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PubMed2000

Bacterial populations associated with bulk packaged beef supplemented with dietary vitamin E.

Five Simmentaler type calves were fed diets supplemented with 500 mg vitamin E per day and five fed control diets, Rump steaks from each carcass were PVC-overwrapped and bulk packaged in 100% CO2 or 20% CO2:80% O2. Bulk packs were stored up to 42 days at 4 degrees C and PVC-overwrapped samples subsequently displayed up to 7 days at 4 degrees C. After display the Aerobic Plate Count (APC) of steaks was determined and four colonies were randomly selected from the highest dilution APC plates showing growth. A total of 627 colonies were obtained. Gram-reaction, catalase, oxidase, morphology and motility of the isolates were determined. The gram-negative and gram-positive isolates were then identified using a dichotomous identification key. Enterobacteriaceae, Pseudomonas spp. and Acinetobacter spp. predominated on rump steaks from both feeding treatments and in packaging treatments. After 42 days bulk storage Enterobacteriaceae, Pseudomonas spp., lactic acid bacteria and Acinetobacter spp. predominated in 20% CO2:80% O2 and 100% CO2 bulk packaging. Enterobacteriaceae, Pseudomonas spp. and Acinetobacter spp. predominated on rump steaks, from both feeding and packaging treatments, during the aerobic display period of 7 days.

Animal Feed↗
PubMed2000

Isolation and characterization of Carnobacterium, Lactococcus, and Enterococcus spp. from cooked, modified atmosphere packaged, refrigerated, poultry meat.

The microbiota of commercially produced, cooked and modified atmosphere packaged poultry meat was followed during storage at 3.5 degrees C for up to 7 weeks. The dominant microbiota consisted of Lactococcus raffinolactis (117 isolates), Carnobacterium divergens (61 isolates), Carnobacterium piscicola (11 isolates), Lactococcus garvieae (four isolates), Lactococcus lactis (one isolate) and Enterococcus faecalis (three isolates). All isolates were screened for production of bacteriocins. Only C. piscicola isolates produced an inhibitory substance active against other lactic acid bacteria and against several Listeria spp. Species-specific polymerase chain reaction (PCR) primers were used for the differentiation of Carnobacterium, L. raffinolactis, L. lactis, and L. garvieae strains associated with the modified atmosphere packaged poultry products. No false PCR products were observed with other closely related bacterial species.

Animals↗
PubMed2003

Use of double packaging and antioxidant combinations to improve color, lipid oxidation, and volatiles of irradiated raw and cooked turkey breast patties.

The effects of antioxidants and double packaging combinations on color, lipid oxidation, and volatiles production in irradiated raw and cooked turkey breast were determined. Ground meat was treated with antioxidants (none, sesamol + alpha-tocopherol, or gallate + alpha-tocopherol), and patties were prepared. The patties were packaged under vacuum, packaged aerobically, or double packaged (vacuum for 7 d then aerobic for 3 d) and electron beam irradiated at 3 kGy. Color, 2-thiobarbituric acid-reactive substances (TBARS), and volatile profiles of the samples were determined at 0 and 10 d and after cooking. Irradiated vacuum-packaged patties had great amounts of sulfur volatiles (dimethyl sulfide and dimethyl disulfide) and increased red color during refrigerated storage and after cooking compared with the nonirradiated control. Irradiated aerobically packaged meat had accelerated lipid oxidation and aldehyde production at 10 d and after cooking. Gallate + alpha-tocopherol alone with double packaging was effective in reducing the red color of irradiated meat at 10 d and after cooking. Considerable amounts of off-odor volatiles were reduced by double packaging and antioxidant treatment. Sulfur volatiles were evaporated during the aerobic period of double packaging, and lipid oxidation was prevented by the antioxidants and vacuum condition of double packaging. These beneficial effects of double packaging and antioxidants were more critical in irradiated cooked meat. Therefore, the combined use of antioxidants and double packaging would be a useful method to control the oxidative quality changes of irradiated raw and cooked turkey breast.

Animals↗
PubMed2006

Effects of polyvinyl chloride overwrap film, high-oxygen modified atmosphere packaging, or ultra-low-oxygen modified atmosphere packaging on bone marrow discoloration in beef humerus, rib, thoracic vertebra, and scapula.

