Flexible Pouches Research Articles

Oxygen barrier and enthalpy of melting of multilayer EVOH films after pressure‐assisted thermal processing and during storage

AbstractPressure‐assisted thermal processing (PATP) is an advanced thermal process involving application of elevated pressures above 600 MPa on a preheated food for a holding time of 3 to 5 min, causing the volumetric temperature of food to increase above 100°C, to inactivate bacterial spores and enzymes. This study evaluated the influence of PATP on two state‐of‐the‐art multilayer EVOH films. Flexible pouches containing water as the food simulant were made from the two films and processed at 680 MPa for 3 min at 105°C and 680 MPa for 5 min at 100°C. Each film was investigated for its oxygen transmission rates (OTRs), melting temperature (Tm), enthalpy of melting (ΔH), and overall crystallinity before (control) and after processing. The changes in OTRs and total ΔH of the two films were also analyzed during a storage period of 240 days in ambient conditions after processing. Results showed a significant (P < 0.05) increase in the OTRs of the two films after PATP. However, PATP did not cause a significant (P > 0.05) change in the Tm and ΔH of the two films. The overall crystallinity of film A decreased, but improved slightly for film B after PATP. A recovery in the OTRs of the two films occurred during storage. The films also showed changes in the total ΔH measured during the storage period, which was used to explain the changes in the oxygen barrier properties. The OTR of both films remained below 2 cc/m2 day, which is required in packaging applications for shelf‐stable foods with a 1‐year shelf life. This work demonstrates the advantages of using multilayer films containing EVOH as the barrier layer in PATP applications to produce shelf‐stable foods. This work also highlights the advantage of, DSC analysis for studying the physical ageing of polymers during storage. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Measuring and Predicting Head Space Pressure during Retorting of Thermally Processed Foods

Traditional metal cans and glass jars have been the mainstay in thermally processed canned foods for more than a century, but are now sharing shelf space with increasingly popular flexible pouches and semi-rigid trays. These flexible packages lack the strength of metal cans and glass jars, and need greater control of external retort pressure during processing. Increasing internal package pressure without counter pressure causes volumetric expansion, putting excessive strain on package seals that may lead to serious container deformation and compromised seal integrity. The primary objective of this study was to measure internal pressure build-up within a rigid air-tight container (module) filled with various model food systems undergoing a retort process in which internal product temperature and pressure, along with external retort temperature and pressure, were measured and recorded at the same time. The pressure build-up in the module was compared with the external retort pressure to determine the pressure differential that would cause package distortion in the case of a flexible package system. The secondary objective was to develop mathematical models to predict these pressure profiles in response to known internal temperature and initial and boundary conditions for the case of the very simplest of model food systems (pure water and aqueous saline and sucrose solutions), followed by food systems of increasing compositional complexity (green beans in water and sweet peas in water). Results showed that error between measured and predicted pressures ranged from 2% to 4% for water, saline, and green beans, and 7% to 13% for sucrose solution and sweet peas. Flexible packages have limited strength, and need more accurate and closer control of retort pressure during processing. The package becomes more flexible as it heats and might expand with increasing internal pressure that may cause serious deformation or rupture if not properly controlled and/or counterbalanced with external retort pressure. This article describes methods for determining exactly what the retort pressure profile will need to be to avoid this problem during retorting, and mathematical models to predict these pressures in response to known internal temperature and initial/boundary conditions.

