Food Refrigeration Research Articles

The FRISBEE tool, a software for optimising the trade-off between food quality, energy use, and global warming impact of cold chains

Food quality (including safety) along the cold chain, energy use and global warming impact of refrigeration systems are three key aspects in assessing cold chain sustainability. In this paper, we present the framework of a dedicated software, the FRISBEE tool, for optimising quality of refrigerated food, energy use and the global warming impact of refrigeration technologies. The food quality models implemented in the FRISBEE tool are based on validated kinetic models, most of which are available as separate publications in this issue, while the models for calculating energy use and global warming impact have been validated using independent data. The software was developed within the framework of the European Union FP7 project, FRISBEE (Food Refrigeration Innovations for Safety, consumers’ Benefit, Environmental impact and Energy optimisation along the cold chain in Europe). The consumers’ version of the FRISBEE tool, with limited functionalities, will be made available as free downloadable software on the FRISBEE website, while the version with full functionalities will be used for consultancy.

Electrospun heat management polymeric materials of interest in food refrigeration and packaging

ABSTRACTThe use of latent heat storage materials using phase change materials (PCMs) is an effective way of buffering thermal fluctuations and has the advantages of high‐energy storage density and the isothermal nature of the storage process. The aim of this work was to develop slabs with energy storage capacity for their application in refrigerated foods. To this end, polycaprolactone (PCL) and polystyrene (PS) were used as encapsulating matrices of a PCM, specifically RT5 (a paraffin which has a transition temperature at 5°C), by using electrohydrodynamic processing. The effect of storage temperature (4°C and 25°C) and time on the morphology and thermal characteristics of the PCL/RT5 and PS/RT5 slabs was evaluated. Results showed that RT5 can be properly encapsulated inside both polymers, although PCL provided better encapsulation efficiency. Encapsulation efficiency was affected not only by the polymer matrix but also by storage time at 25°C. The greatest encapsulation efficiency (98.6%) and optimum heat management performance was achieved for PCL/PCM slabs stored at 4°C, corresponding to materials composed of ∼44 wt % of PCM (core material) and ∼56 wt % of the PCL shell material. These temperature buffering materials can be of great interest to preserve the quality of packaged foods and to increase efficiency and reduce energy consumption in refrigeration equipment. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40661.

Solar Driven Absorption Chiller for Medium Temperature Food Refrigeration, a Study for Application in Indonesia

Indonesia has abundant renewable energy resources. In 2005 this country, however, only consumed 0.38% renewable energy of the total energy consumption. Most of the energy sources of the country are from fossil fuels which result in high CO2 emissions. Solar energy systems would be as an option to reduce the CO2 emissions of this country. This paper studied the application of solar energy to provide cooling for medium temperature food refrigeration based on Indonesian weather conditions. The paper additionally analyzed the environmental impact relating to CO2 emissions, and investigated the economical aspect. CFD-Fluent software was applied on modeling the modification of the absorption chiller generator to enable it to operate with heat from solar radiation, while F-Chart and Microsoft Excel spreadsheet were used to analyze the solar system and the economical viability of the technology. The results showed that the optimum modification of the absorption chiller was to use a jacket for heat addition. CFD modeling with Fluent using Diphyl THT as the heat transfer fluid (HTF) indicated that the system would function optimally at fluid temperature input of 180°C, whereas the optimum average temperature of the chiller generator would be 170 °C. The proposed technology was found economically less viable for food refrigeration compared to the vapor compression cycle using R-404A but it could provide a significant impact on the environment by a reduction of 37% CO2 emissions.

Screening for and surveillance of gastric cancer.

Although the prevalence of gastric cancer (GC) progressively decreased during the last decades, due to improved dietary habit, introduction of food refrigeration and recovered socio-economic level, it still accounts for 10% of the total cancer-related deaths. The best strategy to reduce the mortality for GC is to schedule appropriate screening and surveillance programs, that rises many relevant concerns taking into account its worldwide variability, natural history, diagnostic tools, therapeutic strategies, and cost-effectiveness. Intestinal-type, the most frequent GC histotype, develops through a multistep process triggered by Helicobacter pylori (H. pylori) and progressing from gastritis to atrophy, intestinal metaplasia (IM), and dysplasia. However, the majority of patients infected with H. pylori and carrying premalignant lesions do not develop GC. Therefore, it remains unclear who should be screened, when the screening should be started and how the screening should be performed. It seems reasonable that screening programs should target the general population in eastern countries, at high prevalence of GC and the high-risk subjects in western countries, at low prevalence of GC. As far as concern surveillance, currently, we are lacking of standardized international recommendations and many features have to be defined regarding the optimal diagnostic approach, the patients at higher risk, the best timing and the cost-effectiveness. Anyway, patients with corpus atrophic gastritis, extensive incomplete IM and dysplasia should enter a surveillance program. At present, screening and surveillance programs need further studies to draw worldwide reliable recommendations and evaluate the impact on mortality for GC.

