scholarly journals Influence of the Initial Cell Number on the Growth Fitness of Salmonella Enteritidis in Raw and Pasteurized Liquid Whole Egg, Egg White, and Egg Yolk

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1621
Author(s):  
Silvia Guillén ◽  
María Marcén ◽  
Ignacio Álvarez ◽  
Pilar Mañas ◽  
Guillermo Cebrián
Keyword(s):  
Salmonella Enteritidis ◽  
Growth Parameters ◽  
Egg Yolk ◽  
Egg White ◽  
Cell Number ◽  
Initial Number ◽  
Initial Cell ◽  
Egg Products ◽  
Liquid Whole Egg ◽  
Whole Egg

Salmonella growth in egg and egg products has been widely studied, but there are still some aspects that are not fully known. The objective of this work was to study the influence of the initial cell number on the growth fitness of Salmonella Enteritidis in raw and pasteurized egg products. Growth curves of five Salmonella Enteritidis strains in raw and pasteurized egg products, starting from different initial numbers, were obtained and fitted to the Baranyi and Roberts model. The results revealed that lower initial numbers led to longer lag phases (λ) and lower maximum specific growth rates (μmax) in raw liquid whole egg. Similar results were observed in raw egg white (except for one strain). Conversely, no influence (p > 0.05) of the initial concentration on Salmonella growth parameters in raw egg yolk was observed. On the other hand, no influence of the initial number of cells on Salmonella growth fitness in commercial pasteurized liquid whole egg was observed. The results obtained demonstrate that the disappearance of this initial-dose dependency phenomenon was dependent on the intensity of the thermal treatment applied. Finally, the influence of the initial number was, in general, lower in pasteurized than in raw egg white, but large differences among strains were observed.

scholarly journals HOW DOES CRYOGENIC FREEZING AFFECT THE CALORIMETRIC PROPERTIES OF LIQUID EGG PRODUCTS?

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Hidas Karina Ilona ◽  
Ildikó Csilla Nyulas-Zeke ◽  
László Friedrich ◽  
Anna Visy ◽  
Judit Csonka ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Frozen Storage ◽  
Colour Change ◽  
Egg Yolk ◽  
Egg White ◽  
Dry Matter Content ◽  
Scanning Calorimetry ◽  
Egg Products ◽  
Liquid Whole Egg ◽  
Whole Egg

Eggs are widely utilized because of their high nutrient value, coagulating, foaming, emulsifying and sometimes even colouring or flavouring facilities in food manufacturing. Production of processed egg products shows an increasing trend. Frozen products belong to first processing, their shelf life can increase up to 1 year. By freezing, a large reduction in microbial loss can be achieved. But different undesirable processes can occur. The effect of freezing on animal cells is highly dependent on freezing parameters. It has a different effect on egg subtituents. Egg yolk undergoes a gelation process while proteins can denaturate. In our study pasteurized liquid egg products (liquid egg white, liquid egg yolk and liquid whole egg) were frozen by dripping into liquid nitrogen. After that, a 14-day frozen storage experiment was carried out at -18°C. Before freezing and on the 1th, 7th and 14th days of storage experiment pH, dry matter content, colour and calorimetric properties (denaturation temperatures and enthalpy of denaturation) with differential scanning calorimetry were tested. For statistical analysis, one-way ANOVA (α = 0.05) was employed. In our experiment, we found no significant change in calorimetric properties of liquid egg white after freezing, but significant decreasing of enthalpy and denaturation temperatures of liquid egg yolk and liquid whole egg was identified. In contrast, frozen storage had a decreasing effect in all these products. Freezing caused a clearly visible colour change in LEW, a visible change in colour of LWE and a very clearly visible change in colour of LEY. In case of LEW and LEY changes increased to clearly visible 14 days. In conclusion, our results show that frozen storage had a greater effect on liquid egg products properties than freezing in liquid nitrogen.