Combination of high frequency electromagnetic fields with pre heat to inactivate mesophil microorganisms of flexible packed cooked chick and cooked chick meal

The effect of high frequency Electromagnetic Induction (EMI) combined with various condition of pre-heating for inactivation of mesophil microorganisms in multilayer flexible pouches has been studied. All samples were filled in pouches and, have been put in (water bath chamber; different condition of pre heating (80°C 5 min, 80°C 10 min, 80°C 15 min, 85°C 5 min, 85°C 10 min, 85°C 15 min) have been done; and ready for EMI sterilization which discharges square-wave pulses with variable voltage 1-20 kV/cm and frequency 8-10 GHz. The spores of these bacteria (gr+) were practically resistant in electric field; however, pre heat caused spore changed its behavior from passive forms (latent) to active forms (vegetative). If cells are cultivated at higher temperature, increasing tendency which can permanently keep fluidity viscosity of the cell membrane before electromagnetic field so EMI efficiency is increased. The populations of mesophil microorganisms depended on type of treatment type of chick type and type of culture. The death ratio of mesophil microorganisms increasing in chick 14200% more than chick meal, chance of negative mesophile microorganism growth in every treatment compares with last treatment increasing 54%. Negative growth in culture PCA is 3.3 degree more than culture PE 2, in culture PE 2 is 330% more than culture Cook meat; how ere these parameter in various thermal processing without EMI was evaluated positive mesophile microorganism growth increasing in chick meal 1905% more than chick type, and chance of passive mesophile microorganism growth in every treatment compares with last treatment decreasing 41% and type culture have no effect on growth of mesophil bacteria. Key words: High frequency electromagnetic fields, electromagnetic induction, flexible packaging, mesophil bacteria, thermal processing, cooked chick, cooked chick meal.

Sterilization of flexible pouch by high frequency electromagnetic induction, using cooked chick and chick meal

The effect of high frequency electromagnetic induction (EMI) in combination with various pre-heating conditions on sterilization of multilayer flexible pouches was studied. All samples of cooked chick and cooked chick meal pouches were sterilized using EMI which discharges square-wave pulses with variable voltage of 1-20 kV/cm and with different frequencies of 2-4, 4-6, 6-8 and 8-10 GHz in step one. The effect of high frequency electromagnetic induction on Clostridium and Bacillus is not adequate because spores of these bacteria are practically resistant to electrical field. So pouches were put in water bath chamber with different pre-heating conditions (80°C for 5 min; 80°C for 10 min; 80°C for 15 min; 85°C for 5 min; 85°C for 10 min; 85°C for 15 min) combined with 8-10 GHz. If cells are cultivated at higher temperature, this increasing tendency can permanently keep the fluid of cell membrane viscous before electromagnetic field; thus, EMI efficiency is increased. The populations of mesophile microorganisms depended on culture or type of treatment and chick. The death ratio of mesophile microorganisms increases in chick by 14200% more than in chick meal, but in every condition, growth of thermopile microorganism has not been reported. However, the chances of passive mesophile microorganisms in various thermal processing without EMI and preheating was evaluated in chick meal as 190500,106700 percent more than that of the chick type while the chance of positive thermopile microorganism growth in various thermal processing without EMI and preheating decreases in chick meal by 76.22% more than that of chick. Key words: High frequency electromagnetic fields, electromagnetic induction, flexible packaging, mesophile bacteria, thermopile bacteria, thermal processing, cooked chick, cooked chick meal.

SHELF LIFE ENHANCEMENT OF COCONUT BURFI – AN INDIAN TRADITIONAL SWEET

ABSTRACT Coconut burfi is a popular traditional sweet of south India. The high percentage of saturated fat present in the product makes it susceptible to hydrolytic rancidity. The resulting increase in free fatty acid content coupled with mold growth limit its shelf life to 7–10 days in unpacked condition. Studies have been carried out on packaging and storage aspects of coconut burfi to extend its shelf life. The samples were packed in flexible pouches of multilayer films consisting of (1) polyester/polyethylene; and (2) polyester/aluminum foil/polypropylene under the following conditions: (1) normal packing; (2) 99% vacuum packaging; and (3) in‐package heat processing, and were stored at 27C temperature and 65% relative humidity and periodically withdrawn to monitor changes in chemical, microbiological and sensory qualities. A maximum of 75 days shelf life was obtained for heat‐processed samples as against <15 and 45 days for air and vacuum packed samples respectively in both packaging materials.PRACTICAL APPLICATIONSBy this study, the shelf life of coconut burfi has been extended to two and a half months, which enables to increase the marketability and sale of the product and make the nutritious product conveniently available for everybody.

