Factors Influencing Inactivation of Salmonella Enteritidis in Hard-Cooked Eggs

2000 ◽  
Vol 63 (1) ◽  
pp. 36-43 ◽  
Author(s):  
W. CHANTARAPANONT ◽  
L. SLUTSKER ◽  
R. V. TAUXE ◽  
L. R. BEUCHAT

The inside of a hen's egg, once considered sterile, is now known to occasionally harbor Salmonella Enteritidis. At least two recent outbreaks of salmonellosis in which Salmonella Enteritidis PT34 was involved have been associated with hard-cooked eggs. This study was undertaken to compare D56°C values of Salmonella Senftenberg 775W and six strains of Salmonella Enteritidis isolated from outbreaks associated with eggs. D56°C values for Salmonella Enteritidis in liquid egg yolk ranged from 5.14 to 7.39 min; the D56°C value for Salmonella Senftenberg was 19.96 min. The two PT34 strains from outbreaks associated with hard-cooked eggs did not exhibit significantly higher resistance to heat compared with two PT4 strains and one strain each of PT8 and PT13a. A PT4 strain and a PT34 strain of Salmonella Enteritidis were separately inoculated (107 to 108 CFU) into the yolk of medium and extra large shell eggs at 10 and 21°C, and survival was monitored using two cooking methods: (i) placing eggs in water at 23°C, heating to 100°C, removing from heat, and holding for 15 min (American Egg Board method) and (ii) placing eggs in water at 100°C, then holding for 15 min at this temperature. Within the 15-min holding periods, inactivation was more rapid using the method recommended by the American Egg Board compared with method 2. Within each cooking method, inactivation was most rapid in medium eggs initially at 21°C. The PT4 strain survived in yolk of extra large eggs initially at 10°C when eggs were held in boiling water 9 min using method 2. The final temperature of the yolk in these eggs was 62.3 ± 2°C. Of the two methods evaluated for hard cooking eggs, the American Egg Board method is clearly most effective in killing Salmonella Enteritidis in the yolk.

2011 ◽  
Vol 74 (12) ◽  
pp. 2031-2038 ◽  
Author(s):  
ELIZABETH C. P. RODRIGUES ◽  
MAURO C. L. SOUZA ◽  
SANDRO S. TOLEDO ◽  
CELSO G. BARBOSA ◽  
ELIANE M. F. REIS ◽  
...  

The goal of this study was to determine the effects of various levels of gamma irradiation on the phenotypic characteristics of 20 strains of Salmonella Enteritidis inoculated separately into specific-pathogen-free shell eggs. Bacterial strains were inoculated into egg yolks and exposed to 60Co radiation at doses of 0.49 to 5.0 kGy. The eggs were maintained at 25°C and analyzed for the presence of Salmonella on days 1, 2, 4, and 7, and the recovered Salmonella isolates were characterized biochemically. All strains were resistant to doses of 0.49, 0.54, 0.59, 0.8, and 1 kGy; colony counts were ≥105 CFU/ml of egg yolk except for one strain, which was detected at 96 h and at 7 days after irradiation at 1 kGy, with a population reduction of 2 log CFU/ml. For the other evaluated doses, 12 strains (60.0%) were resistant at 1.5 kGy and 7 strains (35.0%) were resistant at 3.0 kGy. Among all analyzed strains, 5.0 kGy was more effective for reducing and/or eliminating the inoculated bacteria; only two (10%) strains were resistant to this level of irradiation. Salmonella colony counts were significantly reduced (P < 0.01) with increasing doses from the day 1 to 7 of observation, when microbial growth peaked. Loss of mobility, lactose fermentation, citrate utilization, and hydrogen sulfide production occurred in some strains after irradiation independent of dose and postirradiation storage time. Increases in antibiotic susceptibility also occurred: seven strains became sensitive to β-lactams, two strains became sensitive to antifolates, and one strain each became sensitive to fluoroquinolone, phenicol, nitrofurans, tetracyclines, and aminoglycosides. The results indicate that up to 5.0 kGy of radiation applied to shell eggs inoculated with Salmonella Enteritidis at 4 log CFU per egg is not sufficient for complete elimination of this pathogen from this food matrix.


