Olsson, E E M, et al.
(författare)
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Flow and heat transfer from multiple slot air jets impinging on circular cylinders
- 2005
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Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 67:3, s. 273-280
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Tidskriftsartikel (refereegranskat)abstract
- This study presents flow and heat transfer predictions of multiple slot air jets impinging on circular cylinders using CFD (computational fluid dynamics). The distribution of Nusselt numbers around the cylinders for different Reynolds numbers (23,000-100,000), distances between the jets, and openings between them was determined for two and three jets and compared to simulations of a single jet. The flow characteristics and the heat transfer distribution around the cylinders are found to be dependent on the distance and the opening between the jets. The interaction between two jets is found to be most advantageous. The heat transfer increases for higher Reynolds number in general; for two jets the heat transfer in the stagnation point is Nu(s) = 0.20Re(0.68). For three jets, the heat transfer distribution is different on the outer cylinders, as compared to the cylinder in the centre. (C) 2004 Elsevier Ltd. All rights reserved.
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| 22. |
- Olsson, E E M, et al.
(författare)
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Heat transfer from a slot air jet impinging on a circular cylinder
- 2004
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Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 63:4, s. 393-401
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Tidskriftsartikel (refereegranskat)abstract
- Heat transfer from a slot air jet impinging on a cylinder shaped food product placed on a solid surface in a semi-confined area as investigated using computational fluid dynamics (CFD). Simulations of a cylinder in cross flow with the k-epsilon, k-omega and SST models in CFX 5.5 were compared with measurements in the literature. The SST model predicts the heat transfer better than the other models and is therefore used in this study. The distribution of the local Nusselt numbers around the cylinder for various Reynolds numbers (23,000-100,000), jet-to-cylinder distances, H/d (2-8), and cylinder curvature, d/D (0.29-1.14) was determined. The results show that the local Nusselt numbers varies around the surface of the cylinder and that the average Nusselt number and the stagnation point Nusselt number increases with increasing Reynolds numbers and surface curvature but has little dependency on the jet-to-cylinder distance. The result is Nu(m) = 0.14Re(0.65)(H/d)(-0.077)(d/D)(0.32) and Nu(s) = 0.46Re(0.59)(H/d)(-0.026)(d/D)(0.32). (C) 2003 Elsevier Ltd. All rights reserved.
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| 23. |
- Mura, Ernesto, 1974, et al.
(författare)
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Pressure drop in dairy evaporators: Experimental study and friction factor modelling
- 2017
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Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774. ; 195, s. 128-136
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Tidskriftsartikel (refereegranskat)abstract
- The pressure drop that occurs during the falling film evaporation of dairy products is related to the downward co-flowing vapour and directly affects the saturation temperature of the product, resulting in a non-constant thermal driving force of the process along the evaporator. Frictional forces are the major contributor to the pressure drop, and the friction factor is a crucial parameter in reliably estimating the pressure drop. In the present study, the absolute vapour flow pressure losses during falling film evaporation of dairy products were measured using an experimental internal tube evaporator set-up. To simulate real industrial conditions, experiments were conducted by varying the co-flow inlet velocity (from 0 to 37 ms(-1)) over a wide range of product dry solid content DC (from DC = 0%-50%). Results obtained at DC = 0% show that the experimental approach is consistent when measurements are compared to the well-known Wallis correlation. A large number of experimental data has been obtained for DC between 13 and 40% for which the pressure losses have a strong dependence from the co-flowing vapour rate; in some specific cases, the influence of the surface bubbling phenomena has been put in evidence. The presented results, have been used to calibrate a new accurate correlation for the friction factor (4f(tv)) coefficient showing a squared residual of R-2 = 0.93.
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| 24. |
- Raaholt, Birgitta, et al.
(författare)
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Continuous tubular microwave heating of homogeneous foods: evaluation of heating uniformity
- 2016
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Ingår i: The Journal of microwave power and electromagnetic energy. - London : Taylor & Francis Group. - 0832-7823. ; 50:1, s. 43-65
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Tidskriftsartikel (refereegranskat)abstract
- A pilot-scale process for continuous in-flow microwave processing of foods, designed and implemented at SP Food and Bioscience, was evaluated for heat treatment of a homogeneous model food for high-temperature short-time (HTST) conditions, at constant total input microwave power, at 2450 MHz. The microwave system has three consecutive cavities, one excited by the TM020 microwave mode that heats primarily in the tube centre, and two TM120 mode cavities that heat primarily in the tube periphery. The temperature uniformity of the homogeneous model food after microwave heating is here evaluated in terms of spatial distribution, for different set-ups of input microwave power in each cavity and for different order of the placement of the cavities, while maintaining the total input microwave power. The microwave heating uniformity is evaluated, based on measured and calculated radial temperature profiles. Combined TM020 and TM120 heating was found to result in more uniform heating by means of spatial temperature uniformity over the tube cross section. Furthermore, appropriately selected microwave power distribution between the centre and periphery heating cavities results in a stable heating profile in the studied food, that differs only about 10 °C or less between highest and lowest average values directly after microwave heating.
