W.M. Waites and J.L. Peel
In the traditional canning process the food is heated in its can and the heat treatment, typically 120°C for 20 minutes, is sufficient to sterilise both contents and container…
Abstract
In the traditional canning process the food is heated in its can and the heat treatment, typically 120°C for 20 minutes, is sufficient to sterilise both contents and container. This relatively severe heat treatment has practical disadvantages and in recent years an alternative treatment known as UHT (ultra‐high temperature) processing, has been introduced. The foodstuff, usually a liquid, is heated to a higher temperature for a very much shorter time — 140°C for 5 seconds is typical — usually in a continuous operation. The containers are sterilised separately before filling aseptically with the heat‐processed food. Containers for UHT products are made from plastics (chiefly polypropylene), paper board, aluminium foil or from laminates or other combinations of these materials.
Will M. Waites, Christine E.R. Dodd and Kathy J. Bolton
The problems produced by changes in agricultural and foodmanufacturing practices, which have resulted in increases in reportedcases of food‐borne illness, are discussed in…
Abstract
The problems produced by changes in agricultural and food manufacturing practices, which have resulted in increases in reported cases of food‐borne illness, are discussed in relation to Salmonella, Campylobacter jejuni, Clostridium botulinum, Aeromonas hydrophila, Listeria monocytogenes and Yersinia enterocolitica. Those areas where further research is urgently required in order to understand and reduce food‐borne microbial illness are examined, and solutions proposed.
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Gino Cortellessa, Fausto Arpino, Simona Di Fraia and Mauro Scungio
In this work, a new two-phase version of the finite element-based Artificial Compressibility (AC) Characteristic-Based Split (CBS) algorithm is developed and applied for the first…
Abstract
Purpose
In this work, a new two-phase version of the finite element-based Artificial Compressibility (AC) Characteristic-Based Split (CBS) algorithm is developed and applied for the first time to heat and mass transfer phenomena in porous media with associated phase change. The purpose of this study is to provide an alternative for the theoretical analysis and numerical simulation of multiphase transport phenomena in porous media. Traditionally, the more complex Separate Flow Model was used in which the vapour and liquid phases were considered as distinct fluids and mathematically described by the conservation laws for each phase separately, resulting in a large number of governing equations.
Design/methodology/approach
Even though the adopted mathematical model presents analogies with the conventional multicomponent mixture flow model, it is characterized by a considerable reduction in the number of the differential equations for the primary variables. The fixed-grid numerical formulation can be applied to the resolution of general problems that may simultaneously include a superheated vapour region, a two-phase zone and a sub-cooled liquid region in a single physical domain with irregular and moving phase interfaces in between. The local thermal non-equilibrium model is introduced to consider the heat exchange between fluid and solid within the porous matrix.
Findings
The numerical model is verified considering the transport phenomena in a homogenous and isotropic porous medium in which water is injected from one side and heated from the other side, where it leaves the computational domain in a superheated vapour state. Dominant forces are represented by capillary interactions and two-phase heat conduction. The obtained results have been compared with the numerical data available in the scientific literature.
Social implications
The present algorithm provides a powerful routine tool for the numerical modelling of complex two-phase transport processes in porous media.
Originality/value
For the first time, the stabilized AC-CBS scheme is applied to the resolution of compressible viscous flow transport in porous materials with associated phase change. A properly stabilized matrix inversion-free procedure employs an adaptive local time step that allows acceleration of the solution process even in the presence of large source terms and low diffusion coefficients values (near the phase change point).
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A recent Codex Alimentarius decision to refer the JointExpert Committee on Food Additives (JECFA) 1990 Revised Specificationfor gum arabic (Acacia senegal) for reconsideration has…
Abstract
A recent Codex Alimentarius decision to refer the Joint Expert Committee on Food Additives (JECFA) 1990 Revised Specification for gum arabic (Acacia senegal) for reconsideration has been made in response to trade interests despite concerned comments by consumer associations. Although the 1990 JECFA Specification remains in force the Codex recognises only the 1978 JECFA Specification, which pre‐dates the introduction of any microbiological requirement to ensure the absence of Salmonellae and Escherichia coli.
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Li Zhang, Bisheng Wu and Haitao Zhang
Natural gas hydrate (NGH) has been regarded as one of the most important resources due to NGH's large amounts of reserve. However, NGH development still faces many technical…
Abstract
Purpose
Natural gas hydrate (NGH) has been regarded as one of the most important resources due to NGH's large amounts of reserve. However, NGH development still faces many technical challenges, such as low production rate and reservoir instability resulting from NGH decomposition. Therefore, developing a fully coupled THMC model for simulating the hydrate decomposition and studying its mechanical behavior is very important and necessary. The purpose of this article is to develop and solve a multi-phase, strong nonlinearity and large-scale fully coupled thermal-hydro-mechanical–chemical (THMC) model for simulating the multi-physics processes involving solid-liquid-gas flow, heat transfer, NGH phase change and rock deformation during NGH decomposition.