Meat retailers have reported bone marrow discoloration to be a problem, especially in modified atmosphere packages (MAP). Therefore, it is important to determine the prevalence and cause(s) of bone marrow discoloration in different beef bones and packaging systems. Thirty-six beef humeri, ribs, scapulas, and thoracic vertebrae from USDA Select and Choice carcasses were obtained from a commercial abattoir, cut into 2.54-cm-thick sections at 4 d postmortem, and packaged into 1 of 3 systems: 1) polyvinyl chloride film (PVC) overwrap; 2) high-oxygen (80% O2, 20% CO2) MAP; and 3) ultra-low-oxygen (70% N2, 30% CO2) MAP. Instrumental reflectance and visual color scores were taken on d 0, 2, and 4, and on d 0 to 4 of display, respectively. Bone marrow was extracted from humeri, ribs, and thoracic vertebrae for analysis but not from scapulas. Ribs, scapulas, and thoracic vertebrae packaged in PVC and high-oxygen MAP developed undesirable gray or black discoloration. In ultra-low-oxygen MAP, mean visual color scores were acceptable throughout the entire display period. Discoloration (darkening) was more extensive for ribs, scapulas, and thoracic vertebrae than for humeri, especially for bones packaged in PVC and high-oxygen MAP. Humeri had lower (P < 0.05) a* values (larger positive a* values indicate a redder color) than the other bones. The a* values for ribs, scapulas, and thoracic vertebrae decreased (P < 0.05) over time. Chroma showed that bone marrow discolored during display, but graying was dramatically less for all bones packaged in ultra-low-oxygen MAP and for humeri in PVC and high-oxygen MAP. Humeri marrow had lower (P < 0.05) 2-thiobarbituric acid reactive substances (TBARS) than did ribs and thoracic vertebrae marrow. Ultra-low-oxygen MAP resulted in the least amount of change in TBARS from d 0 to 4, whereas thoracic vertebrae marrow had greater (P < 0.05) TBARS values at d 4 of display than at d 0 in PVC and high-oxygen MAP. Humeri marrow had dramatically less total Fe and hemoglobin than did that of ribs and thoracic vertebrae for all packaging systems. Myoglobin was undetectable in humeri marrow. The much larger amounts of Fe and hemoglobin in ribs and thoracic vertebrae likely contribute to marrow discoloration. Bone marrow discoloration was distinct in ribs, scapulas, and thoracic vertebrae packaged in PVC or high-oxygen MAP. Bones packaged in ultra-low-oxygen MAP had minimal discoloration.

Animals↗
PubMed2003

Microbiological and physicochemical properties of fresh retail cuts of beef packaged under an advanced vacuum skin system and stored at 4 degrees C.

The effect of an advanced vacuum skin packaging system on the microbiological and physicochemical properties of fresh retail cuts of beef (including meat portions from six different anatomical regions) stored at 4 degrees C was compared with the effect of traditional vacuum packaging. The vacuum skin packaging system whose effect on meat quality was evaluated in this work displayed two remarkable features: (i) the instantaneous heating of the lower surface of the upper film of the package before the film descended over the meat surface and (ii) the tight disposition of the plastic film on the meat surface, which avoided wrinkles and purges. Throughout storage at 4 degrees C, rates of bacterial growth were statistically significantly slower in beef portions processed with the vacuum skin packaging system than in those processed with traditional vacuum packaging, with average differences of 2.07, 1.60, and 1.25 log CFU/g in counts of aerobic mesophiles, anaerobes, and lactic acid bacteria, respectively. pH values were statistically significantly lower for beef portions packaged with the vacuum skin system than for those that were vacuum packaged in the traditional manner, probably because of the relative predominance of lactic acid bacteria observed in such samples, which coincided with both higher meat firmness values and a slower meat tenderization process. The vacuum skin system prevented the appearance of undesirable coloration on the meat surface and also significantly improved the commercial color of the meat as determined on the basis of luminosity (L*) and the redness (a*). Overall, the quality (as determined by microbiological and physicochemical analyses and by visual examination) of fresh retail cuts of beef packaged with the vacuum skin system and stored at 4 degrees C was higher than that of meat samples processed with the traditional vacuum-packaging system.

Animals↗
PubMed1996

Influence of unsliced delicatessen meat freshness upon bacterial growth in subsequently prepared vacuum packed slices.