Behavior of Psychrotropic Pathogens Listeria monocytogenes, Yersinia enterocolitica, and Aeromonas hydrophila in Commercially Pasteurized Eggs Held at 2, 6.7 and 12.8° C.

1992 ◽  
Vol 55 (1) ◽  
pp. 8-12 ◽  
Author(s):  
JOHN P. ERICKSON ◽  
PHYLLIS JENKINS
Keyword(s):  
Listeria Monocytogenes ◽  
Yersinia Enterocolitica ◽  
Aeromonas Hydrophila ◽  
Egg Yolk ◽  
Egg White ◽  
Competitive Growth ◽  
Growth Responses ◽  
Egg Products ◽  
Spoilage Microflora ◽  
Whole Egg

Four commercially pasteurized liquid egg products were individually inoculated with Listeria monocytogenes, Yersinia enterocolitica, and Aeromonas hydrophila. They were unsalted whole egg blend, unsalted egg white, 5% NaCl whole egg blend, and 10% NaCl egg yolk. The inoculated samples and uninoculated controls were held at 2, 6.7, and 12.8°C (temperature abuse) for 14 d. Psychrotropic pathogen growth or survival risks in the unsalted and NaCl supplemented eggs were Y. enterocolitica > A. hydrophila > L. monocytogenes, and L. monocytogenes > Y. enterocolitica > A. hydrophila, respectively. Y. enterocolitica produced delayed (≥4 d) growth responses in unsalted eggs held at ≤6.7°C but was inhibited by ≥5% NaCl at all three holding temperatures. L. monocytogenes growth was prevented at ≤6.7°C in the unsalted and NaCl supplemented eggs. The organism rapidly increased in the temperature abused 5% NaCl whole egg blend. L. monocytogenes and A. hydrophila were inactivated in the unsalted egg white and NaCl supplemented eggs, respectively. Psychrotropic pathogen behavior was unaffected by the competitive growth of indigenous spoilage microflora including pseudomonads, Serratia spp., and NaCl tolerant micrococci. Properly refrigerated and hygienically handled pasteurized liquid eggs are microbiologically safe against a broad range of psychrotropic pathogen strains.

HEAT RESISTANCE OP STRAINS OP SALMONELLA IN LIQUID WHOLE EGG, EGG YOLK, AND EGG WHITE

1954 ◽  
Vol 19 (1-6) ◽  
pp. 451-463 ◽  
Author(s):  
W. W. OSBORNE ◽  
R. P. Straka ◽  
HANS LINEWEAVER
Keyword(s):  
Heat Resistance ◽  
Egg Yolk ◽  
Egg White ◽  
Liquid Whole Egg ◽  
Whole Egg

scholarly journals Effect of high hydrostatic pressure at 400 MPa on quality attributes of liquid egg products

2016 ◽  
Vol 5 (1-2) ◽  
pp. 148-152
Author(s):  
Adrienn Tóth ◽  
Csaba Németh ◽  
Réka Juhász ◽  
Ildikó Zeke ◽  
Salamon Bertold ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Egg Yolk ◽  
Rotational Viscometer ◽  
Egg Products ◽  
Thixotropic Behavior ◽  
Liquid Whole Egg ◽  
Whole Egg ◽  
One Way Anova ◽  
Shearthinning Behavior

Samples prepared from liquid egg yolk (LEY), liquid egg white (LEW) and liquid whole egg (LWE) were processed by high hydrostatic pressure (HHP) using different holding times (60, 180, 300, 420 and 600 s). The aim of our experiment was to examine how different holding times influences technofunctional attributes of liquid egg products. The color of samples changed after 60 s HHP treatment, but visible changes were evaluated just after 180­ 300 s. The pH of samples was stable, there were no significant changes caused by HHP (one-way ANOVA, a=0,05). The apparent viscosity was measured by a rotational viscometer as a function of shear rate. The shearthinning behavior of LEY and pseudopastic behavior of LEW and LWE were fitted well into HerschelBulkley model (with a satisfying correlation of R2 > 0.96). For the selected shearing rate, viscosity was measured in relation to shearing time. Thixotropic behavior of samples was increased by longer holding time of HHP treatments.