Design/methodology/approach
In this paper, a multi-phase, strong nonlinearity and large-scale fully coupled THMC model is developed for simulating the multi-physics processes involving solid-liquid-gas flow, heat transfer, NGH phase change and rock deformation during NGH dissociation. The fully coupled THMC model is solved by using a fully implicit finite element method, in which the gas pressure, water pressure, temperature and displacement are taken as basic unknown variables. The proposed model is validated against with the experimental data, showing high accuracy and reliability.
Findings
A multi-phase, strong nonlinearity and large-scale fully coupled THMC model is developed for simulating the multi-physics processes involving solid-liquid-gas flow, heat transfer, NGH phase change and rock deformation during NGH decomposition. The proposed model is validated against with the experimental data, showing high accuracy and reliability.
Research limitations/implications
Some assumptions are made to make the model tractable, including (1) the composition gas of hydrate is pure methane; (2) the gas-liquid multi-phase flow in the pore obeys Darcy's law; (3) hydrate occurs on the surface of soil particles, both of them form the composite consolidation material; (4) the small-strain assumption is applied to composite solid materials, which are treated as skeletons and cannot be moved; (5) momentum change caused by phase change is not considered.
Practical implications
NGH has been regarded as one of the most important resources due to its large amounts of reserve. However, NGH development still faces many technical challenges, such as low production rate and reservoir instability resulting from NGH decomposition. Most of the existing studies decouple the process with solid deformation and seepage behavior, but the accuracy of the numerical results will be sacrificed to certain extent. Therefore, it is very important and necessary to develop a fully coupled THMC model for simulating the hydrate decomposition and studying its mechanical behavior.
Social implications
NGH, widely distributed in shallow seabed or permanent frozen region, has the characteristics of high energy density and high combustion efficiency (Yan et al., 2020). A total of around 7.5 × 1,018 m3 has been proved to exist around the world and 1 m3 of NGH can release about 160–180 m3 of natural gas (Kvenvolden and Lorenson) under normal conditions. Safely and sustainably extracting NGH commercially can effectively relieve global energy pressure and contribute to achieving carbon reduction goals.
Originality/value
The novelty of the present work lies in mainly two aspects. First, a fully coupled THMC model is developed for studying the multi-physics processes involving solid-liquid-gas flow, heat transfer, NGH phase change and solid deformation during NGH dissociation. Second, the numerical solution is obtained by using a fully implicit finite element method (FEM) and is validated against experimental data.
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Shelf‐life of cultured milk products is longer than milk but it is still limited. Shelf‐life of cultured milk products could be enhanced by adopting various techniques. The…
Abstract
Purpose
Shelf‐life of cultured milk products is longer than milk but it is still limited. Shelf‐life of cultured milk products could be enhanced by adopting various techniques. The purpose of this paper is to describe how the longer shelf‐life thus attained would extend the market reach and would be economically beneficial to both producers and consumers.
Design/methodology/approach
Attempt has been made to enlighten the various techniques such as bacteriocin (nisin, MicrogardTM, natamycin, etc.), lactoperoxidase‐thiocyanate‐hydrogen peroxide system (LP‐system), high pressure treatment, post‐production heat‐treatment (thermization, microwave heating), ultra‐violet (UV) irradiation, carbonization, etc.
Findings
Application of more than one bacteriocin may be advantageous to minimize the possibility of survival of microflora resistant to a particular bacteriocin. Pasteurization, being more detrimental to dietetic properties of cultured milk products than thermization, its application is not suggested as a method of preservation. Microwave heating may be better than conventional pasteurization.
Originality/value
Conjugated application of various techniques would be more efficacious in extending the shelf‐life of cultured milk products. Extension in shelf‐life of cultured milk products would be economically beneficial for producers and consumers.
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Alison Reid, Dawn Wood and David Kinney
The issues of microbial food poisoning are never far from the headlines. Of particular concern is the emergence of strains of increased virulence, for example Escherichia coli 0157…
Abstract
The issues of microbial food poisoning are never far from the headlines. Of particular concern is the emergence of strains of increased virulence, for example Escherichia coli 0157. As we are likely to be faced with a succession of food hygiene challenges in our kitchens, do consumers have access to the information they need and is it presented in such a way that it encourages and motivates towards good food handling and food hygiene practices? This paper concentrates on a range of food hygiene information provided by the Government, the Health Education Authority and the media. The information is examined with respect to availability, content and context. Observations are made from sociological, scientific and visual communications perspectives.