Unsliced beef pastrami, reformulated ham and bologna held at 6 degrees C were sliced 21, 17, 12 or 7 days before or at the assigned manufacturer's best before date and vacuum packaged. Packages of sliced meats were held at 6 degrees C for another 7, 12, 17 or 21 days, opened and analyses made for total bacteria, lactic acid bacteria, Enterobacteriaceae and Brochothrix thermosphacta. The maximum storage interval was 42 days; half this period unsliced, the remainder as repacked slices. Numbers of bacteria on pastrami were significantly greater than on ham and bologna (pastrami > ham > bologna) with the lactic acid bacteria dominating in all products. As unsliced meats approached their best before date, insignificant increases were generally noted for numbers of lactic bacteria, Enterobacteriaceae and B. thermosphacta. During subsequent storage of slices under vacuum, numbers of total and lactic bacteria increased exponentially at the same rate while B. thermosphacta growth was significantly slower. Numbers of Enterobacteriaceae remained low and were essentially unchanged during sliced meat storage. Within the context of study storage parameters, shelf-life appeared to be determined by length of time after slicing and repackaging rather than by best before date of the unsliced meat. Packages of sliced meat prepared from wholesale unsliced meats with 21 days left until their best before date or from unsliced meats with 12 days left until the best before date showed similar bacterial levels 21 days later. It was probable that the localization of bacterial growth at the meat surface-packaging film interface of the unsliced meats yielded slices with initially lowered bacterial content when repackaged and sampled from the uppermost slice. When Enterobacteriaceae and B. thermosphacta were absent from unsliced meats, extension of sliced meat package shelf-life beyond the best before date of the parent meat was possible. However, these bacterial groups were not always undetected.

Enterobacteriaceae↗
PubMed2000

Desorption behavior of sorbed flavor compounds from packaging films with ethanol solution.

Desorption behavior of sorbed flavor compounds such as ethyl esters, n-aldehydes, and n-alcohols from LDPE and PET films was investigated in 0 to 100% (v/v) ethanol solutions at 20 degrees C, 50 degrees C, and 60 degrees C. In both films, the desorption apparently increased with increasing ethanol concentration and treatment temperature, depending on the compatibility of the flavor compound with the solvent. Namely, the partition coefficient of ethyl esters, n-aldehydes, and n-alcohols in the LDPE film turned out to be approximately zero at >/=60%, >/=80%, and >/=40% (v/v) ethanol, respectively (for PET film, >/=80%, >/=80%, and >/=40% (v/v) ethanol concentrations were required for complete desorption, respectively). As for physical properties (heat of fusion, melting point, and tensile strength and elongation at break) of LDPE and PET films, there were no significant differences between intact film and the treated film with 60% (v/v) ethanol for 30 min at 60 degrees C. These results suggest that it is possible to apply a desorption solvent such as ethanol solution for desorption of sorbed flavor compounds from packaging films with no physical change in the film properties by this desorption treatment.

Ethanol↗
PubMed1998

Parts-per-trillion determination of styrene in yoghurt by purge-and-trap gas chromatography with mass spectrometry detection.

Headspace sampling methods prior to capillary gas chromatography have been widely used for the determination of volatile compounds present in very different kinds of samples. This paper describes an automated and rapid system to determine volatiles from yoghurt. Thirty-five volatile organic compounds (VOCs) were identified in polystyrene cups used for yoghurt packaging and 42 VOCs from yoghurt samples. Quantitation of styrene in several samples from the Spanish retail market was carried out.

Chromatography, Gas↗
PubMed2003

Bacteriology and storage life of moisture-enhanced pork.

This study was undertaken to determine the impact of the moisture enhancement process on the bacterial contamination and storage life of vacuum-packaged pork loins. Bone-in and boneless pork loins injected with brine (sodium chloride, sodium phosphate, lemon juice) were obtained from a commercial processing facility and stored for 5 weeks in vacuum packaging at 2 and 5 degrees C. At weekly intervals, samples were excised to determine numbers of spoilage bacteria and pathogens. The loins were subjectively evaluated by a sensory panel to quantify appearance and odor acceptability. Moisture-enhanced loins were initially contaminated with a population of psychrotrophic bacteria that was approximately 2 log units higher than that for noninjected boneless loins. This difference was largely due to contamination by larger numbers of pseudomonads in the brine-injected loins. There were no significant differences in the initial numbers of lactic acid bacteria, Enterobacteriaceae, or Brochothrix thermosphacta. Similar trends in spoilage bacterial populations were observed for moisture-enhanced loins with bones, but Enterobacteriaceae counts were also found to be approximately 1 log unit higher for the injected product. Brine-injected loins generally had larger bacterial numbers at each storage time, but there were no consistent injection treatment effects on bacterial growth. Brine injection did not affect color or odor deterioration, and the storage life for vacuum-packaged loins was the same as that for noninjected controls. The incidence of Listeria monocytogenes was 21% for control loins and 27% for moisture-enhanced loins. Although the brine injection process resulted in an increase in bacterial contamination, there was no evidence that this contamination would affect the storage life of vacuum-packaged loins, and further research is necessary to determine the significance of the increased incidence of L. monocytogenes.