Control optimizations for heat recovery from CO2 refrigeration systems in supermarket

A modern supermarket energy control system has a concurrent need for electricity, food refrigeration and space heating or cooling. Approximately 10% of this energy is for conventional gas-powered heating. In recent years, the use of CO2 as a refrigerant in supermarket systems has received considerable attention due to its negligible contribution to direct greenhouse gas emissions and excellent thermophysical and heat transfer properties. CO2 refrigeration systems also offer more compact component designs over a conventional HFC system and heat recovery potential from compressor discharge. In this paper, the heat recovery potential of an all-CO2 cascade refrigeration system in a supermarket has been investigated using the supermarket simulation model “SuperSim” developed by the authors. It has been shown that at UK weather conditions, the heat recovery potential of CO2 refrigeration systems can be increased by increasing the condenser/gas cooler pressure to the point where all the heat requirements are satisfied. However, the optimum level of heat recovery will vary during the year and the control system should be able to continuously optimize this level based on the relative cost of energy, i.e., gas and electricity.

Identified best environmental management practices to improve the energy performance of the retail trade sector in Europe

The retail trade sector has been identified as a target sector for the development of sectoral reference documents on best environmental management practices under the Eco-Management and Audit Scheme. This paper focuses on the important energy-related needs in retailers' stores such as for food refrigeration and lighting, as well as heating, ventilation and air conditioning of the building. For the definition of best environmental management practices in the European framework, frontrunner retailers have been identified as those retailers integrating energy minimization and saving measures as standard practice systematically across stores. These best performers also integrate a comprehensive monitoring system in the energy management of every store or building belonging to the company, enabling the rapid identification of energy saving opportunities. An integrative approach is needed to define how best practices should be implemented in combination to optimize energy management within stores: building aspects such as insulation of the building envelope or the heating, ventilation and air conditioning system, should be optimized in combination with best options for refrigeration in food retailers. Refrigeration systems are responsible for half of the final energy use in stores and of their carbon footprint. Natural refrigerants, heat recovery from the condensation stage and covering of display cases are measures with high environmental benefits to reduce the impact of refrigeration. Finally, practices for lighting, as optimal lighting strategies, and the integration of renewable energy sources in overall zero energy building concepts can save considerable amounts of fossil energy, reduce the carbon footprint and produce significant cost-savings in the long term.

HEAT TRANSFER AND EXTERNAL QUALITY ATTRIBUTES OF 'REGAL SEEDLESS' TABLE GRAPES INSIDE MULTI LAYERED PACKAGING DURING POSTHARVEST COOLING AND STORAGE

