EFFECT OF CUTTING STYLE, LOW-OXYGEN ATMOSPHERE AND COLD TEMPERATURE ON THE RESPIRATION RATE OF MINIMALLY PROCESSED VEGETABLES

The red blood cells of the human fetus differ in many major respects from the red cells of the normal adult. These differences appear admirably suited for the acquisition, transport, and release of oxygen in the low oxygen atmosphere of intrauterine existence. These same differences appear to confer a handicap to the cell in the extrauterine environment, particularly under conditions of hypoxic stress. The rapid replacement of these cells by artificial means, such as early exchange transfusion, may offer an advantage to the newborn infant in certain clinical situations.

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Comparison of Four Commercial DNA Extraction Kits for PCR Detection of Listeria monocytogenes, Salmonella, Escherichia coli O157:H7, and Staphylococcus aureus in Fresh, Minimally Processed Vegetables

Journal of Food Protection ◽

10.4315/0362-028x-71.10.2110 ◽

2008 ◽

Vol 71 (10) ◽

pp. 2110-2114 ◽

Cited By ~ 25

Author(s):

P. ELIZAQUÍVEL ◽

R. AZNAR

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Listeria Monocytogenes ◽

Dna Extraction ◽

Pcr Detection ◽

Escherichia Coli O157 ◽

Minimally Processed ◽

Green Pepper ◽

Minimally Processed Vegetables ◽

And Staphylococcus Aureus

Four commercial DNA extraction methods, PrepMan Ultra (Applied Biosystems), InstaGene Matrix (BioRad), DNeasy Tissue kit (Qiagen), and UltraClean (MoBio), were tested for PCR detection of Listeria monocytogenes, Escherichia coli O157: H7, Salmonella, and Staphylococcus aureus in fresh, minimally processed vegetables. For comparative purposes, sensitivity assays with specific PCRs were carried out after DNA extraction with the four methods in green pepper, broccoli, and onion artificially inoculated with the four pathogens separately. As confirmed by statistical analysis, the DNeasy Tissue kit rendered the highest sensitivity values in the three matrices assayed for Salmonella, L. monocytogenes, and E. coli O157:H7 and in onion for S. aureus. Despite being the most expensive of the methods compared, the DNeasy Tissue Kit can be successfully applied for any of the four most commonly studied pathogens, thus saving time and overall reducing the cost of the analysis.

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Susceptibility of minimally processed green pepper and cucumber to chilling injury as observed by apparent respiration rate

International Journal of Food Science & Technology ◽

10.1046/j.1365-2621.1997.00129.x ◽

1997 ◽

Vol 32 (5) ◽

pp. 421-426 ◽

Cited By ~ 20

Author(s):

Jun Soo Kang ◽

Dong Sun Lee

Keyword(s):

Respiration Rate ◽

Chilling Injury ◽

Minimally Processed ◽

Green Pepper

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Effects of Low-oxygen Atmosphere on Ethanolic Fermentation in Fresh-cut Carrots

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.122.1.107 ◽

1997 ◽

Vol 122 (1) ◽

pp. 107-111 ◽

Cited By ~ 41

Author(s):

Hisashi Kato-Noguchi ◽

Alley E. Watada

Keyword(s):

Alcohol Dehydrogenase ◽

Daucus Carota ◽

Continuous Flow ◽

Pyruvate Decarboxylase ◽

Oxygen Atmosphere ◽

Low Oxygen ◽

Ethanolic Fermentation ◽

Fresh Cut ◽

Fermentation Metabolism

Carrot (Daucus carota L.) root shreds were stored under a continuous flow of 0.5% and 2% O2 (balance N2) or in air for 7 days at 5 and 15 °C to study the regulation of ethanolic fermentation metabolism. Low-O2 atmospheres of 0.5% and 2% caused increases in ethanol and acetaldehyde concentrations and the activities of alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC) compared to air. By day 3, ethanol increased 38-, 25-, 13-, and 9.5-fold; acetaldehyde increased 20-, 13-, 7.7-, and 5.6-fold; ADH increased 7.6-, 6.3-, 3.8-, and 2.7-fold; and PDC increased 4.2-, 3.9-, 2.3-, and 2.2-fold in samples at 0.5% O2 at 15 or 5 °C and at 2% O2 at 15 or 5 °C, respectively, compared with corresponding samples in air. These results indicate that ethanolic fermentation was accelerated more in the 0.5% than in the 2% O2 atmosphere and more at 15 °C than at 5 °C. The acceleration of ethanolic fermentation may allow production of some ATP, which may permit the carrot tissues to survive.

