Effect of Low-Dose Gamma Irradiation on Staphylococcus aureus and Product Packaging in Ready-to-Eat Ham and Cheese Sandwiches

2002 ◽  
Vol 65 (11) ◽  
pp. 1800-1805 ◽  
Author(s):  
JENNIFER L. LAMB ◽  
JENNIFER M. GOGLEY ◽  
M. JASMINE THOMPSON ◽  
DANIEL R. SOLIS ◽  
SUMIT SEN
Keyword(s):  
Staphylococcus Aureus ◽  
Gamma Irradiation ◽  
Ftir Spectroscopy ◽  
Low Dose ◽  
Plate Count ◽  
Refrigerated Storage ◽  
Product Packaging ◽  
Standard Plate Count ◽  
Log Reduction ◽  
Standard Plate

Staphylococcus aureus is a common pathogen that causes foodborne illness. Traditional methods for controlling S. aureus do not address postprocess contamination. Low-dose gamma irradiation is effective in reducing pathogens in a variety of foods and may be effective in reducing S. aureus in ready-to-eat foods. The effects of gamma irradiation on product packaging should also be considered. The objective of this study was to determine the effects of gamma irradiation on product packaging and on S. aureus in ready-to-eat ham and cheese sandwiches. The effects of refrigerated storage on irradiated and nonirradiated sandwiches were also investigated. Ham and cheese sandwiches were inoculated with 106 or 107 CFU of S. aureus per g, frozen, irradiated, and analyzed by a standard plate count method. D10-values, the amount of irradiation needed to elicit a 1-log10 reduction of bacteria, were calculated. In addition, irradiated sandwiches were analyzed after 1, 13, 27, and 39 days of storage at 4°C. The integrity of postirradiated packaging material was analyzed using Fourier transform infrared (FTIR) spectroscopy. Two experiments yielded D10-values of 0.62 and 0.63. During refrigerated storage, sandwiches irradiated with 5.9 kGy showed no S. aureus growth at any time; sandwiches irradiated with 3.85 kGy showed a 6.18-log reduction in S. aureus after 13 days; and nonirradiated sandwiches showed a 0.53-log increase in S. aureus after 39 days. FTIR spectroscopy showed that the label side and the bulge side were composed of polyethylene terephthalate and nylon 6, respectively. No significant change in the packaging due to irradiation was detected. In this study, low-dose gamma irradiation was shown to be an effective method for reducing S. aureus in ready-to-eat ham and cheese sandwiches and proved to be more efficacious than refrigeration alone. Additionally, package integrity was not adversely affected by gamma irradiation.

Precision Parameters for the FDA Shellfish Laboratory Quality Assurance Program for 1973–1989

1995 ◽  
Vol 58 (6) ◽  
pp. 648-650
Author(s):  
JAMES T. PEELER ◽  
THOMAS E. GRAHAM ◽  
LARRY J. MATURIN
Keyword(s):  
Staphylococcus Aureus ◽  
Quality Assurance ◽  
Fecal Coliform ◽  
Quality Assurance Program ◽  
Plate Count ◽  
Most Probable Number ◽  
Probable Number ◽  
Standard Plate Count ◽  
Standard Plate ◽  
The U.S

Precision parameters from four microbiological analytical methods (coliform most probable number [MPN], fecal coliform MPN, Staphylococcus aureus plate count and standard plate count) were computed for the Shellfish Quality Assurance Program of the U.S. Food and Drug Administration (FDA). The pooled reproducibility variance (SR2) for the four methods from 1973 to 1989 were 0.0778, 0.1181, 0.0137, and 0.0087, respectively.

Implementation of hazard analysis critical control point in jameed production

2012 ◽  
Vol 18 (3) ◽  
pp. 229-239 ◽  
Author(s):  
AK Al-Saed ◽  
RM Al-Groum ◽  
MM Al-Dabbas
Keyword(s):  
Staphylococcus Aureus ◽  
Hazard Analysis ◽  
Control Point ◽  
Plate Count ◽  
Point System ◽  
Control Points ◽  
Critical Control Point ◽  
Standard Plate Count ◽  
Critical Control Points ◽  
Standard Plate

The average of standard plate count and coliforms, Staphylococcus aureus and Salmonella counts for three home-made jameed samples, a traditional fermented dairy product, before applying hazard analysis critical control point system were 2.1 × 103, 8.9 × 101, 4 × 101 and less than 10 cfu/g, respectively. The developed hazard analysis critical control point plan resulted in identifying ten critical control points in the flow chart of jameed production. The critical control points included fresh milk receiving, pasteurization, addition of starter, water and salt, straining, personnel hygiene, drying and packaging. After applying hazard analysis critical control point system, there was significant improvement in the microbiological quality of the home-made jameed. The standard plate count was reduced to 3.1 × 102 cfu/g whereas coliform and Staphylococcus aureus counts were less than 10 cfu/g and Salmonella was not detected. Sensory evaluation results of color and flavor of sauce prepared from jameed showed a significant increase in the average scores given after hazard analysis critical control point application.