An integrated, self-contained microfluidic cassette for isolation, amplification, and detection of nucleic acids

A self-contained, integrated, disposable, sample-to-answer, polycarbonate microfluidic cassette for nucleic acid-based detection of pathogens at the point of care was designed, constructed, and tested. The cassette comprises on-chip sample lysis, nucleic acid isolation, enzymatic amplification (polymerase chain reaction and, when needed, reverse transcription), amplicon labeling, and detection. On-chip pouches and valves facilitate fluid flow control. All the liquids and dry reagents needed for the various reactions are pre-stored in the cassette. The liquid reagents are stored in flexible pouches formed on the chip surface. Dry (RT-)PCR reagents are pre-stored in the thermal cycling, reaction chamber. The process operations include sample introduction; lysis of cells and viruses; solid-phase extraction, concentration, and purification of nucleic acids from the lysate; elution of the nucleic acids into a thermal cycling chamber and mixing with pre-stored (RT-)PCR dry reagents; thermal cycling; and detection. The PCR amplicons are labeled with digoxigenin and biotin and transmitted onto a lateral flow strip, where the target analytes bind to a test line consisting of immobilized avidin-D. The immobilized nucleic acids are labeled with up-converting phosphor (UCP) reporter particles. The operation of the cassette is automatically controlled by an analyzer that provides pouch and valve actuation with electrical motors and heating for the thermal cycling. The functionality of the device is demonstrated by detecting the presence of bacterial B.Cereus, viral armored RNA HIV, and HIV I virus in saliva samples. The cassette and actuator described here can be used to detect other diseases as well as the presence of bacterial and viral pathogens in the water supply and other fluids.

Thinking Outside of the Cereal Box: An Innovative Solution for Package Resealability

From Olympic champions to kidfriendly characters, countless cultural icons have graced American breakfast tables on cereal boxes for decades. The dominant packaging format—bag-inbox—has served its purpose for just as long. It’s easy to stack in a cabinet or stash in a desk drawer, but it does have pitfalls. As consumers increasingly hunt and criticize any seemingly excess packaging, the cereal box seems like obvious prey. And as the trend toward keeping products fresher longer to reduce food waste continues to take hold, trying unsuccessfully to tuck away the plastic bag inside a cereal box could become a distant memory. Certainly, a handful of consumer product goods (CPGs) companies have taken measures to reduce the packaging material used for their breakfast products or even introduce completely new formats; yet, walk down the cereal aisle at any local grocery store and bag-in-box remains the norm. According to a 2009 report from Hoover’s Inc., the U.S. cereal industry boasts annual revenue of more than $9 billion, but it remains highly concentrated with 80% generated by only four major manufacturers (2). Despite this industry dominance, it seems that smaller specialty brands and retailers are leading the way in innovative alternatives to the bag-in-box. The question constantly arises as to why resealable closures have not been implemented on numerous products, and cereal remains the most bewildering for packaging professionals and consumers alike. With new technologies and packaging solutions, however, the cereal aisle is long overdue for a material makeover. Resealable Pouches: The Breakfast of Sustainability Champions Reducing the amount of materials used in the manufacture of product packaging and minimizing the product-to-package ratio are among the most efficient ways to enhance the sustainability of a package. It seems counterintuitive, then, that bag-inbox cereal packaging has withstood the industry shift toward environmental friendliness. This is especially perplexing when considering that flexible pouches offer all of these sustainability benefits, while simultaneously providing the option for a convenient resealable closure. To bolster these sustainability claims, Zip-Pak, a global leader for resealable packaging solutions, based in Glenview, IL, U.S.A., recently commissioned an independent life cycle inventory to quantify the benefits of resealable flexible packaging compared to rigid alternatives. The study, conducted by Franklin Associates, Inc., confirmed that resealable flexible pouches had lower energy consumption, greenhouse gas emissions, and solid waste generation than bag-in-box cereal packaging (1). Specifically, the research found that a 20-ounce bag-in-box cereal package consumed 85% more energy, generated 3.5 times more waste, and 2 times more greenhouse gas than the 21-ounce flexible pouch doi:10.1094 / CFW-55-4-0184