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The purpose of this study is to conduct a comprehensive and precise investigation into the influence of office environments on employee performance. Office workers spend a…
Abstract
Purpose
The purpose of this study is to conduct a comprehensive and precise investigation into the influence of office environments on employee performance. Office workers spend a considerable amount of time inside a building, and the office environment in which they work has a profound impact on their overall well-being and directly affects their effectiveness and productivity. Yet, the previous studies opted out the importance of hygiene factors like office environment and there is a need to uncover hidden causes and shed light on office environment areas that can be improved.
Design/methodology/approach
This research adopts a descriptive research design using a quantitative research method to study the relationships between office environment facilitations and employee performance. The technique of survey questionnaires was employed, and a total of 829 samples were analyzed. Measurement model, structural model and hypothesis testing using PLS-SEM software version 4.1.0.0 were briefly explained.
Findings
The study investigated the direct and indirect effects of the office environment on employee communication, interactions, productivity and performance. The findings revealed significant outcomes, indicating that the office environment does indeed have an impact on these employee-based factors. Both communication and interactions, as well as employee productivity as an indirect effect, were found to significantly mediate the connection between the office environment and employee performance.
Research limitations/implications
Insufficient data and analysis exist regarding the factors influencing the effect of employee performance on business. The constraints of time, cost and scope impede comprehensive surveys and thorough analysis. Regrettably, only four specific aspects of the office environment were examined in relation to employee performance, neglecting other significant factors. By acknowledging the potential problems highlighted in this study concerning different office concepts, organizations can endeavor to establish a more conducive working environment. It is imperative to acknowledge that the absence of a well-structured office environment that meets employees’ expectations may lead to unfavorable consequences.
Originality/value
To the best of the authors knowledge, this is the first study of office environment facilitations related to employee behavioral attitude and employee performance in Yangon, Myanmar and this study will help discover new insights of the importance of employee performance in least developing countries.
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Food and water safety is a major international concern. Among the food groups implicated with greater frequency in recent years as having caused or been associated with enteric…
Abstract
Purpose
Food and water safety is a major international concern. Among the food groups implicated with greater frequency in recent years as having caused or been associated with enteric diseases in humans are raw fruits and vegetables. Outbreaks of diseases caused by infectious and toxigenic bacteria as well as parasites and viruses have been documented to occur as a result of consumption of contaminated produce. This paper seeks to review the scientific literature reporting evidence to support the potential for preharvest contamination of fruits and vegetables intended to be eaten raw.
Design/methodology/approach
Sources of preharvest contamination of produce include manure, manure compost, sewage sludge, irrigation water, runoff water from livestock operations, and wild and domestic animals. Literature was reviewed to assess the conditions affecting survival of pathogenic microorganisms originating from these sources in preharvest environments and potential for contamination of produce before or at the time of harvest.
Findings
Prevention of preharvest contamination is essential to minimizing the risk of illness caused by consuming raw produce because postharvest treatment with sanitizers cannot be relied upon to eliminate pathogens.
Originality/value
A better understanding of the behaviour of pathogens in preharvest environments will enhance the prospect of developing effective strategies and interventions that will assure the delivery of safe produce to the consumer.
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Argues that the general area of commercial sponsorship activity, while attracting increasing interest from marketing practitioners as an important strategic option in marketing…
Abstract
Argues that the general area of commercial sponsorship activity, while attracting increasing interest from marketing practitioners as an important strategic option in marketing communications, has not been the subject of sufficiently rigorous and comprehensive investigation by theoreticians. States the purpose is to establish and consolidate the available body of knowledge combining an overview of the standard conceptual approaches to marketing communication with an examination of the recent academic research in sponsorship, while maintaining a focus on current marketplace practice. Argues for a coherent and structured approach to the management of sponsorship expenditure through the application of a ‘management by objectives’ approach. Parameters are established in terms of a working definition of sponsorship, a review of its commercial development and an overview of current activity. Develops a commercially ration framework within which sponsorship activity may be undertaken. Views objective‐setting as the cornerstone of sponsorship management and outlines a classification of sponsorship objectives that subsumes current practice clarifies the range of potential benefits. Examines the criteria that govern rational sponsorship selection and proposes an evaluation strategy based on stated criteria. Methods of evaluating effects of marketing communications (sponsorship particularly) are examined and new evaluation techniques are advanced to facilitate the implementation of this rigorous scientific approach.