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Microbiological and Sensory Quality of Fresh Ready-to-Eat Artichoke Hearts Packaged under Modified Atmosphere

Journal of Food Protection ◽

10.4315/0362-028x.jfp-16-289 ◽

2017 ◽

Vol 80 (5) ◽

pp. 740-749 ◽

Cited By ~ 2

Author(s):

Nuria García-Martínez ◽

Pedro Andreo-Martínez ◽

Luis Almela ◽

Lucía Guardiola ◽

José A. Gabaldón

Keyword(s):

Shelf Life ◽

Storage Temperature ◽

Modified Atmosphere Packaging ◽

Threshold Value ◽

Plate Count ◽

Vacuum Impregnation ◽

Modified Atmosphere ◽

Minimally Processed ◽

Sensory Qualities ◽

Minimally Processed Vegetables

ABSTRACT In recent years the sales of minimally processed vegetables have grown exponentially as a result of changes in consumer habits. The availability of artichoke buds as a ready-to-eat product would be, therefore, highly advantageous. However, minimally processed artichoke hearts are difficult to preserve because of their rapid browning and the proliferation of naturally occurring microorganisms. We developed artichoke hearts prepared as ready-to-eat products that maintain the characteristics of the fresh product. The microbiological stability, sensory qualities, and shelf life of the processed artichoke hearts were determined. During the shelf life, Salmonella, Listeria monocytogenes, and Escherichia coli counts were below the limits legally established by European regulations for minimally processed vegetables. The pH played an important role in microbial growth. Artichoke hearts had lower microbial counts in experiments conducted at pH 4.1 than in experiments conducted at pH 4.4, although the recommended threshold value for total plate count (7 log CFU/g) was not exceeded in either case. Sensory parameters were affected by the microorganisms, and artichoke products at lower pH had better sensory qualities. Vacuum impregnation techniques, modified atmosphere packaging, and low storage temperature were very effective for increasing the shelf life of minimally processed artichokes. The average shelf life was approximately 12 to 15 days.

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Radiation Processing To Ensure Safety of Minimally Processed Carrot (Daucus carota) and Cucumber (Cucumis sativus): Optimization of Dose for the Elimination of Salmonella Typhimurium and Listeria monocytogenes

Journal of Food Protection ◽

10.4315/0362-028x-69.2.444 ◽

2006 ◽

Vol 69 (2) ◽

pp. 444-448 ◽

Cited By ~ 23

Author(s):

V. S. DHOKANE ◽

S. HAJARE ◽

R. SHASHIDHAR ◽

A. SHARMA ◽

J. R. BANDEKAR

Keyword(s):

Listeria Monocytogenes ◽

Salmonella Typhimurium ◽

Escherichia Coli O157 ◽

Radiation Processing ◽

Minimally Processed ◽

Shigella Species ◽

Storage Studies ◽

D Values ◽

Minimally Processed Vegetables ◽

Control Samples

Minimally processed vegetables are in demand, because they offer convenience to consumers. However, these products are often unsafe because of possible contamination with pathogens, such as Salmonella, Escherichia coli O157:H7, and Shigella species. Therefore, this study was carried out to optimize the radiation dose necessary to ensure the safety of precut carrot and cucumber. Decimal reduction doses (D-values) of Salmonella Typhimurium MTCC 98 were ca. 0.164 kGy in carrot samples and 0.178 kGy in cucumber samples. D-values of Listeria monocytogenes were determined to be 0.312 and 0.345 kGy in carrot and cucumber samples, respectively. Studies of inoculated, packaged, minimally processed carrot and cucumber samples showed that treatment with a 1-kGy dose of gamma radiation eliminated up to 4 log CFU/g of Salmonella Typhimurium and 3 log CFU/g of L. monocytogenes. However, treatment with a 2-kGy dose was necessary to eliminate these pathogens by 5 log CFU/g. Storage studies showed that both Salmonella Typhimurium and L. monocytogenes were able to grow at 10°C in inoculated control samples. Neither of these pathogens could be recovered from radiation-processed samples after storage for up to 8 days.

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