EFFECT OF PACKAGING MATERIAL AND STORAGE CONDITIONS ON PHYSICOCHEMICAL, MICROBIAL AND ORGANOLEPTIC PROPERTIES OF BLACKCHERRY PRESERVES IN LAMINATED FLEXIBLE POUCHES

In this study, a flexible package comprises of three layers, polyethylene (100μ), aluminium foil (9μ) and polyester (12μ) was used for packaging blackcherry preserves. All packed preserves were kept up to three months at 4 different storage temperatures (4, 23, 35 and 40°C). Physicochemical, microbial and organoleptical properties of all trials were determined monthly. As a result, the average pH, °Bx, acidity, Fe and Pb content were 3.99, 17.49, 0.25, 3.16ppm and 387.98ppb. All organoleptical properties of samples were acceptable. Temperature had statistically significant effect on the physicochemical and organoleptical properties of samples. The samples stored at 4 and 23°c were more acceptable due to their better quality. Flexible pouches have more advantages such as good colour and constant level of heavy metal as well as low cost and.. Keywords: blackcherry, laminated flexible pouch, packaging, preserve

Physico-chemical characteristics, nutritional quality and shelf-life of pearl millet based extrusion cooked supplementary foods

The process variables for extrusion cooking of pearl millet were standardized and some of the physicochemical characteristics of the millet extrudates and also the nutritional qualities of the millet and legume-based extruded supplementary foods were determined. The millet grits less than 355 µm in size, equilibrated to 18±1% moisture content, extruded at 150±5°C temperature and at 200±10 rpm of the barrel of a twin-screw extruder yielded the extrudates of 1.75±0.21 expansion ratio and 7.5±1.5 kg breaking strength. The cold and cooked paste viscosity, the melt energy and also the carbohydrate digestibility of the extrudates indicated that the products were pre-cooked and were of ready-to-eat nature. The millet was blended with grain legumes (30%) and also with defatted soy (15%) separately and extruded to prepare ready-to-eat nutritious foods suitable as food supplements to children and mothers. The foods based on the millet and legumes and also the millet and soy contained 14.7% and 16.0% protein with 2.0 and 2.1 protein efficiency ratio values, respectively. The shelf-life of the foods was about 6 months in different flexible pouches at ambient storage conditions. The study showed that applications of extrusion cooking technology to pearl millet have promise for preparation of diversified and value-added food products from the millet.

Minimally processed potatoes: Part 2. Effects of high oxygen partial pressures in combination with ascorbic and citric acid on loss of some quality traits

Sliced potatoes were stored in flexible packaging under different oxygen partial pressures (10, 55 and 100 kPa) after dipping treatments with ascorbic and citric acid at different concentrations. The levels of oxygen, ascorbic and citric acid were modulated according to a Central Composite Design. The response surface methodology allowed an assessment of the effects of these variables and their interactions on the respiration rate in a closed system, on the carbon dioxide accumulation rate and the volatile metabolites production inside flexible pouches. The results showed that the respiration rate did not increase in direct linear proportion to the oxygen partial pressure and there was no significant difference in respiration between 55 and 100 kPa, even though the respiration rate was higher at these super-atmospheric oxygen levels than at 10 kPa. Citric acid did not affect the respiration significantly, while the respiration rate increased with the increase in ascorbic acid concentration. However, at the highest level of ascorbic acid tested (5%), the respiration rate decreased. During storage in a high barrier plastic pouch, a higher CO 2 accumulation rate was generally observed under 55 kPa than under 10 and 100 kPa. High oxygen partial pressures (55 and 100 kPa) did not stop the production of hexanal but they had an inhibitory effect on the anaerobic volatiles production.