ZOOTEC ◽  
2016 ◽  
Vol 36 (2) ◽  
pp. 447
Author(s):  
Tiltje Andretha Ransaleleh

CHEMICAL COMPOSITION AND ORGANOLEPTIC CHARACTERISTICS OF PROCESSING BAT (Pteropus alecto) FRESH MEAT. Study was done to evaluate chemical composition and preference degree of the consumers on the processing bat meat compared with beef, chicken and cakalang fish using steam cooking method, flavor cooking and spicy cooking method. Chemical composition was analyzed by proximate analysis using procedures of the Association of Official Analytical Chemists. The organoleptic test was done by hedonic test. Data of the hedonic test were analyzed using Kruskal-Wallis method. To evaluate data distribution of the panelist respons on the sample test, the data were using plot graphic box. The hedonic scales were using 1 to 7. The variables used were including color, taste, flavor, tenderness and general acceptance. Results of proximate analyses of bat meat based on fresh meat indicated that water content was 67.21 percents and protein was 20.48 percents. Based on dry matter, the protein contents of bat meat, pork, chicken, and cakalang fish were 48.97 percents, 69.08 percents, 67.14 percents, and 69.41 percents, respectively. The water contents were 5.76 percents, 9.92 percents, 8.27 percents, and 9.90 percents, repsectively; the calcium (Ca) contents were also 10.62 percents, 1.09 percents, 1.36 percents, 1.38 percents, respectively; while Phosphor (P) contents were 1.46 percents, 0.69 percents, 0.66 percents, and 0.72 percents, respectively. Variance analysis for organoleptic test showed that meat type with different processing affected significantly on taste, color, flavor, tenderness and general preference of bat meat, beef meat, chicken meat and cakalang fish by steam cooking, chicken flavor, and spicy cooking methods. Conclusion, bat meat contained protein relatively lower than that in pork meat, chicken meat, and cakalang fish, but mineral contents were relative higher. Results of organoleptic test showed that preference degree of processing meat were higher on using spicy flavor. The specific test on taste, color, flavor, tenderness and general responsed showed relatively the same responses by the panelists.   Key word: Chemical composition, organoleptic test, processing bat meat


1973 ◽  
Vol 28 (7-8) ◽  
pp. 482-483
Author(s):  
S. De Boeck ◽  
T. Rymen ◽  
J. Stockx
Keyword(s):  
Egg Yolk ◽  

1968 ◽  
Vol 46 (8) ◽  
pp. 983-988 ◽  
Author(s):  
J. Z. Augustyniak ◽  
W. G. Martin

Two glycopeptides (A and B) were isolated from pronase-digested vitellenin, the protein moiety of the low-density lipoprotein of hen's egg yolk. Aspartic acid was the only N-terminal amino acid of both glycopeptides but only A contained N-acetylneuraminic acid. A contained 55% hexose (mannose), 14% hexosamine, 12% N-acetylneuraminic acid, 0.71% amide nitrogen, and its molecular weight was 2.3 × 103. The corresponding values for B were 64, 17, 0.0, 0.75, and 2.0 × 103. Chemical analyses showed that B (and probably A) occurs in vitellenin with the heteropolysaccharide group bound N-glycosidically via the β-amide group of an asparaginyl residue. The indicated structure is R∙(NH)Asp∙Thr∙Ser∙(Ala, Gly, Val)∙Ile, where R, the heteropolysaccharide group, contains 2 hexosamine and 8 hexose residues.


2001 ◽  
Vol 64 (6) ◽  
pp. 865-868 ◽  
Author(s):  
RICHARD K. GAST ◽  
PETER S. HOLT

Refrigeration of eggs is vital for restricting the multiplication of Salmonella enterica serotype Enteritidis contaminants, but differences between Salmonella Enteritidis strains or phage types in their survival and multiplication patterns in egg contents might influence the effectiveness of refrigeration standards. The present study compared the abilities of 12 Salmonella Enteritidis isolates of four phage types (4, 8, 13a, and 14b) to multiply rapidly in egg yolk and to survive for several days in egg albumen. The multiplication of very small numbers of Salmonella Enteritidis inoculated into yolk (approximately 101 CFU/ml) was monitored during 24 h of incubation at 25°C, and the survival of much larger numbers of Salmonella Enteritidis inoculated into albumen (approximately 105 CFU/ml) was similarly evaluated during the first 3 days of incubation at the same temperature. In yolk, the inoculated Salmonella Enteritidis strains multiplied to mean levels of approximately 103 CFU/ml after 6 h of incubation and 108 CFU/ml after 24 h. In albumen, mean levels of approximately 104 CFU/ml or more of Salmonella Enteritidis were maintained through 72 h. Although a few differences in multiplication and survival were observed between individual isolates, the overall range of values was relatively narrow, and no significant differences (P < 0.05) were evident among phage types.