Animals↗
PubMed2003

Development and validation of analytical methods for monomeric and oligomeric migrants from nylon 12 packaging materials.

Analytical methods for the determination of laurolactam--the monomer of nylon 12--as well as the cyclic dimer and trimer were established. High performance liquid chromatography using ultraviolet (HPLC-UV) and mass spectrometric detection (HPLC-MS) were both found suitable to identify and quantify monomer, cyclic dimer and trimer well below the specific migration limit (SML) of laurolactam, being 5 mg/kg of food (simulant). Gas chromatography with flame ionisation detection (GC-FID) showed to be an appropriate method for the detection of only laurolactam in aqueous and fatty food simulants. Food simulants could be analysed directly by all three methods, or after a change of solvents. For olive oil, a method for sample clean-up by size-exclusion chromatography (SEC) was established.

Chromatography, Gas↗
PubMed2005

Production, properties, and applications of hydrocolloid cellular solids.

Many common synthetic and edible materials are, in fact, cellular solids. When classifying the structure of cellular solids, a few variables, such as open vs. closed cells, flexible vs. brittle cell walls, cell-size distribution, cell-wall thickness, cell shape, the uniformity of the structure of the cellular solid and the different scales of length are taken into account. Compressive stress-strain relationships of most cellular solids can be easily identified according to their characteristic sigmoid shape, reflecting three deformation mechanisms: (i) elastic distortion under small strains, (ii) collapse and/or fracture of the cell walls, and (iii) densification. Various techniques are used to produce hydrocolloid (gum) cellular solids. The products of these include (i) sponges, obtained when the drying gel contains the occasionally produced gas bubbles; (ii) sponges produced by the immobilization of microorganisms; (iii) solid foams produced by drying foamed solutions or gels containing oils, and (iv) hydrocolloid sponges produced by enzymatic reactions. The porosity of the manufactured cellular solid is subject to change and depends on its composition and the processing technique. The porosity is controlled by a range of methods and the resulting surface structures can be investigated by microscopy and analyzed using fractal methods. Models used to describe stress-strain behaviors of hydrocolloid cellular solids as well as multilayered products and composites are discussed in detail in this manuscript. Hydrocolloid cellular solids have numerous purposes, simple and complex, ranging from dried texturized fruits to carriers of vitamins and other essential micronutrients. They can also be used to control the acoustic response of specific dry food products, and have a great potential for future use in countless different fields, from novel foods and packaging to medicine and medical care, daily commodities, farming and agriculture, and the environmental, chemical, and even electronic industries.

Acoustics↗
PubMed1999

Irradiation and modified atmosphere packaging for the control of Listeria monocytogenes on turkey meat.

When radiation-sterilized ground turkey meat was inoculated with Listeria monocytogenes, packaged under mixtures of nitrogen and carbon dioxide, and irradiated with gamma-radiation doses of 0 to 3.0 kGy, there was a statistically significant (P < 0.05), but probably not a biologically significant, lower (0.39 log) predicted bacterial survival in the presence of 100% carbon dioxide than in the presence of 100% nitrogen. Possibly because all atmospheres contained oxygen and because a response surface design was used, gamma-radiation resistance was not significantly (P < 0.05) different in air than in modified atmosphere packaging (MAP) mixtures containing 5% O2 or containing 20, 40, 60, and 80% CO2 and balance N2. The antilisterial effects of MAP mixtures containing 17.2, 40.5, and 64% CO2 and balance N2 were compared to those associated with air and vacuum packaging on turkey inoculated with approximately 5 x 10(3) CFU/g. Samples were irradiated to doses of 0, 0.5, 1.0, 1.5, 2.0, and 2.5 kGy and were stored at 7 degrees C for up to 28 days. Irradiation treatments were significantly more lethal in the presence of air packaging than in either vacuum packaging or MAP, and in those samples that received >1.0 kGy, there was a concentration-dependent CO2 inhibition of L. monocytogenes multiplication and/or recovery.