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| 25. |
- Teixeira, Cristina, 1986
(författare)
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Barley malt products for improved intestinal health
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Barley is a good source of dietary fibre, particularly β-glucan and arabinoxylan, to increase formation of short-chain fatty acids (SCFAs). Butyric and propionic acid are involved in the preservation of colonic barrier function, thus decreasing the risk of inflammation. Previous studies have shown that malting barley increased formation of butyric acid in caecum of rats and had abundance of butyrate-producing bacteria than unmalted barley. However, this differed between malts, probably due to the differences in fibre functional characteristics.The aim of this work was to investigate the impact of barley variety and malting conditions on the functional properties of the dietary fibre in barley malt products, with the overall aim of improving intestinal health. Focus was given to β-glucan functional properties, but also arabinoxylan. The influence of these fibres on substrate delivery to the colon, SCFAs formation, microbiota composition and gene expression was investigated.In the first study, rats fed commercial barley malts had a higher level of butyric and propionic acids in the caecum and portal serum than those fed control diets (cellulose). β-glucan with broader molecular weight seemed to better increase the caecal SCFA formation. In addition, the malts contributed to improved mucosal barrier function and inflammatory state by decreasing mRNA expression of tight junction protein and toll-like receptors in the small intestine and distal colon. However, malt with high amounts of advanced glycation end-products seemed to attenuate the effect on occludin (tight junction protein) in the small intestine.To evaluate the possibility of using malting to tailor functional characteristics of the fibre, three barley varieties were malted using different temperatures and levels of lactic acid in the steeping water. The extent to which barley components changed depended on the variety. Steeping at 35°C with 0.4% lactic acid preserved soluble fibre and β-glucan content better, but not the soluble arabinoxylan, compared with steeping at 15°C and without lactic acid. However, no changes in β-glucan molecular weight (> 10 kDa) were observed. β-glucan molecular weight analysed with AF4 at a wider molecular weight range (> 2 kDa), was shown to be affected by both variety and processing (steeping or mashing) to different extents. Addition of proteolytic enzymes shifted the β-glucan of high molecular weight to a lower molecular weight range, suggesting that proteins are involved in the structure of β-glucan, which might result in an apparently higher molecular weight.After passage through a dynamic gastrointestinal in vitro model (TIM-1), it was observed that β-glucan molecular weight gradually decreased in the different barley products investigated. The longer in vitro transit time of soluble fibre and β-glucan was related to their high content and/or molecular weight, which also seemed to be linked to a higher degree of fermentation in an in vivo model (rats).In the last study it was investigated the differences of microbiota composition in rats fed barley malt products. Rats fed malt products had higher microbiota diversity (negatively associated with ulcerative colitis and obesity) than those fed barley extracts rich in arabinoxylan or β-glucan, and control. Malts contributing with a higher content of β-glucan increased the abundance of Lactobacillus and Blautia and tended to increase butyric acid, whereas soluble arabinoxylan increased Akkermansia and propionic acid in the caecum. By mixing barley products (brewers’ spent grain and malt) it was possible to modulate the microbiota into an intermediary abundance of taxa, with slight increase of butyric acid compared with malt alone.In conclusion, malting seems to be a potential processing method for tailoring barley composition to promote intestinal health. Both the selection of barley variety and the processing conditions affected the composition of malt products. The resulting barley products with a high content of soluble fibre, β-glucan and soluble arabinoxylan, enhanced colon fermentation, microbiota composition and, to some extent, the SCFA formation.
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| 26. |
- Wikström, Fredrik, 1964-, et al.
(författare)
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Packaging Strategies That Save Food : A Research Agenda for 2030
- 2019
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Ingår i: Journal of Industrial Ecology. - : Wiley-Blackwell. - 1088-1980 .- 1530-9290. ; 23:3, s. 532-540
-
Tidskriftsartikel (refereegranskat)abstract
- Summary Thoroughly considering and optimizing packaging systems can avoid food loss and waste. We suggest a number of issues that must be explored and review the associated challenges. Five main issues were recognized through the extensive experience of the authors and engagement of multiple stakeholders. The issues promoted are classified as follows: (1) identify and obtain specific data of packaging functions that influence food waste; (2) understand the total environmental burden of product/package by considering the trade‐off between product protection and preservation and environmental footprint; (3) develop understanding of how these functions should be treated in environmental footprint evaluations; (4) improve packaging design processes to also consider reducing food waste; and (5) analyze stakeholder incentives to reduce food loss and waste. Packaging measures that save food will be important to fulfill the United Nations Sustainable Development goal to halve per capita global food waste at the retail and consumer levels and to reduce food losses along production and supply chains.
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| 27. |
- Harrysson, Hanna, 1987, et al.