Pyruvate as an Indicator of Quality in Grading Nonfat Dry Milk1

1982 ◽  
Vol 45 (6) ◽  
pp. 561-565 ◽  
Author(s):  
R. T. MARSHALL ◽  
Y. H. LEE ◽  
B. L. O'BRIEN ◽  
W. A. MOATS
Keyword(s):  
Geometric Mean ◽  
Regression Line ◽  
Skim Milk ◽  
Plate Count ◽  
Department Of Agriculture ◽  
Standard Plate Count ◽  
Geometric Average ◽  
Dry Milk ◽  
Standard Plate ◽  
Microscopic Count

Samples of skim milk and nonfat dry milk (NDM) made from it were collected, paired and tested for pyruvate concentration, [P], and Direct Microscopic count (DMC). The skim milk was tested for Standard Plate Count (SPC) and Psychrotrophic Plate Count (PPC). The geometric average DMC of skim milk was more than three times higher than that of the paired NDM samples. However, [P] of NDM was not significantly different from that of the skim milk. Although [P] of skim milk was poorly correlated with SPC and PPC, r = .31 and .26, respectively, it was relatively well correlated with DMC, r = .64. Data were widely dispersed around the regression line when [P] was ≤ 4.0 mg/L. However, [P] increased rapidly when DMCs were > 106/ml. A limit of 10 mg/L of [P] in NDM reconstituted 1:9 was chosen to represent the current U.S. Department of Agriculture Standard for DMC in NDM. This limit failed to classify about 10% of the samples correctly, assuming that each geometric mean DMC was correct. However, the probability that samples meeting the DMC standard would be rejected by the pyruvate test was quite low and the probability was moderate that samples which would be acceptable by the pyruvate test would be rejected by the DMC. For the latter, 28% of the samples having DMCs of ≥ 107/ml contained < 10 mg/L of pyruvate. No sample having ≥ 10 mg/L of pyruvate had a DMC of ≤ 107/ml. Pyruvate concentration in NDM did not change during storage at 5 or 32°C for 90 days.

Bioluminescence: A Rapid Indicator of Escherichia Coli O157:H7 in Selected Yogurt and Cheese Varieties

1997 ◽  
Vol 60 (8) ◽  
pp. 891-897 ◽  
Author(s):  
L. M. HUDSON ◽  
J. CHEN ◽  
A. R. HILL ◽  
M. W. GRIFFITHS
Keyword(s):  
Escherichia Coli ◽  
Enterohemorrhagic Escherichia Coli ◽  
Cottage Cheese ◽  
Plate Count ◽  
Escherichia Coli O157 ◽  
Potential Hazard ◽  
Growth And Survival ◽  
E Coli ◽  
Standard Plate Count ◽  
Standard Plate

Outbreaks of enterohemorrhagic Escherichia coli O157:H7 have been commonly associated with products derived from ground beef, but recently the organism has been implicated as the causative agent in outbreaks involving yogurt and cheese. This finding has raised concern about the potential for its growth and survival in fermented dairy products. A bioluminescent strain of E. coli O157:H7 was used to determine postprocessing survival in yogurt with live cultures at pH 4.17, 4.39, and 4.47 stored at 4 and 10°C. In addition, survival of E. coli O157:H7 was monitored during the manufacture of Cottage, Colby, Romano, and Feta cheeses. Results indicated survival for 8 and 5 days at 4 and 10°C respectively in yogurt at pH 4.17, 17 and 15 days at 4 and 10°C respectively in yogurt at pH 4.39, and 17days at both 4 and 10°C in yogurt at pH 4.47. E. coli O157:H7 did not survive cooking procedures at 56°C in Cottage cheese. However, the pathogen survived for 27, 30, and 27 days in Colby, Romano, and Feta cheeses respectively. A high correlation of r2 > 0.89 was obtained between counts of bioluminescenct colonies and standard plate count for all yogurt and cheese varieties, indicating that bioluminescence was a sensitive and rapid indicator of cellular viability for E. coli O157:H7. Survival of the pathogen, as indicated by this method, is possible in highly acidic environments even at refrigeration temperatures. This poses a potential hazard should postprocessing contamination occur.