Postharvest packaging of table grapes is characterized by multi-layer packaging comprising of the carton box, the inner liner film, the individual bunch carry-bag and the SO2 sheet. This multi-layered packaging is required to allow sufficient airflow to efficiently cool packed grapes in order to preserve quality. Total pressure drop and cooling rates of different table grape packaging systems were measured and the percentage contributions of each package component and the fruit bulk were determined. Also, the effects of different carton liners on the cooling rate and external quality attributes of table grapes were investigated. Fruit quality attributes measured included stem dehydration and browning, SO2 injury and decay. On average the liner films contributed significantly higher to total pressure drop (61.04±15.91 %) than other components of the package combinations. Compared with the cooling of bulk grape bunches, the presence of the bunch carry bag increased the half and seven-eighth cooling time by 61.1 % and 97.3 %, respectively. The addition of plastic liners over the bunch carry bag increased the half and seven-eighth cooling time by 168.9 % and 185.2 %, respectively. Non-perforated liners maintained relative humidity (RH) close to 100 % during cold storage and during a 7-day shelf-life period which resulted in delaying the loss of stem quality but significantly (P  0.05) while increasing the incidence of SO2 injury and berry drop during storage compared with perforated liners. INTRODUCTION In most fresh food refrigeration systems, heat is transferred primarily by forced convection, where cold air is forced through food packages; therefore, the temperature and its homogeneity is largely governed by the patterns of the airflow (Smale et al., 2006; Zou et al., 2006). Table grapes are non-climacteric fruit and therefore should be harvested when reaching optimum maturity (Ginsburg et al., 1978; Hardenburg et al., 1986). However, fruit quality tends to deteriorate rapidly during postharvest handling and storage, thus reducing shelf-life during marketing. Deterioration of table grape quality is mainly characterised by stem (rachis) dehydration and browning, fruit weight loss and colour change, accelerated berry softening, berry shatter and high incidence of berry decay due mainly to Botrytis cineria. Table grapes are packed in multi-layered packaging which includes the carton boxes with multiple inner-packaging materials including carton liner films, SO2 pads, moisture absorption sheets and bunch carry bags (Ngcobo et al., 2011). Resistance to airflow may even be higher during table grape cooling due to the fact that berry bunches are packed inside multi-layered packages. It is therefore important to understand the effects of packaging materials and produce on airflow in order to fully understand cooling patterns and moisture transfer properties for the design of efficient cooling systems. The aim of this experiment was to investigate the effects of multi-layered packaging on airflow and cooling patterns and on external quality attributes of table grapes during cooling and storage. MATERIALS AND METHODS

Design of Heat-Transfer Media Components for Retail Food Refrigeration

High levels of emissions of ozone-depleting substances and greenhouse gases from supermarkets around the world can be attributed to the leakage of hydrofluorocarbons (HFCs) and the generation of el...

Characterization and experimental investigation of phase change materials for chilled food refrigerated cabinet applications

There is increasing interest in using phase change materials (PCMs) to store energy within refrigeration equipment. The main purpose is to increase the thermal capacity of the equipment and maintain product temperature within safe limits during frequent door openings, on–off cycling of the compressor and mains power failure. This paper considers candidate phase change materials for application in chilled food refrigeration cabinets for product temperature range between 0°C and +5°C. The results showed that paraffin products exhibited negligible supercooling but have low latent heat compared to water based products which have higher latent heat but exhibit a greater degree of supercooling. The addition of appropriate quantities of nucleate agent (AgI) can reduce supercooling significantly, making water based products suitable for use as PCMs for cold storage in chilled food cabinets.

The Acoustic Enclosure Design of the Refrigeration Compressor

In this paper, in order to reduce the external radiation of food refrigeration compressors noise, the main noise frequency analysis based on the theoretical calculation and practical experiment is carried out and the acoustic enclosure design is conducted. Conventional sound-absorbing material adopts rock wool and glass wool which have poor environmental protection. In the design process the environmental friendly melamine cotton is chosen as the sound-absorbing material that has not ever been massively adopted. Whats more, with a consideration of ventilation and heat dissipation, acoustic enclosure interior is designed with muffler air duct and the low-speed and low-noise fan. Therefore, both the normal operation of the compressor and the sound insulation of the acoustic enclosure are ensured in this way. Then with the sound level meter the noise A-weighted SPLs of the compressor with and without the enclosure are measured and are compared with each other. The results show that after covering the acoustic enclosure the compressors noise is less than 60 dB, which meets the design requirements of noise control. Therefore, it is easy to conclude that the sound insulation of the acoustic enclosure reaches the design standards and the acoustic enclosure design is feasible.

Prediction and analysis of the seasonal performance of tri-generation and CO2 refrigeration systems in supermarkets

A modern supermarket energy control system has a concurrent need for electricity, space heating or cooling, and food refrigeration. The power supply to the supermarket is primarily from the national grid, where losses in efficiency are due to the processes of energy conversion and transmission. Combined heat and power (CHP) offers the potential to locally produce electrical power and heating which could save energy and reduce CO2 emissions in the long run. During the summer months, as the space heating requirement in a supermarket is relatively small, the energy efficiency of a CHP installation can be improved by using excess thermal energy to drive a sorption refrigeration system to provide space cooling or refrigeration. This process is also known as tri-generation. In recent years, the use of CO2 as a refrigerant in supermarkets has received considerable attention due to its negligible contribution to direct greenhouse gas emissions and excellent thermophysical and heat transfer properties. Consequently, the application of a tri-generation system in a supermarket with CO2 refrigeration merits further investigation.In this paper, to evaluate the performance of a tri-generation system in the supermarket, a previously tested 80kWe microturbine device was applied into an operational supermarket to generate power and provide space heating and cooling through exhaust heat. The performance evaluation and comparison for this tri-generation application is based on the prediction from an integrated model of supermarket energy control, cascade CO2 refrigeration and tri-generation systems. The results from this simulation demonstrate the feasibility of a tri-generation system in the supermarket and pave the way for further consideration towards designs in future.