(författare)
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Strategies for Improving the Protein Yield in pH-Shift Processing of Ulva lactuca Linnaeus: Effects of Ulvan Lyases, pH-Exposure Time, and Temperature
- 2019
-
Ingår i: Acs Sustainable Chemistry & Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 7:15, s. 12688-12691
-
Tidskriftsartikel (refereegranskat)abstract
- Globally, there is a need for novel vegetarian protein sources. We recently showed that the pH-shift process, using alkaline protein solubilization followed by isoelectric precipitation, is an efficient way to produce extracts with high protein concentrations from Ulva lactuca (>50% on a dry matter basis). However, the total protein yield was low, and to improve this, the effects of adding ulvan lyase, preincubating the seaweed homogenate at pH 8.5 and using different protein extraction temperatures (8 degrees C, RT and 40 degrees C), were evaluated in this study. Addition of ulvan lyase reduced protein solubility but increased the precipitation. Incubation at pH 8.5, without ulvan lyase added, significantly increased both protein solubility and precipitation at 8 degrees C and RT. Temperature per se had no effect on protein solubility, while protein precipitation increased with decreasing temperature. Highest protein yield (29%) was achieved when keeping the process at 8 degrees C with a preincubation step at pH 8.5 for 1 h. By these process modifications, the yield was 3.2 times higher than achieved by the control process (9.2%).
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| 28. |
- Bryngelsson, David, 1981
(författare)
-
Land-use competition and agricultural greenhouse gas emissions in a climate change mitigation perspective
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Productive land for food production, bioenergy, or preservation of nature is a limited resource. Climate change mitigation puts additional pressure on land via higher demand for bioenergy to replace fossil fuels and via restrictions on deforestation—two processes that limit the availability of land for food produc- tion, and may thus also raise food prices. Methane and nitrous oxide emis- sions from agriculture may also need to be reduced to efficiently mitigate climate change. This thesis deals with this in three ways.In papers I–II, we estimate greenhouse gas emissions from food production for current diets and expected future developments, together with alternative di- etary developments and potential technical improvements in the agricultural sec- tor. Costs and possibilities for reaching climate goals are analyzed for the differ- ent diets. The results indicate that a phase out of ruminant products would cut mitigation cost in half, for staying below a 2◦C limit, and it may be necessary if the climate sensitivity is high.In papers III–IV, a conceptual and transparent partial equilibrium model of global land-use competition is developed, analyzed and applied. The model is to a large degree analytically explored and price differentials between crops are derived. The model is subjected to a detailed characterization of its mechanisms and parameters that are critical to the results. We conclude that the total amount of productive agricultural area and bioenergy yields are of crucial importance to the price impacts from large-scale introduction of bioenergy. We also show how limiting bioenergy production to marginal land could be difficult to implement in practice.In paper V, we use two established indicators for poverty and sensitivity to food-price changes to capture peoples’ vulnerability to rising food-prices in four Sub-Sahara African countries/regions. In contrast to previous studies, we include all food products instead of just one or a few main staples. We found that the vast majority of people are net consumers of food and that the inclusion of more than main staples increases their net position as consumers and thus vulnerability to high food prices.
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| 29. |
- Wu, Haizhou, 1987, et al.
(författare)
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Lipid oxidation and antioxidant delivery systems in muscle food
- 2022
-
Ingår i: Comprehensive Reviews in Food Science and Food Safety. - : Wiley. - 1541-4337. ; 21:2, s. 1275-1299
-
Forskningsöversikt (refereegranskat)abstract
- Lipid oxidation accelerates quality deterioration in muscle-based foods (fish, red meat, and poultry), resulting in off-odors/flavors, color problems, texture defects, and safety concerns. Adding antioxidants is one approach to control lipid oxidation, and several delivery strategies have been applied, such as supplementing antioxidants to the feed, direct mixing into minces, or, for whole muscle pieces; spraying, glazing, and injection. However, some issues linked to these technologies hinder their wide utilization, such as low effectiveness, noncompatibility with clean label, and off-flavor. These shortcomings have promoted the development of new antioxidant delivery technologies. In this review, the main focus is on the principles, characteristics, and implementation of five novel antioxidant delivery methods in different types of muscle food products. Their advantages and drawbacks are also summarized, plus comments about future trends in this area. Among novel routes to deliver antioxidants to muscle foods are, for whole tissues, recyclable dipping solutions; for minces, encapsulation; and, for both minces and whole tissues, cross-processing with nonmuscle antioxidant-containing raw materials as well as applications of edible films/coatings and active packaging. Advantages of these technologies comprise, for example, low price, the possibility to control the antioxidant release rate, overcoming strong aromas from natural antioxidants, and allowing antioxidant-containing raw materials from the food industry to be valorized, providing an opportunity for more circular food production.
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| 30. |
- Schott, Florian, et al.