Shelf life of minimally processed potatoes: Part 1. Effects of high oxygen partial pressures in combination with ascorbic and citric acids on enzymatic browning

The shelf life of minimally processed potatoes is limited by enzyme-catalysed browning reactions. Generally, this phenomenon is controlled by the use of chemical reagents such as ascorbic acid, citric acid, or 4-hexyl resorcinol, but it seems that “oxygen shock” treatments are also particularly effective in inhibiting enzymatic browning. The aim of this work was to study the effects of high oxygen partial pressures in combination with ascorbic and citric acid on the development of the enzymatic browning of peeled and cut potatoes (‘Primura’ variety) that were packaged in flexible pouches and stored at 5 °C for 10 days. Different treatments, chosen in according to a central composite design, were applied to the sliced potatoes. The browning development during storage was measured by a tristimulus colorimeter. Second-order polynomial models were computed for three periods of storage (3, 7 and 10 days) to relate the independent variables (oxygen partial pressure, ascorbic and citric acid concentrations) to the colour function attributes. The effectiveness of the statistical approach offered the possibility to investigate the effects of several processing conditions involved in the enzymatic browning of minimally processed potatoes, while the response surface methodology allowed the identification of the optimum range of the independent variables which prevented browning.

Modeling of Active Modified Atmosphere Packaging of Endives Exposed to Several Postharvest Temperatures

ABSTRACTEndives were sealed in low‐density polyethylene flexible pouches containing or not containing individual oxygen or carbon dioxide scavenger sachet and stored at 5 °C and 20 °C. A mathematical model has been applied to predict gas changes for these passive and active modified atmosphere packaging (MAP). The model took into account the respiration rate of endives, the transmission rate of gases through the film, the absorption kinetics of gas scavengers, and the temperature influence of all these parameters. Whatever the temperature, the model was successfully validated with root mean square error values still lower than 1 kPa and thus represented a real tool to improve the design of MAP for fresh fruits and vegetables. Oxygen scavengers reduced by half the transient period duration (50 h compared with 100 h without scavengers) and did not modify the gas equilibrium composition, suggesting a beneficial influence on keeping the quality of the product. The carbon dioxide scavengers’ influence was limited and needs further study with carbon dioxide‐sensitive products.

Recycling of Edible Oil Pouches: Composition and Thermal Stability

Recycled polyethylene containing very small amounts of nylon-6 or PET, which is the source of flexible oil pouches, may find applications as raw materials for other polymer products after the recycled polymer is properly identified and characterized before reprocessing. Proper identification and characterization of the polymer components present in the waste has considerable importance for obtaining value-added products. In this investigation, post-use oil pouch films, collected from municipal garbage, were first subjected to sorting, washing and drying. Then the dried films were fractionated by dissolving in solvents. The isolated component polymers were characterized and identified by solvent fractionation, FTIR, DSC-TGA and WAXD analysis.

SHELF‐LIFE STUDY OF RETORT POUCH BLACK BEAN AND RICE BURRITO COMBAT RATIONS PACKAGED AT SELECTED RESIDUAL GAS LEVELS

Abstract Black bean and rice burrito meal‐ready‐to‐eat individual‐size (MRE's) entrées were retorted in flexible pouches with four residual gas levels (10, 20, 30, 40 cm3) and stored at three temperatures (4.4, 26.7 and 37.8C). Storage temperature was more influential upon quality than residual gas beyond one month of storage. Physicochemical and trained sensory analyses demonstrated that burritos stored at 37.8C darkened over time, but burritos stored at 4.4 and 26.7C did not. Untrained consumers gave lower scores to burritos stored at 37.8C, which were dull, dark, dry, and compressed, than to burritos stored at 4.4C, which were glossy, light, sticky and moist throughout storage. Burrito shelf‐life exceeded 6 months at 4.4C, but was limited to less than 3 months at 37.8C. Residual gas levels in black bean and rice burrito MRE's need not be specified as long as levels are maintained between 10–40 cm3.