Contamination of Household Refrigerators by Listeria Species in Ahvaz, Iran

Background: Listeria monocytogenes has been isolated from various foods and environments in temperate areas, tropical countries and different parts of Iran. The bacterium as a psychrotrophic organism is capable of growth at refrigeration temperatures. Objective: The current study was conducted to determine the incidence of Listeria spp. on the surfaces of domestic refrigerators in Ahvaz city as a tropic area, to provide insights in to true burden of, and the risks posed by the bacterium in domestic refrigeration systems. Materials and Methods: During December 2009 June 2010, 180 refrigerators located at student accommodations and private homes in Ahvaz, were sampled for the presence of Listeria spp. The temperature of each refrigerator was measured and owners were asked to fill out a questionnaire regarding the method of cleaning. All samples were tested by culture in Listeria enrichment broth (LEB), Oxford agar and PALCAM agar using standard methods. Suspected colonies were identified by biochemical tests. Results: L. monocytogenes was present in 1 domestic refrigerator out of the 180 investigated (0.5 %) and L. innocua was also isolated from 2 refrigerators (1.2%). It was demonstrated that a significant number of the investigated refrigerators were operating at a temperature that can compromise the safety of the foods stored inside them. Also, most owners used mixture of water and dishwasher and some of them used water alone to clean their refrigerators. Conclusions: Although the incidence of L. monocytogenes in domestic refrigerators in Ahvaz is low contamination of the stored food in refrigerator by the bacterium is still a concern. Two of the isolated Listeria were from student accommodations. It was found that most of the refrigerators used in student accommodations in comparison to private homes, were not cleaned in low frequency and had higher temperature.

Experimental Investigation on an Absorption Refrigerator Driven by Solar Cells

This experiment is to study an absorption refrigerator driven by solar cells. Hand-held or carried in vehicle can be powered by solar energy in places without power. In the evenings or rainy days, it is powered by storage battery, and it can be directly powered by alternating current (AC) power supply if available, and the storage battery can be charged full as a backup supply. The proposed system was tested by the alternation of solar irradiance 550 to 700 W/m2as solar energy and 500ml ambient temperature water as cooling load. After 160 minutes, the proposal refrigerator can maintain the temperature at 5–8°C, and the coefficient of performance (COP) of NH3-H2O absorption refrigeration system is about 0.25. Therefore, this system can be expected to be used in remote areas for refrigeration of food and beverages in outdoor activities in remote and desert areas or long-distance road transportation of food or low temperature refrigeration of vaccine to avoid the deterioration of the food or the vaccines.

Environment Protection by Using a Solar Thermo-Electric Refrigerator for Cooling

The food eaten by people in their daily life must be preserved in good conditions. Therefore and for a better environment protection, the classical refrigeration systems that use a refrigerant had been removed and a solar thermo-electric cooler based on alternative energy sources was adopted. The solar energy was used in order to produce electrical energy, while the thermo-electric energy was responsible for the thermal transfer between the cooling room and the TEC modules, significantly reducing the temperature of the cold room and food products, respectively. The operation of the solar refrigerator was observed during the time of cooling one kilogram of pork meat and one litre of milk. In the case of cooling meat, the minimum temperature achieved was 1.8 ºC, respective 0.2 ºC when refrigerating milk. Considering the food refrigeration rated optimum temperature (0-4 ºC), the analysis of the experimental results highlighted the possibility of preserving meat and liquids in proper conditions by using a solar thermo-electric refrigerator, which is an ecological equipment with the pollution rate extremely low, almost null.