(författare)
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Structural formation during bread baking in a combined microwave-convective oven determined by sub-second in-situ synchrotron X-ray microtomography
- 2023
-
Ingår i: Food Research International. - : Elsevier Ltd. - 0963-9969 .- 1873-7145. ; 173
-
Tidskriftsartikel (refereegranskat)abstract
- A new concept has been developed for characterizing the real-time evolution of the three-dimensional pore and lamella microstructure of bread during baking using synchrotron X-ray microtomography (SRµCT). A commercial, combined microwave-convective oven was modified and installed at the TOMCAT synchrotron tomography beamline at the Swiss Light Source (SLS), to capture the 3D dough-to-bread structural development in-situ at the micrometer scale with an acquisition time of 400 ms. This allowed characterization and quantitative comparison of three baking technologies: (1) convective heating, (2) microwave heating, and (3) a combination of convective and microwave heating. A workflow for automatic batchwise image processing and analysis of 3D bread structures (1530 analyzed volumes in total) was established for porosity, individual pore volume, elongation, coordination number and local wall thickness, which allowed for evaluation of the impact of baking technology on the bread structure evolution. The results showed that the porosity, mean pore volume and mean coordination number increase with time and that the mean local cell wall thickness decreases with time. Small and more isolated pores are connecting with larger and already more connected pores as function of time. Clear dependencies are established during the whole baking process between the mean pore volume and porosity, and between the mean local wall thickness and the mean coordination number. This technique opens new opportunities for understanding the mechanisms governing the structural changes during baking and discern the parameters controlling the final bread quality. © 2023 The Author(s)
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| 31. |
- Risman, PO, 1943, et al.
(författare)
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Retro-modelling of a dual resonant applicator and accurate dielectric properties of liquid water from −20 °C to +100 °C
- 2007
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Ingår i: Measurement Science and Technology. - : IOP Publishing. - 0957-0233 .- 1361-6501. ; 18, s. 959-966
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Tidskriftsartikel (refereegranskat)abstract
- A critical analysis is made of literature reports on the dielectric properties of pure water from liquid water supercooled at −20 ◦C, to +100 ◦C, in principle in the frequency range 0 to 3 GHz. Measurements using completemulti-step numerical modelling of a dual resonant cavity at about 920 MHz and 2230 MHz are presented. The measured data at about +20 ◦C are used as reference for the calculation of data at other temperatures. Due to the high resolution and considerations of various error sources, the resultingaccuracy becomes high and allows the construction of improved empiricalformulae for the Debye relaxation behaviour.
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| 32. |
- Ovaska, Sami-Seppo, et al.
(författare)
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Characterization of rapeseed oil/coconut oil mixtures and their penetration into hydroxypropylated-starch-based barrier coatings containing an oleophilic mineral
- 2016
-
Ingår i: Progress in organic coatings. - : Elsevier BV. - 0300-9440 .- 1873-331X. ; 101, s. 569-576
-
Tidskriftsartikel (refereegranskat)abstract
- A study was conducted that demonstrated that the blending of edible oils leads to changes in surface tension, thermal properties, viscosity, and oil penetration times through a barrier-coated paperboard. The results emphasize the significance of testing the oil and grease resistance (OGR) oil blends in order-to verify the suitability of the packaging material for real-life end-use applications. The results of the OGR determinations suggest that hydroxypropylated-starch-based composite coatings containing an oleophilic high aspect ratio mineral can be tailored for food shaving different fatty acid compositions by varying the pigmentation level. Compared to standard OGR tests, confocal laser scanning microscopy (CLSM)-based techniques make it possible to evaluate the oil penetration time and its diffusion behavior very accurately, both inside the coating layer and in the bulk matrix. It was found that, at room temperature, coconut oil tends to crystallize inside the substrate, inducing swelling of the coating layer, which probably has an influence on the physicomechanical properties of the packaging material.
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| 33. |
- Kovács, Tamás
(författare)
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Flow and turbulence in the discharge stream of different agitators for stirred tanks
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, the fluid dynamic properties of the conventional Rushton turbine and another impeller type, the Scaba Radial flow Gas dispersing Turbine (with six concave blades) are compared. For comparison, point-wise velocity measurements were made in the discharge of the two turbine types using Hot-Wire Anemometry in constant temperature mode (CTA) with a split film probe. For the time-averaged flow and turbulent properties, good agreement was found for the turbines using both a representation of data based on an analogy to a jet, and the power input. These comparisons were not available when a larger 6SRGT was studied, due to the presence of the axial pumping impellers. These turbines lift the radial jet in the 6SRGT discharge, making the tangential velocity in the impeller centreline significantly lower. Because of the effect of the rotating blades, the measured time series is considered to be the superposition of the periodic (pseudo-turbulent) and the random turbulent signal. These two parts were separated by eliminating or retaining the associated frequencies in the Fourier spectrum. Using plane projections of the phase portraits of the deterministic part, the dynamics of pseudo-turbulence were found to be very similar for the 6SRGT turbine regardless of the diameter or agitation rate. Somewhat slightly different projections were obtained for the 6RT turbine. From the profile measurement, the lack of trailing vortices was concluded in the case of the 6SRGT turbines, and the turbulence was found to be characterised by the same integral length scales and Eulerian time scales in both cases at pilot scale.