Comparative shelf life study and vitamin C loss kinetics in pasteurised and high pressure processed reconstituted orange juice

Shelf life of reconstituted orange juice after conventional thermal (80 °C, 30 s) or high hydrostatic pressure (500 MPa, 35 °C, 5 min) pasteurisation was comparatively studied. Polypropylene bottles and laminated flexible pouches were used. Ascorbic acid loss, colour, viscosity and sensory characteristics were measured during storage at 0–15 °C. Ascorbic acid degradation rates were lower for high pressurised juice, leading to an extension of its shelf life compared to conventionally pasteurised juice. Kinetic modelling established a higher temperature dependence of ascorbic acid loss for high pressurised juice as expressed by activation energy values (61.1 and 43.8 kJ/mol respectively for high pressurised and thermally treated bottled juice). Based on ascorbic acid retention, the increase of shelf life of high pressurised juice stored in bottles compared to thermally pasteurised one ranged from 11% (storage at 15 °C) to 65% (storage at 0 °C). Respective values of shelf life increase for juices in pouches were 24% and 57%. Colour was not substantially affected by type of processing. Higher viscosity values were determined for high pressurised juice, while its sensory characteristics were judged superior.

Traditional Kerala style fish curry in indigenous retort pouch

Fish curry processed in metal cans is popular in the overseas markets. An important limitation with the use of metal cans is the undesirable taste imparted to the products on storage. Flexible pouches are an ideal alternative to metal cans. Extensive work carried out at Central Institute of Fisheries Technology has been able to identify indigenous pouches, which are as good as imported pouches. This has been done after collecting different types of indigenous and imported flexible pouches, analyzing their composition and conducting detailed studies on their physical and food contact application properties. Two indigenous pouches with composition 12 micron polyester/ 12 micron aluminium foil/ 87.5 micron cast polypropylene and 12 micron polyester/ 15 micron aluminium foil/ 70 micron cast polypropylene have been selected and got made by indigenous laminators and an imported one with configuration 12 micron polyester/ 15 micron aluminium foil/ 75 micron cast polypropylene were used for further experiment on processing fish curry. Traditional Kerala style mackerel fish curry was processed in the retort pouches of the above configurations. About 220 g fish curry was packed in each pouch (15.5 cm×7 cm) . Process requirements were worked out by measuring heat penetration using thermocouples introduced into the pouches. Fish curry processed to a F 0 value of 8.43 gave an acceptable product with desired texture and sensory characteristics. The physical properties of the pouches studied showed that the indigenous pouches of the above configurations were good enough to give a shelf life of 1 year at room temperature. The curry remained sterile throughout the storage period at ambient temperature (25–30°C) and retained acceptable sensory characteristics.

Guidance for Improving Life‐Cycle Design and Management of Milk Packaging

SummaryLife‐cycle inventory and cost‐analysis tools applied to milk packaging offer guidelines for achieving better environmental design and management of these systems. Life‐cycle solid waste, energy, and costs were analyzed for seven systems including single‐use and refillable glass bottles, single‐use and refillable high‐density polyethylene (HDPE) bottles, paperboard gable‐top cartons, linear low‐density polyethylene (LLDPE) flexible pouches, and polycarbonate refillable bottles on a basis of 1,000 gal of milk delivered. In addition, performance requirements were also investigated that highlighted potential barriers and trade‐offs for environmentally preferable alternatives. Sensitivity analyses, indicated that material production energy, postconsumer solid waste, and empty container costs were key parameters for predicting life‐cycle burdens and costs. Recent trends in recycling rates, tipping fees, and recycled materials market value had minimal effect on the results. Inventory model results for life‐cycle solid waste and energy indicated the same rank order as results from previously published life‐cycle inventory studies of container systems.Refillable HDPE and polycarbonate, and the flexible pouch were identified as the most environmentally preferable with respect to life‐cycle energy and solid waste. The greater market penetration of these containers may be limited by performance issues such as empty container storage, handling requirements, and deposit fees for refillables, and resealability and puncture resistance for the pouch.