Animals↗
PubMed1999

Microbiological quality and production of botulinal toxin in film-packaged broccoli, carrots, and green beans.

The production of toxin by a 10-strain mixture of proteolytic Clostridium botulinum in fresh produce packaged in polyethylene films with different oxygen permeability was determined. Broccoli florets, shredded carrots, and green beans inoculated with approximately 10(2) C. botulinum spores per g were placed in bags (1.4 kg per bag) composed of four films with different oxygen transmission rates (OTRs). Broccoli was packaged in bags with OTRs of 3 (7,000 cm3/m2/24 h) and 4 (16,000 cm3/m2/24 h), and green beans were packaged in bags with OTRs of 2 (6,000 cm3/m2/24 h) and 4. Broccoli and green beans in bags were compressed and heat-sealed. Shredded carrots were packaged in bags with OTRs of 1 (3,000 cm3/m2/24 h) and 3 and vacuum-sealed. Produce was stored at 4, 13, and 21 degrees C for up to 27 (broccoli) or 28 (carrots and green bean) days and analyzed periodically. At each sampling time, gas composition within the bags, pH of the produce microbial population (total aerobic and anaerobic microorganisms, lactic acid bacteria, psychrotrophic bacteria, yeasts, and molds), and the presence or absence of botulinal toxin were determined. Packaging material affected the quality of vegetables, especially broccoli stored at 4 and 13 degrees C. For example, broccoli was scored as "good" after 22 days at 4 degrees C when it was packaged in film with higher gas permeability (OTR of 4), whereas broccoli appeared to be in "poor" condition when packaged in film with lower gas permeability (OTR of 3). With the exception of lactic acid bacteria, packaging material did not noticeably influence the growth of microorganisms. Lactic acid bacteria grew better in broccoli packaged in bags with an OTR of 3 than in those with an OTR of 4 at all temperatures. Botulinal toxin was detected in broccoli packaged in bags with an OTR of 3 and stored at 13 degrees C for 21 days and in those with an OTR of 4 and 3 and stored at 21 degrees C for 10 days. All toxic samples were visibly spoiled. Toxin was not detected in produce packaged under any other test conditions.

Botulinum Toxins↗
PubMed1996

Survival and growth of Aeromonas hydrophila on modified atmosphere packaged normal and high pH lamb.

The growth of A. hydrophila on normal pH (5.5-5.8) and high pH ( > 6.0) lamb stored under modified atmospheres was examined. Lamb pieces and mince, inoculated with A. hydrophila were packaged in air, vacuum pack, 80% O2/20% CO2, 50% CO2/50% N2, or 100% CO2 and stored at 5 or 0 degrees C for up to 42 days. Samples were examined for the survival and/or growth of A. hydrophila by enrichment in alkaline peptone water and/or direct plating on starch ampicillin agar. The pH of each sample was estimated. On lamb pieces and mince of normal pH, A. hydrophila numbers decreased during storage at 5 and 0 degrees C under all the packaging conditions. The organism was not detected after 21 days storage. In contrast, A. hydrophila numbers were maintained or increased on high pH lamb under most storage regimes. Storage at 5 degrees C allowed significant increases in A. hydrophila numbers on high pH lamb under all the atmospheres, except 100% CO2. In lamb held at 5 degrees C under 100% CO2 for up to 42 days, A. hydrophila was recovered from most samples, although cell numbers decreased during storage. After storage at 0 degrees C, A. hydrophila was recovered from high pH packs stored under all atmospheres. Significant increases in cell numbers were only observed in minced lamb of high pH stored under air or vacuum. The pH values of lamb pieces and mince held at 5 or 0 degrees C under any of the packaging atmospheres did not change in a uniform manner during storage.

Aeromonas hydrophila↗
PubMed2005

Evolution of aroma compounds from orange juice stored in polyethylene terephthalate (PET).