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| 34. |
- Moshtaghian, Hanieh, et al.
(författare)
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Challenges for Upcycled Foods : Definition, Inclusion in the Food Waste Management Hierarchy and Public Acceptability
- 2021
-
Ingår i: Foods. - : MDPI AG. - 2304-8158. ; 10:11
-
Forskningsöversikt (refereegranskat)abstract
- Upcycled foods contain unmarketable ingredients (e.g., damaged food produce, by-products and scraps from food preparation) that otherwise would not be directed for human consumption. Upcycled food is a new food category and thus faces several challenges, such as definition development, inclusion in the food waste management hierarchy and public acceptability. This review provides an overview of these three challenges. The upcycled food definitions have been developed for research, food manufacturers, and multi-stakeholders use. Thus, there is a need for a consumer-friendly definition for the general public. A simplified definition is proposed to introduce these foods as environmentally friendly foods containing safe ingredients that otherwise would not have gone to human consumption such as damaged food produce, by-products and scraps from food preparation. Moreover, an updated version of the food waste management hierarchy has been proposed by including the production of upcycled foods as a separate waste management action that is less preferable than redistribution but more favourable than producing animal feed. Furthermore, consumer sociodemographic characteristics and beliefs, as well as food quality cues and attributes, were identified as crucial factors for the public acceptability of these foods. Future research should address these challenges to facilitate the introduction of upcycled foods.
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| 35. |
- Muncke, J., et al.
(författare)
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Scientific Challenges in the Risk Assessment of Food Contact Materials
- 2017
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Ingår i: Environmental health perspectives. - 1552-9924. ; 125:9
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Food contact articles (FCAs) are manufactured from food contact materials (FCMs) that include plastics, paper, metal, glass, and printing inks. Chemicals can migrate from FCAs into food during storage, processing, and transportation. Food contact materials' safety is evaluated using chemical risk assessment (RA). Several challenges to the RA of FCAs exist. OBJECTIVES: We review regulatory requirements for RA of FCMs in the United States and Europe, identify gaps in RA, and highlight opportunities for improving the protection of public health. We intend to initiate a discussion in the wider scientific community to enhance the safety of food contact articles. DISCUSSION: Based on our evaluation of the evidence, we conclude that current regulations are insufficient for addressing chemical exposures from FCAs. RA currently focuses on monomers and additives used in the manufacture of products, but it does not cover all substances formed in the production processes. Several factors hamper effective RA for many FCMs, including a lack of information on chemical identity, inadequate assessment of hazardous properties, and missing exposure data. Companies make decisions about the safety of some food contact chemicals (FCCs) without review by public authorities. Some chemical migration limits cannot be enforced because analytical standards are unavailable. CONCLUSION: We think that exposures to hazardous substances migrating from FCAs require more attention. We recommend a) limiting the number and types of chemicals authorized for manufacture and b) developing novel approaches for assessing the safety of chemicals in FCAs, including unidentified chemicals that form during or after production. https://doi.org/10.1289/EHP644.
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| 36. |
- Olsson, Eva
(författare)
-
Jet Impingement and Infrared Heating of Cylindrical Foods. Flow and Heat Transfer Studies
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Rapid heat transfer methods such as jet impingement and infrared radiation can be used to speed up thermal processing in the food industry. The heating rate affects important food characteristics, such as colour. Jet impingement consists of directed jets of air with a high velocity that impinge on the food surface, which reduces the velocity boundary layer between the air and surface and gives a fast heat transfer. Infrared heating is a radiative heat transfer method with instant and effective heating of the food product, without heating the surrounding air. Flow and heat transfer from single and multiple jets impinging on a circular cylinder placed on a flat surface were studied numerically by computational fluid dynamics (CFD) simulations using the k-? SST and RSM models. The results concerning velocity obtained by CFD were generally in good agreement with experimental measurements using particle image velocimetry (PIV). The heat transfer distribution on the cylinder surface, expressed as local heat transfer coefficients, was non-uniform due to air flow characteristics that influenced the boundary layer thickness. The heat transfer was highest on the top of the cylinder, and lower close to the separation point and on the back of the cylinder. In addition to making CFD simulations, the local heat transfer coefficients were determined by an inverse heat transfer method, including a sensitivity analysis, using temperature profiles in the cylinder at different positions. The heat transfer coefficients were generally higher than what was predicted by CFD. The interaction between multiple jets strongly affected the heat transfer around the cylinder. The distance and opening between the jets were found to be important to achieving a high and even heat transfer rate using multiple jets. Jet impingement and infrared heating simultaneously was studied using CFD, which showed that there is a synergistic effect when the two heating methods are combined. A higher heat transfer was achieved by combining the methods than by using each method separately. The effect of impingement and infrared heating on colour and crust formation on partially baked baguettes was investigated experimentally. Impingement and infrared heating gave different temperature profiles in the crust, which resulted in different colour development and crust formation. A rapid heating increased the rate of colour development and shortened the total heating time, which resulted in a thin crust and reduction in the total moisture loss. The combination of jet impingement and infrared made it possible to create product properties that cannot be achieved by use of the heating methods alone. A thicker crust and better heating in the centre of the bread could only be achieved by combining infrared and impingement. For industrial thermal processes, prediction of flow and heat transfer with CFD can be used to design equipment and processes that offer optimal heat transfer to the product, thus resulting in high and even product quality.
