2,236 research outputs found

    Residential home heating: The potential for air source heat pump technologies as an alternative to solid and liquid fuels

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    AbstractInternational commitments on greenhouse gases, renewables and air quality warrant consideration of alternative residential heating technologies. The residential sector in Ireland accounts for approximately 25% of primary energy demand with roughly half of primary home heating fuelled by oil and 11% by solid fuels. Displacing oil and solid fuel usage with air source heat pump (ASHP) technology could offer household cost savings, reductions in emissions, and reduced health impacts. An economic analysis estimates that 60% of homes using oil, have the potential to deliver savings in the region of €600 per annum when considering both running and annualised capital costs. Scenario analysis estimates that a grant of €2400 could increase the potential market uptake of oil users by up to 17% points, whilst a higher oil price, similar to 2013, could further increase uptake from heating oil users by 24% points. Under a combined oil-price and grant scenario, CO2 emissions reduce by over 4 million tonnes per annum and residential PM2.5 and NOX emissions from oil and peat reduce close to zero. Corresponding health and environmental benefits are estimated in the region of €100m per annum. Sensitivity analyses are presented assessing the impact of alternate discount rates and technology performance. This research confirms the potential for ASHP technology and identifies and informs policy design considerations with regard to oil price trends, access to capital, targeting of grants, and addressing transactions costs

    Interactions of vegetable proteins with other polymers: Structure-function relationships and applications in the food industry

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    peer-reviewedBackground In recent years, there has been increasing interest in vegetable proteins, due to their various health beneficial functions and wide applications in the food industry. Vegetable proteins combined with other edible polymers can be used to improve the quality and nutritional value of food products. In these complex food systems, interactions between different components are inevitable, and these interactions have a significant influence on the structure and functions of food products. Scope and approach This study reviews the current status of knowledge of interactions between vegetable proteins and other polymers (proteins or polysaccharides) in food systems and the structure of complexes formed by these interactions. The study also provides a comprehensive review of the applications of the complexes. Key findings and conclusions Vegetable proteins display different types of interactions with other polymers (e.g., polysaccharides, or animal proteins) under different conditions, thus forming a variety of complexes with different structures (e.g., double networks, mosaic textures and cross-linked structures), which showed different impact on properties of the final food products and their applications (e.g., substitution for fat, or encapsulation for bioactive ingredients) in the food industry. However, previous studies mainly focused on leguminous proteins and vegetable-protein-based mixtures of two polymers, further studies on other vegetable proteins and more complex food systems containing vegetable proteins and other polymers are required

    Bioaccessibility and Cellular Uptake of β-Carotene Encapsulated in Model O/W Emulsions: Influence of Initial Droplet Size and Emulsifiers

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    peer-reviewedThe effects of the initial emulsion structure (droplet size and emulsifier) on the properties of β-carotene-loaded emulsions and the bioavailability of β-carotene after passing through simulated gastrointestinal tract (GIT) digestion were investigated. Exposure to GIT significantly changed the droplet size, surface charge and composition of all emulsions, and these changes were dependent on their initial droplet size and the emulsifiers used. Whey protein isolate (WPI)-stabilized emulsion showed the highest β-carotene bioaccessibility, while sodium caseinate (SCN)-stabilized emulsion showed the highest cellular uptake of β-carotene. The bioavailability of emulsion-encapsulated β-carotene based on the results of bioaccessibility and cellular uptake showed the same order with the results of cellular uptake being SCN > TW80 > WPI. An inconsistency between the results of bioaccessibility and bioavailability was observed, indicating that the cellular uptake assay is necessary for a reliable evaluation of the bioavailability of emulsion-encapsulated compounds. The findings in this study contribute to a better understanding of the correlation between emulsion structure and the digestive fate of emulsion-encapsulated nutrients, which make it possible to achieve controlled or potential targeted delivery of nutrients by designing the structure of emulsion-based carriers

    Emulsion-based encapsulation and delivery systems for polyphenols

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    Background: Instability and low bioavailability of polyphenols greatly limit their potential health benefits in preventing ageing, cancer, inflammation and neurodegenerative diseases. Utilization of protected encapsulation and delivery system can improve the stability and bioavailability of polyphenols. A wide range of technologies have been developed to encapsulate polyphenols. Among these, emulsion-encapsulation is regarded as one of the most promising techniques for protection and delivery of polyphenols, due to its high-efficiency encapsulation, maintenance of chemical stability and controlled release. Scope and approach: In this review, preparation, applications and limitations of emulsion-based encapsulation and delivery systems for polyphenols, including single, multiple and nano-emulsions, are discussed. Key findings and conclusions. Utilization of encapsulated polyphenols instead of free molecules improves both the stability and bioavailability of the molecules in vitro and in vivo. Many emulsion-based delivery systems for polyphenols have been well established, including single, multiple and nano-emulsions. However, variations in composition and preparation technologies result in the formation of a range of emulsions of new properties with great potential in delivery of polyphenols or other bioactive nutrients, e.g., using unsaturated fatty acids as the oil phase, which can achieve the delivery of multiple nutrients at the same time. Furthermore, very few studies have been done on the in vivo absorption, transportation and release of polyphenols incorporated emulsions, which are essential to their deeper and wider applications. Hence, systematic and intensive investigation of metabolism and physiological effects of encapsulated polyphenols or other potential bioactive nutrients in vivo are required