Numerical Simulation of Noise Radiation from Semi-Hermetic Reciprocating Food Refrigeration Compressors

The semi-hermetic reciprocating compressor is the dominant noise source of food refrigeration unit. Excessive noise and vibration have a negative impact on both people's health and work efficiency；moreover, it causes fatigue damage to machinery thus reducing its working life. In this paper, numerical simulation of noise radiation from semi-hermetic reciprocating food refrigeration was carried out by successful combination of Pro/E, Hypermesh, Nastran and Virtual Lab Acoustics software. The simulation results show that the low-frequency noise radiation near the end of the piston-cylinder is directional and stronger than that of the other side, which offers a valuable reference for noise reduction. In addition, the sound pressure dB curve of any field point can be obtained through the numerical simulation, and it clearly shows that sound pressure values away from the piston end are significantly lower than those at the piston side; and noise radiation energy of compressor concentrates at 500Hz and 1000Hz. This paper provides an effective research method for the semi-hermetic reciprocating compressor’s noise reduction

A Harmonic Response Analysis of Food Refrigeration Compressor Based on Abaqus

A harmonic response analysis was conducted on semi-hermetic refrigeration compressor by Abaqus software. The vibration displacement and acceleration response spectrums of the compressor’s key points were obtained. The vibration characteristics of the compressor show that the harmonic response analysis result is consistent with the experimental one. The vibration of the compressor at 50Hz is the most dramatic. The first trough in each direction is found around 70Hz, and after that each direction’s acceleration goes up significantly. At the same time, the conclusion verifies the vibration of compressor’s bottom corners by LMS Test. Lab Signature Testing. The paper provides a scientific reference for the further study on vibration and noise reduction in food refrigeration compressors.

Ice!: The Amazing History of the Ice Business (review)

Reviewed by: Ice!: The Amazing History of the Ice Business Elizabeth Bush Pringle, Laurence . Ice!: The Amazing History of the Ice Business. Calkins Creek, 2012. 74p. illus. with photographs ISBN 978-1-59078-801-1 $17.95 R Gr. 5-9. Sometimes the unlikeliest topics prove unexpectedly fascinating. Kids who embrace that truism will want to take a look at this slice of American commercial history that examines how people coped before the days of electric food refrigeration, and how a population that became hooked on cool drinks, ice cream, and convenience demanded a commodity that Nature alone couldn't fully supply. The focus here is on Rockland Lake in New York state, the first large-scale supplier of ice to a massive urban area. Science and engineering shake hands with geography and history in the details of how water freezes and melts; how the tools of ice harvesting were developed; how harvested ice was transported over hills and down rivers in a relatively low-tech environment; how ice was priced and distributed to an ever more dependent populace; and how high demand following a mild winter or a local fire could result in riots. Sidebar information and period illustrations are engrossing, from the 1862 ad for Bunn's Corpse Preserver, to the 1901 Cochichewick Lake Ice Company schedule of prices that allows modern readers to calculate the best delivery deal. A bibliography and index will assist students who would like to develop [End Page 165] this topic into a research project, but most readers will be content to thank their stars that the ice in their soft drink didn't have to be scraped clean of horse urine on the way to the glass. Copyright © 2012 The Board of Trustees of the University of Illinois

The Prospects of Alternatives to Vapor Compression Technology for Space Cooling and Food Refrigeration Applications

The Prospects of Alternatives to Vapor Compression Technology for Space Cooling and Food Refrigeration Applications

Carbon dioxide refrigeration with heat recovery for supermarkets

This paper describes the outcomes of a research project that investigates sustainable heating and cooling solutions for retail applications using a carbon dioxide (CO2) natural refrigerant (R744) for food refrigeration. The paper presents the findings from an applied research study on a booster CO2 (R744) system with high and medium temperature heat recovery. The paper includes a description of the conceptual design and a computer model along with its validation based on some experimental results. The energy consumption and carbon emission reduction are investigated using this novel system based on an existing supermarket as a case study. This is the version of record

Status of not-in-kind refrigeration technologies for household space conditioning, water heating and food refrigeration

This paper presents a review of the next generation not-in-kind technologies to replace conventional vapor compression refrigeration technology for household applications. Such technologies are sought to provide energy savings or other environmental benefits for space conditioning, water heating and refrigeration for domestic use. These alternative technologies include: thermoacoustic refrigeration, thermoelectric refrigeration, thermotunneling, magnetic refrigeration, Stirling cycle refrigeration, pulse tube refrigeration, Malone cycle refrigeration, absorption refrigeration, adsorption refrigeration, and compressor driven metal hydride heat pumps. Furthermore, heat pump water heating and integrated heat pump systems are also discussed due to their significant energy saving potential for water heating and space conditioning in households. The paper provides a snapshot of the future R&D needs for each of the technologies along with the associated barriers. Both thermoelectric and magnetic technologies look relatively attractive due to recent developments in the materials and prototypes being manufactured.