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| 37. |
- Palacios-Argüello, Laura, et al.
(författare)
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The Role of Food Hubs in Enabling Local Sourcing for School Canteens
- 2020
-
Ingår i: Food Supply Chains in Cities: Modern Tools for Circularity and Sustainability. - Cham : Springer International Publishing. ; , s. 233-263
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Public authorities are increasingly interested in fostering short food supply chains. Starting by increasing the share of local and organic food in school canteens has a big potential but requires the redesign of the physical distribution system to make short food supply chains competitive and sustainable. Food Hubs (FH) have been identified in the literature as enablers of sustainable and efficient food supply chains. This chapter describes the functions and characteristics of FH used for school canteens, and analyses how these FH should be designed to increase local and organic products share in school canteens. The results show that changing allocation from the current one-based on administrative subdivision-to a geographical proximity-based allocation could lead to 25% reductions in vehicle-kilometres travelled.
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| 38. |
- Andersson, Helene, 1983, et al.
(författare)
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Effects of molecular weight on permeability and microstructure of mixed ethyl-hydroxypropyl-cellulose films
- 2013
-
Ingår i: European Journal of Pharmaceutical Sciences. - : Elsevier BV. - 0928-0987 .- 1879-0720. ; 48:1-2, s. 240-248
-
Tidskriftsartikel (refereegranskat)abstract
- Films of ethyl cellulose (EC) and water-soluble hydroxypropyl cellulose (HPC) can be used for extended release coatings in oral formulations. The permeability and microstructure of free EC/HPC films with 30% w/w HPC were studied to investigate effects of EC molecular weight. Phase separation during film spraying and subsequent HPC leaching after immersion in aqueous media cause pore formation in such films. It was found that sprayed films were porous throughout the bulk of the films after water immersion. The molecular weight affected HPC leaching, pore morphology and film permeability; increasing the molecular weight resulted in decreasing permeability. A model to distinguish the major factors contributing to diffusion retardation in porous films showed that the trend in permeability was determined predominantly by factors associated with the geometry and arrangement of pores, independent of the diffusing species. The film with the highest molecular weight did, however, show an additional contribution from pore wall/permeant interactions. In addition, rapid drying and increasing molecular weight resulted in smaller pores, which suggest that phase separation kinetics affects the final microstructure of EC/HPC films. Thus, the molecular weight influences the microstructural features of pores, which are crucial for mass transport in EC/HPC films.
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| 39. |
- Iftekhar, A., et al.
(författare)
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Application of Blockchain and Internet of Things to Ensure Tamper-Proof Data Availability for Food Safety
- 2020
-
Ingår i: Journal of Food Quality. - : Hindawi Limited. - 0146-9428 .- 1745-4557. ; 2020
-
Tidskriftsartikel (refereegranskat)abstract
- Food supply chain plays a vital role in human health and food prices. Food supply chain inefficiencies in terms of unfair competition and lack of regulations directly affect the quality of human life and increase food safety risks. This work merges Hyperledger Fabric, an enterprise-ready blockchain platform with existing conventional infrastructure, to trace a food package from farm to fork using an identity unique for each food package while keeping it uncomplicated. It keeps the records of business transactions that are secured and accessible to stakeholders according to the agreed set of policies and rules without involving any centralized authority. This paper focuses on exploring and building an uncomplicated, low-cost solution to quickly link the existing food industry at different geographical locations in a chain to track and trace the food in the market.
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| 40. |
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| 41. |
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| 42. |
- Pardillo-Baez, Yinef, et al.
(författare)
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Local and organic food distribution systems: towards a future agenda
- 2020
-
Ingår i: Operations and Supply Chain Management. - : OSCM Forum. - 1979-3561 .- 2579-9363. ; 13:4, s. 336-348
-
Tidskriftsartikel (refereegranskat)abstract
- There has been an increasing consumer demand for local and organic food as they are considered to be more sustainable, ecological and healthier. The ‘conventional’ long food distribution system is not sufficient to fulfill the current needs. Consequently, short distribution systems for local and organic food have been gaining popularity, that is not only sustainable but also contributes to food security and satisfies local consumer demand. One such short distribution systems are alternative food networks (AFNs). The AFNs have emerged as a promising provisioning system for local and organic food that promotes economical, environmental and social sustainability and respect for farming tradition. However, the AFNs are facing challenges in increasing the distribution of local and organic food in the long term. The purpose of the paper is to make a review of the existing short food distribution systems for local and organic food and propose a research agenda. In order to achieve this, a literature review is conducted and different food distribution channels within AFNs are studied. The challenges for each food distribution channel are identified and then compared to ‘conventional’ distribution systems. The main finding of the study is a framework of main challenges of short food distribution channels within AFNs. The practical implication is generic criteria to consider while designing a short food distribution system that closely connects consumers and farmers of local and organic food. The policy implication is to create favorable conditions to encourage short food distribution systems in the long term.