    Preparation, structure-property relationships and applications of different emulsion gels: Bulk emulsion gels, emulsion gel particles, and fluid emulsion gels

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    peer-reviewedBackground In recent years, there has been increasing interest in emulsion gels, due to their better stability during storage and potential for prolonged intestinal drug release compared to emulsions. There are three kinds of emulsion gels, classified according to their morphological properties: bulk emulsion gels, emulsion gel particles and liquid emulsion gels. Scope and approach This paper provides a comprehensive review of the mechanisms and procedures of different methods for preparing different emulsion gels and relationships between structures and properties of emulsion gels. The applications of emulsion gels in the food industry are finally discussed. Key findings and conclusions Different emulsion gels result from different preparation methods, and have various structure-property relationships and applications. Many methods can be used to prepare bulk emulsion gels, involving different matrix materials, processing techniques, and purposes. This can result in different structures of gel matrices and emulsion droplets, and interactions between them, which can influence the structures of bulk emulsion gels and then their mechanical and release properties. On the other hand, extrusion and impinging aerosol methods are two methods for preparing emulsion gel particles, while liquid emulsion gels can be prepared by Pickering emulsions and disrupted gel systems. Rheological, syneresis and swelling properties are critical for gel particle suspensions, while flow behavior and release properties are important to liquid emulsion gels. In addition, fat replacements and delivery systems are main applications of emulsion gels in the food industry. However, current research has mainly focused on bulk emulsion gels, so further studies on emulsion gel particles and liquid emulsion gels are required.China Scholarship Counci

    Fabrication and characterization of highly re-dispersible dry emulsions

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    peer-reviewedHighly re-dispersible dry emulsions were obtained through drying konjac glucomannan (KGM) or monoglyceride (MG) structured O/W emulsions. Emulsion powders showed different morphologies, particle size and surface microstructures, depending on the drying method (spray/freeze-drying), and the emulsion compositions. The introduction of a low level of KGM (0.15 wt%) and MG (1 wt%) significantly reduced the level of maltodextrin as wall material. All powdered emulsions showed rapid re-hydration in water. Compared with original emulsions before drying, re-constituted emulsions from spray-dried powders showed slightly increased mean droplet size while that from freeze-dried ones showed slightly decreased mean droplet size. KGM significantly decreased the initial viscosity (p 93% in average). The findings in this study make it possible to obtain emulsion powders and their reconstitutions with desired properties by structuring the original emulsions before drying, and confirmed the possibility of KGM and MG in producing low-cost emulsion powders and the potential of these dry emulsions as novel solid delivery carriers for lipophilic components.Teagasc-The Irish Agriculture and Food Development Authorit

    Effect of concentrations of alginate, soy protein isolate and sunflower oil on water loss, shrinkage, elastic and structural properties of alginate-based emulsion gel beads during gelation

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    peer-reviewedThe aim of this study was to investigate the influence of concentrations of sodium alginate (0.5%–1.5% in the water phase of an emulsion), soy protein isolate (SPI, 0.5%–2.0% in the water phase) and oil phase (10%–40% in the emulsion) on the properties (including water loss, shrinkage, morphological, elastic, and structural properties) of emulsion gel beads during gelation (0–30 min). Gel beads were prepared with external gelation by dropping emulsions into CaCl2 solutions using pipettes. The Young's modulus of emulsion gel beads kept increasing during gelation before reaching a plateau accompanied by syneresis (i.e., water loss), shrinkage, and structural tightening. SPI absorbed at the surface of oil droplets could prevent re-coalescence of droplets during gelation. Additionally, increasing concentrations of sodium alginate and oil increased the Young's modulus of gel beads. Water loss decreased with increasing contents of alginate, SPI and oil, and shrinkage could be diminished by increasing alginate and oil contents.China Scholarship Counci

    Fabrication of Localized Surface Plasmon Resonance Fiber Probes Using Ionic Self-Assembled Gold Nanoparticles

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    An nm-thickness composite gold thin film consisting of gold nanoparticles and polyelectrolytes is fabricated through ionic self-assembled multilayers (ISAM) technique and is deposited on end-faces of optical fibers to construct localized surface plasmon resonance (LSPR) fiber probes. We demonstrate that the LSPR spectrum induced by ISAM gold films can be fine-tuned through the ISAM procedure. We investigate variations of reflection spectra of the probe with respect to the layer-by-layer adsorption of ISAMs onto end-faces of fibers, and study the spectral variation mechanism. Finally, we demonstrated using this fiber probe to detect the biotin-streptavidin bioconjugate pair. ISAM adsorbed on optical fibers potentially provides a simple, fast, robust, and low-cost, platform for LSPR biosensing applications
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