Evaluation of the 3M Dry Medium Culture Plate (Petrifilm™ SM) Method for Determining Numbers of Bacteria in Raw Milk1

1984 ◽  
Vol 47 (10) ◽  
pp. 753-755 ◽  
Author(s):  
R. E. GINN ◽  
V. S. PACKARD ◽  
T. L. FOX
Keyword(s):  
Cold Water ◽  
Correlation Coefficients ◽  
Raw Milk ◽  
Water Soluble ◽  
Gelling Agent ◽  
Plate Count ◽  
Suitable Alternative ◽  
Standard Plate Count ◽  
Standard Plate ◽  
Indicator Dye

The 3M Company has developed a sample-ready system (Petrifilm ™ SM) for enumerating bacteria in milk and other food products. The testing unit consists of Standard Methods culture medium coated onto a base film and overlaid with a second film coated with a cold-water-soluble gelling agent and tetrazolium indicator dye. As such, the system is ready to accept samples of product. A pipette or 0.001-ml plate loop continuous pipetting syringe can be used for applying samples. In this study, both methods of sample addition were used and results compared with those of the Standard Plate Count (SPC) and standard Plate Loop (PL) methods for determining bacteria numbers in raw milk. In total, 108 samples were analyzed in duplicate by each of the four methods. The correlation coefficients (r) between the 3M-SPC and SPC, 3M-PL and PL, 3M-PL and SPC and PL and SPC were 0.946, 0.935, 0.941, and 0.974, respectively. Repeatability, as measured by mean log10 variance for duplicate determinations, was essentially the same for the four methods, and in all instances less than 0.005. The mean log10 differences between the SPC and 3M-SPC, and SPC and 3M-PL were, respectively, −0.177 and −0.168. The preceding statistical criteria suggest the Petrifilm™ SM method to be a suitable alternative to the SPC or the PL procedure.

scholarly journals Comparison of Probiotic Isolate Growth in Natural Culture with Various Carbon Sources

2021 ◽  
Vol 6 (2) ◽  
pp. 103-107
Author(s):  
Sitti Nur Ilmiah ◽  
Zaraswati Dwyana ◽  
Asadi Abdullah
Keyword(s):  
Carbon Sources ◽  
Plate Count ◽  
Standard Plate Count ◽  
Standard Plate

Probiotik merupakan mikroba hidup yang memberikan pengaruh menguntungkan pada inang karena dapat menyeimbangkan mikroba yang ada dalam saluran pencernaan menjadi meningkat. Pemanfaatan tersebut dapat memberikan pengaruh positif dan kesehatan bagi inang sehingga sangat baik untuk diaplikasikan. Pemanfaatan bahan alami dapat menekan biaya media tumbuh sehingga perlu penggantian media sintetik dengan media alami karena memiliki harga yang relatif lebih murah tetapi mengandung nutrien penting bagi pertumbuhan mikroba. Tujuan penelitian ini adalah untuk mengetahui pertumbuhan isolat probiotik berdasarkan lama waktu kutur dalam media alami yang mengandung sumber karbon berbeda. Pertumbuhan isolat probiotik dalam berbagai sumber karbon dilakukan melalui metode Standard Plate Count (SPC). Melalui metode SPC didapatkan jumlah koloni isolat G dari masing-masing media berupa kanji, sagu, dan dedak yaitu 2,3 x 108 Cfu/mL, 6,4 x 106 Cfu/mL, dan 4,3 x 106 Cfu/mL selama 48 jam; 2,6 x 108 Cfu/mL, 1,6 x 108 Cfu/mL, dan 1,0 x 108 Cfu/mL selama 96 jam; 4,6 x 108 Cfu/mL, 1,8 x 108 Cfu/mL, dan 1,2 x 108 Cfu/mL selama 144 jam. Hasil yang didapatkan menunjukkan bahwa isolat G mampu ditumbuhkan dalam media alami berupa kanji, sagu dan dedak.

Microbiological Quality of Shellfish-Growing Waters in Chesapeake Bay

1994 ◽  
Vol 57 (3) ◽  
pp. 229-234 ◽  
Author(s):  
TUU-JYI CHAI ◽  
TZYY-JAN HAN ◽  
RALPH R. COCKEY
Keyword(s):  
Escherichia Coli ◽  
Chesapeake Bay ◽  
Water Samples ◽  
Microbiological Quality ◽  
Geographic Area ◽  
Water Area ◽  
Fecal Coliforms ◽  
Plate Count ◽  
Standard Plate Count ◽  
Standard Plate

A total of 338 water samples were collected at 20 stations from three geographically shellfish-growing areas in Chesapeake Bay from May to September 1989. Samples were examined for standard plate count, total coliforms, fecal coliforms, Escherichia coli and coliphages. Salinity, dissolved oxygen and temperature varied slightly with the depth, season, and geographic area of water samples. The geometric means of standard plate count for the three areas were 135, 355 and 275/ml, respectively. The range of means of fecal coliform for these areas was from <3 to 93/100 mi. Escherichia coli counts were also low with a range of <3 to 93/100 mi and a mean of < 3/100 mi. The growing water area adjacent to cropland was found to have higher bacterial counts than those of the other two areas. Levels of male-specific phages were very low. Results indicate that shellfish-growing waters in all three areas were of satisfactory bacteriological quality.

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