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| 43. |
- Sarmad, Shokat, et al.
(författare)
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Vapor-liquid equilibrium of ionic liquids
- 2020
-
Ingår i: Encyclopedia of ionic liquids. - Singapore : Springer. - 9789811067396 - 9789813342200 ; , s. 1-22
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 44. |
- Zhou, Mi, 1985, et al.
(författare)
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Investigation of the cohesive strength of membrane fouling layers formed during cross-flow microfiltration: The effects of pH adjustment on the properties and fouling characteristics of microcrystalline cellulose
- 2019
-
Ingår i: Chemical Engineering Research and Design. - : Elsevier BV. - 0263-8762 .- 1744-3563. ; 149, s. 52-64
-
Tidskriftsartikel (refereegranskat)abstract
- Fluid dynamic gauging was used to investigate the cohesive strength of the membrane fouling layer formed during cross-flow microfiltration of microcrystalline cellulose. Fouling behaviour was compared at two pH levels (i.e. different surface charges of the particles and membranes) with two membranes (i.e. regenerated cellulose and polyethersulphone). It was found that a suspension at low pH, where the surface charge of the particles is close to zero, resulted in thicker and stronger surface fouling layers (668 ± 66 μm thick at a shear stress of 36 Pa for the regenerated cellulose membrane). The permeate flux was reduced by 62% during the first 1000 s. For close-to-neutral pH, where the particles are negatively charged, the fouling layers were thinner and less resistant to shear stress (290 ± 77 μm thick at a shear stress of 36 Pa) and the decline of the flux was faster: a 90% decrease was recorded during the initial 1000 s. The differences in flux decline behaviour suggest a more pronounced blocking of the pore openings for the membranes at the higher pH. Similar fouling behaviour was observed for the two membranes. An atomic force microscope equipped with a colloid probe was used to evaluate particle/particle and particle/membrane interactions.
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| 45. |
- da Cruz Francisco, José
(författare)
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On the Extraction of Essential Oils by Supercritical Carbon Dioxide and its Influence on the Mesomorphic Phase Structures
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A comparison of essential oils from leaves of Eucalyptus camaldulensis Dehn. obtained by hydrodistillation (HD) and supercritical carbon dioxide (SC-CO2) extraction is presented. Selected major components of the oils showed a predominance of higher molecular weight components in the SC-CO2 extracts than in those obtained by HD. Physico chemical properties such as molecular weight, vapour pressure of the components, steric factor as well as in oil composition. Discussions on environmental effects on the quality of the essential oils obtained on the same eucalyptus genotype treated by the same techniques are also presented. The monoterpenes 1,8-cineole, limonene and a-pinene, present in considerable amounts in eucalyptus leaf oils, as well as their mixtures and three eucalyptus oils from different genotypes, namely E. dives, E. polybractea and E. radiata, were also studied with regard to their solubility in dense CO2 (SC-CO2 and LCO2). In general, pure compounds showed a higher solubility in SC-CO2. The composition SC-CO2 at the highest pressure and temperature. Since polar lipids are always present in eucalyptus leaves from which the oil is extracted, the interaction between such lipids, water, SC-CO2 and essential oils is important to study. First, liquid crystalline properties and the extractability of monoolein/water systems by supercritical carbon dioxide are discussed. The most remarkable observation in this study was the loss of the native mesomorphic structure at high temperatures and the low recovery of monoolein in monoolein/water systems within the highest (18wt%) water content at temperatures between 35 and 65°C. These effects are explained by the SC-CO2, water and monoolein interactions which lead to different water and monoolein activities in the phase present. Further, two model systems composed of monoolein/water or soybean lecithin/water, cineole and SC-CO2 are presented for studying the phase behaviour. Generally, it is observed that the liquid crystalline structure remain also in presence of surplus of SC-CO2. Hence, it can be assumed that lipid structures in the plant tissues may remain also during SC-CO2 extraction and contribute to the matrix effects observed in extraction trials.
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| 46. |
- Innings, Fredrik, et al.