2006 ◽  
Vol 69 (5) ◽  
pp. 1012-1016 ◽  
Author(s):  
TOSHIYUKI MURASE ◽  
KAZUHIKO FUJIMOTO ◽  
RUI NAKAYAMA ◽  
KOICHI OTSUKI

The invasive ability of Salmonella enterica serovars Enteritidis, Infantis, and Montevideo in eggs was examined. Strains of these serovars originating from egg contents, laying chicken houses, and human patients were experimentally inoculated (0.1-ml dose containing 78 to 178 cells) onto the vitelline membrane of eggs collected from specific-pathogen-free chickens and incubated at 25°C. The test strains were detected in 25 of 138 yolk contents by day 6, indicating the penetration of Salmonella organisms through the vitelline membrane. There were no significant differences in overall rates of penetration between serovars. The organisms were also detected in the albumen from 125 of 138 eggs tested by day 6. Growth to more than 106 CFU/ml was observed in 48 of the 125 albumen samples. An inoculum of 1,000 Salmonella cells was added to 15 ml of albumen at the edge of a petri plate. A 10-mm-diameter cylindrical well, the bottom of which was sealed with a polycarbonate membrane with 3.0-μm pores, was filled with egg yolk and placed into the albumen at the center of the dish, which was maintained at 25°C. Experiments were performed in triplicate with each strain. Salmonella organisms in all the albumen samples were detected by day 11. However, motility of the organisms toward the yolk was observed in only two dishes inoculated with the Salmonella Enteritidis strain from a human patient and in one dish inoculated with the Salmonella Infantis strain from liquid egg. The albumen samples obtained from the dishes inoculated with the Salmonella Enteritidis strain had high numbers of bacteria (>108 CFU/ml). The present study suggests that Salmonella organisms in egg albumen are unlikely to actively move toward the yolk, although deposition on or near the vitelline membrane can be advantageous for proliferation.


2019 ◽  
Vol 3 (2) ◽  
Author(s):  
C. A. Sepulveda ◽  
A. J. Garmyn ◽  
J. F. Legako ◽  
M. F. Miller

ObjectivesCooking meat using a clamshell grill has become common in university research settings due to speed, relative low cost, and acceptable repeatability. However, other cooking methods such as charbroiling and salamander grills have also become a popular method in the hotel and restaurant industry. The objective of this experiment was to evaluate the effect of different dry heat cooking methods on beef palatability across a range of USDA quality grades.Materials and MethodsA consumer panel (n = 288) was conducted at Texas Tech University. Strip loin steaks from four different USDA quality grades (Prime, upper 2/3 Choice, lower 1/3 Choice, and Select) were cooked using one of four cooking methods: electric clamshell grill (CLAM), flat top gas grill (FLAT), Charbroiler gas grill (CHAR), or Salamander gas broiler (SAL). After cooking to medium degree of doneness (70–72°C), steaks were cut into cubes (1.3-cm × 1.3-cm × steak thickness), and two cubes were served immediately to 6 predetermined consumers from each steak. Each consumer evaluated 8 samples, representing half of the 16 possible quality grades × cooking method treatment combinations. Consumers scored juiciness, tenderness, flavor liking, and overall liking using electronic ballots with the zero-point anchors labeled as extremely dry, extremely tough, dislike flavor extremely, and dislike overall extremely and the 100-point anchors labeled as extremely juicy, extremely tender, like flavor extremely, and like overall extremely. Also, consumers rated each sample as either acceptable or unacceptable for each palatability trait.ResultsThere were no interactions between the cooking method and quality grade for any of the palatability traits (P > 0.05). Steaks cooked on CHAR had greater (P < 0.05) flavor and overall liking scores, as well as a greater percentage of samples (P < 0.05) that were considered acceptable overall compared to the other cooking methods. Steaks cooked on FLAT were scored lower (P < 0.05) for tenderness and juiciness compared with all other cooking methods. Steaks cooked on CLAM, SAL, and CHAR were scored similarly for tenderness and juiciness (P > 0.05). Steaks cooked on FLAT were scored lower (P > 0.05) than CHAR and SAL for overall liking. Steaks cooked on CLAM had lower (P < 0.05) flavor liking scores than CHAR and SAL. Prime samples had greater scores (P < 0.05) than Low Choice and Select, which were similar (P > 0.05), for tenderness, juiciness, flavor liking, and overall liking, but Prime did not differ from Top Choice (P > 0.05) for any palatability traits.ConclusionThese results indicate cooking method had a significant impact on consumer palatability ratings, and those results were consistent across a range of quality grades. Even though these cooking methods are all classified as dry heat cookery methods, consumers in this study were able to detect differences in tenderness, juiciness, flavor liking, and overall liking. This may be due to increased cooking times or differing types of heat transfer possessed by the various cooking methods. These data suggest cooking steaks by CHAR resulted in the most desirable eating experience, and cooking steaks on FLAT and CLAM were less desirable. However, the low eating satisfaction of FLAT can be linked to low tenderness and juiciness, whereas CLAM liked less due to low flavor liking.


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