The evolution of aroma compounds from orange juice made from concentrate and stored in glass, standard monolayer polyethylene terephthalate (PET 1), multilayer PET (PET 2) and plasma-treated PET (internal carbon coating) (PET 3) was investigated. Bottles were stored at room temperature (20 degrees C) under artificial light. Volatile compounds in orange juice samples and corresponding packaging materials were analysed at zero time and after 2, 3 and 5 months of storage. After 5 months of storage, from 0.2 to 0.3% of the initial amounts of limonene and beta-myrcene in the orange juice had been absorbed by the plastic packaging materials. Statistical analyses showed that the evolution of aroma compounds was strongly correlated to the duration of storage, but not to the type of packaging material. Indeed, whatever the stored orange juice samples, the same evolutions were observed, with a decrease in aldehydes and ketones, esters, aliphatic alcohols, sesquiterpene and monoterpene alcohols, and an increase in two aliphatic and monoterpene alcohols (i.e. furfural and 4-vinylguaicol). The results suggest that the losses of aroma compounds from the juice could be attributed to the high acidity of the matrix, implying acid-catalysed reactions. Finally, PET packaging materials and their corresponding oxygen permeabilities showed no correlation with the loss of aroma compounds.

Absorption↗
PubMed2000

Review of centralized packaging systems for distribution of retail-ready meat.

There is growing interest in centralized preparation of retail-ready meat cuts for distribution to widely dispersed retail stores due to the convenience of having high-quality ready-to-go products that are consistently provided to consumers at lower cost. Various centralized packaging techniques are described. Of all packaging techniques, master packaging is the most economical and shows promise for commercial application. Nevertheless, the master-packaging technique must be integrated with strict temperature control in a narrow range just above freezing (- 1.5 +/- 0.5 degrees C), good processing hygiene, and maintenance of a completely anoxic atmosphere in the package headspace throughout the distribution period to maximize storage life. Packaging using the CAPTECH process reduces the residual O2 present in the headspace to 300 ppm. Oxygen scavengers must be incorporated in the package to absorb the residual O2 and preserve the metmyoglobin reducing activity of meat tissues. Integration of all these technologies can provide a storage life of retail-ready meat up to 10 weeks in the master package followed by 3 days of retail display life. This extension of storage life is sufficient for transporting meat to distant markets.

Animals↗
PubMed2003

Modelling permeation through porous polymeric films for modified atmosphere packaging.

The use of perforated packaging films is increasing with the application of modified atmosphere packaging for fresh produce. These films provide high to very high mass exchange rates. However, irrespective of the chemistry of the material, mass transport through such films cannot be described using conventional permeability equations (Henry's plus Fick's laws). Other expressions such as Knudsen's law, gas diffusivities or Poiseuille's hydrodynamic flow can be applicable. The application of these laws is discussed and their corresponding range of validity is provided. These laws were also applied to model experimental permeation rates of oxygen and water and were further used to describe the headspace evolution of two fruit products in modified atmosphere packaging. In the light of these results, the contribution of different factors to the headspace evolution is discussed.

Chromatography, Gas↗
PubMed2001

Effects of vegetable type, package atmosphere and storage temperature on growth and survival of Escherichia coli O157:H7 and Listeria monocytogenes.

The survival and growth of Escherichia coli O157:H7 (ATCC 43888 and NCTC 12900) and Listeria monocytogenes (ATCC 19114 and NCTC 11994) during storage (4 and 8 degrees C) on ready-to-use (RTU) packaged vegetables (lettuce, swedes (rutabaga), dry coleslaw mix, soybean sprouts) were studied. The vegetables were sealed within oriented polypropylene packaging film, and modified atmospheres developed in packs during storage due to produce respiration. Survival and growth patterns were dependent on vegetable type, package atmosphere, storage temperature and bacterial strain. Populations of L. monocytogenes and E. coli O157:H7 increased (P<0.05, by 1.5 to 2.5 log cycles, depending on strain) during a 12-day storage period on shredded lettuce (8 degrees C). L. monocytogenes populations also increased (by approximately 1 log cycle) on packaged swedes, did not change significantly (P>0.05) in packages of soybean sprouts and decreased by approximately 1.5 log cycles (P<0.05) on coleslaw mix (8 degrees C). E. coli O157:H7 populations on packaged coleslaw and soybean sprouts increased (by 1.5 to 2.5 log cycles) up to day 5, but declined during subsequent storage (8 degrees C). On packaged swedes (8 degrees C), populations of E. coli O157:H7 strain ATCC 43888 increased (by approximately 1 log cycle) during storage, whereas populations of strain 12900 increased between days 2 and 5, and declined during subsequent storage. Reducing the storage temperature from 8 to 4 degrees C reduced the growth of L. monocytogenes and E. coli O157:H7 on packaged RTU vegetables. However, viable populations remained at the end of the storage period at 4 degrees C.

Carbon Dioxide↗