(författare)
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Dynamic modelling of the deformation of a drop in a four-roll mill
- 2005
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Ingår i: Chemical Engineering Science. - : Elsevier BV. - 0009-2509 .- 1873-4405. ; 60:17, s. 4771-4779
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Tidskriftsartikel (refereegranskat)abstract
- The deformation of a drop flowing along the centre streamline of a four-roll mill (4RM) has been investigated. The velocities and elongation rates along the centre streamline in the 4RM were measured using particle tracking velocimetry. The deformation and position of the deforming drops were photographed with a video camera. A dynamic, one-dimensional, analytical simulation model describing the drop deformation has been developed. The model is based on Taylor's [1964. International Congress on Applied Mechanics, vol. 11, 790-796] static conical drop shape model, but has been extended to include elliptic drops undergoing rapid deformation. The model was incorporated into a numerical scheme using Matlab and the drop deformation in the 4RM was simulated. The simulations were compared with the results of the experiments with the help of a dynamic Weber number incorporating the exact effect of the continuous phase stress on the deformation of the drop. With a dynamic Weber number of 0.42 the agreement between the experiments and the simulations along the whole deformation process was excellent for all three drop diameters studied. With this model the deformation of drops of all sizes in different elongation fields can be calculated, for example sub-micron-sized drops in a high-pressure homogeniser. (c) 2005 Elsevier Ltd. All rights reserved.
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| 47. |
- Papargyropoulou, Effie, et al.
(författare)
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Patterns and causes of food waste in the hospitality and food service sector : Food waste prevention insights from Malaysia
- 2019
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 11:21
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Food waste has formidable detrimental impacts on food security, the environment, and the economy, which makes it a global challenge that requires urgent attention. This study investigates the patterns and causes of food waste generation in the hospitality and food service sector, with the aim of identifying the most promising food waste prevention measures. It presents a comparative analysis of five case studies from the hospitality and food service (HaFS) sector in Malaysia and uses a mixed-methods approach. This paper provides new empirical evidence to highlight the significant opportunity and scope for food waste reduction in the HaFS sector. The findings suggest that the scale of the problem is even bigger than previously thought. Nearly a third of all food was wasted in the case studies presented, and almost half of it was avoidable. Preparation waste was the largest fraction, followed by buffet leftover and then customer plate waste. Food waste represented an economic loss equal to 23% of the value of the food purchased. Causes of food waste generation included the restaurants’ operating procedures and policies, and the social practices related to food consumption. Therefore, food waste prevention strategies should be twofold, tackling both the way the hospitality and food service sector outlets operate and organise themselves, and the customers’ social practices related to food consumption.
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| 48. |
- Roos, H, et al.
(författare)
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Evaluation of new methods and measuring systems for characterisation of flow behaviour of complex foods
- 2006
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Ingår i: Applied Rheology. - 1430-6395. ; 16:1, s. 19-25
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Tidskriftsartikel (refereegranskat)abstract
- Conventional methods often impose difficulties when measuring the viscosity of fluids containing particles or fibres, e.g. tomato paste or fruit preparations, mainly due to the narrow gaps of the viscometer. In order to solve these problems different geometries have been developed, e.g. different mixer systems and wide gap double concentric cylinders. However, these can not be evaluated assuming a constant shear rate throughout the fluid. In this study, three different kinds of mixer systems have been studied; a small and a large paddle and a helix. For the mixer systems an average shear rate must be determined and a quotient between torque and shear stress must be found. in addition, a wide gap double concentric cylinder (DCC) was examined and evaluated using two different methods. When evaluating the mixer systems a method based on the Couette analogy has been used successfully for a number of complex fluids, including prepared sauces and fruit samples containing particles of different size. The DCC has been evaluated using a numerical as well as an approximate method, both giving results of good accuracy. All systems had the limitation that no consistent results were obtained for tomato paste. However, when starch was added to the diluted tomato paste dispersion, satisfying results were once again obtained.
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| 49. |
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| 50. |
- Bohné, Ulrica, et al.
(författare)
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The EcoPanel: Designing for reflection on greener grocery shopping practices
- 2015
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Ingår i: PROCEEDINGS OF ENVIROINFO AND ICT FOR SUSTAINABILITY 2015. - : Atlantis Press. - 9789462520929 ; , s. 221-228
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Konferensbidrag (refereegranskat)abstract
- While the purchases of organic food are increasing rapidly, it accounts for only a small fraction of the total consumption, and there is still a big gap between consumer values awareness and the actual consumption. This article explores how detailed personal feedback could help the households to gain insight and reflect on their consumption, the text presents the design process of developing a prototype, the EcoPanel, in collaboration with a major player on the food retail market. Based on the access to detailed tracking of purchase data, the aim of the design was to provide relevant feedback to facilitate for reflection on the user's own food choices. The design prototype is intended to serve as an instrument for insight and reflection and to bring unconscious aspects of grocery shopping to conscious awareness. Following a research through design approach, this article describes the interdependent steps in designing the EcoPanel and design decisions playing a role for users' critical reflection of their food choice practices. It discusses the intention of each module in providing insight. Finally, we discuss how a social practice perspective may be useful for identifying fruitful future research into the design for more sustainable grocery shopping practices
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