Postprocess Contamination of Flexible Pouches Challenged by In Situ Immersion Biotest

Packages were evaluated for leaks by determining microbial penetration through microchannels as a function of test organism concentration, location in a retort, and microchannel diameter and length. A flexible pouch was used in an in situ immersion biotest coupled with a state-of-the-art retort. Microchannel diameters of 10 to 661μm with 3- and 6-mm lengths were created by placing tungsten wires in vacuum heat-sealed flexible pouches. After removing the wires, these pouches were subsequently heat processed under pressure. They were then biotested in cooling water containing 103 and 106 CFU of motile Enterobacter aerogenes per ml for 30 min and were dried immediately after manual unloading. After incubation at 37°C for 3 days, they were visually examined for contamination. The high-temperature retorting process was shown to decrease microchannel diameters by an average of 20%. Generally, the smaller the microchannel diameter, the greater the percent shrinkage. Statistical analysis of the biotesting data showed that microchannel diameter and length had strong effects on microbial penetration (P < 0.01). Microbial concentration had a borderline significant effect (P < 0.05), but the effect of package location in the retort was not significant. At conservative conditions, such as a 3-mm microchannel length and a cooling water contamination level of 106 CFU/ml, the selected microorganism can penetrate microchannels with diameters as small as 7 μm. However, the minimum microchannel diameter for penetration could be as large as 46μm at practical conditions of 6-mm microchannel length and contamination levels of 103 CFU/ml.

Heat-Pasteurization Process for Inactivation of Nonproteolytic Types of Clostridium botulinum in Picked Dungeness Crabmeat

Development of a heat-pasteurization process is described for picked meat of Dungeness crabs ( Cancer magister ) contained in oxygen-impermeable flexible pouches, For each time-temperature treatment, 30 samples, each inoculated with an equal mixture of three strains of C. botulinum nonproteolytic type B, for a total of 107 spores, provided the basis for calculation of the thermal resistance (a 7D process). Following heat processing, the crabmeat was removed from the pouches and transferred to enrichment medium where it was incubated anaerobically for 150 days. Endpoints at which spores survived were determined by the presence of toxin in the enrichment medium. Process times ranged from 90 min at 88.9°C to 20.3 min at 94.4°C. D values (the time at each temperature required to reduce the inoculum by 1 log) ranged from 12.9 for the 88.9°C process to 2.9 for the 94.4°C process. The relative sterilization value, F0 was .054 and the pasteurization value, , was 240. This pasteurization process safely extends refrigerated shelf life by inactivating spores of Clostridium botulinum nonproteolytic types B, E, and F and also non-spore-forming pathogens such as Listeria monocytogenes . The process does not, however, inactivate the heat-resistant proteolytic strains of C. botulinum or other more heat-resistant spore-formers. The packages and master cartons of the pasteurized product, therefore, should be labeled "Keep refrigerated-Continuous refrigeration below 38°F (3.3°C) required."

A Comparison of Brand Name Commercial Ration Systems Under Military Field Conditions

ABSTRACT The United States Army identified a need for a lightweight, self-heating, shelf stable., nutritionally complete ration packaged in a familiar configuration. This new self-heating ration should use a tray configuration as opposed to flexible pouches used in the current Meal, Ready-to-Eat (MRE). This ration will fill the void between an individual combat ration and a group feeding ration. Operation Desert Storm revealed that operational ration producers required between three and six months to fully meet mobilization ration requirements. The Meal ordered Ready-to-Eat (Contingency Test), MORE(CT) addressed the potential production shortfalls and lag time between start-up and full-scale production of fielded operational rations by using commercial components. A new Self-heating Meal, Operational, Ready to Eat (SMORE) which incorporated the strengths of the MORE(CT) in a tray form with self-heating capability was tested in this study. The operational concept of the SMORE system is to utilize recogniza...