scholarly journals SalmonellaTyphimurium andSalmonellaSofia: Growth in and Persistence on Eggs under Production and Retail Conditions

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Catherine M. McAuley ◽  
Lesley L. Duffy ◽  
Nela Subasinghe ◽  
Geoff Hogg ◽  
John Coventry ◽  
...  
Keyword(s):  
Growth Rates ◽  
Salmonella Enterica ◽  
Egg Yolk ◽  
Maximum Growth ◽  
Egg White ◽  
Egg Products ◽  
Egg Shells ◽  
Retail Conditions ◽  
Whole Egg

Salmonellosis in Australia has been linked to eggs and egg products with specific serotypes associated with outbreaks. We compared attachment to and survival on egg shells and growth in eggs of twoSalmonellaserotypes, an egg outbreak associatedSalmonellaTyphimurium and a non-egg-associatedSalmonella entericassp. II 1,4,12,27:b:[e,n,x] (S. Sofia). Experiments were conducted at combinations of 4, 15, 22, 37 and 42°C. No significant differences occurred between the serotypes in maximum growth rates, which were significantly greater (P<0.001) in egg yolk (0.427 log10 CFU/mL/h) compared to whole egg (0.312 log10 CFU/mL/h) and egg white (0.029 log10 CFU/mL/h). Attachment to egg shells varied by time (1 or 20 min) and temperature (4, 22 and 42°C), withS. Typhimurium isolates attaching at higher levels (P<0.05) thanS. Sofia after 1 min at 4°C andS.Typhimurium ATCC 14028 attaching at higher (P<0.05) levels at 22°C. Survival on egg shells was not significantly different across isolates.Salmonellaserotypes behaved similarly regarding growth in egg contents, attachment to egg shells and survival on eggs, indicating that other factors more likely contributed to reasons forS.Typhimurium being implicated in multiple egg-associated outbreaks.

Development of an Effective Two-Step Enrichment Process to Enhance Bax System Detection of Healthy and Injured Salmonella Enteritidis in Liquid Whole Egg and Egg Yolk

2020 ◽  
Vol 83 (3) ◽  
pp. 397-404
Author(s):  
SHISHI HUANG ◽  
TAY BOON HUI ◽  
HYUN-GYUN YUK ◽  
QIANWANG ZHENG
Keyword(s):  
False Negative ◽  
Brain Heart Infusion ◽  
Egg Yolk ◽  
Target Cells ◽  
Detection Accuracy ◽  
Egg Products ◽  
Liquid Whole Egg ◽  
Inhibitory Components ◽  
Enrichment Process ◽  
Whole Egg

ABSTRACT The BAX system for pathogen detection has been highly accurate in a variety of food products. However, false-negative results have been reported for the detection of pathogens in liquid egg products because of failed pathogen resuscitation and the existence of inhibitory components. In this study, a short-time enrichment step was used to simultaneously resuscitate the target cells to the detection level and to dilute the inhibitory components to reduce detection interference. The MP medium (BAX system) enabled faster multiplication of healthy Salmonella cells than did buffered peptone water (BPW) in tested liquid whole egg and egg yolk. However, MP failed to resuscitate heat-injured cells even after 24 h of incubation. Therefore, MP was replaced with BPW as the enrichment broth for the BAX system. However, the use of BPW for a one-step enrichment was not effective for removal of PCR inhibitors in egg yolk, and unstable detection results were obtained. To improve detection accuracy, a second step of enrichment with brain heart infusion was added. This two-step enrichment process shortened the enrichment time to 14 h and greatly increased the number of samples in which the pathogen was detected during the same enrichment time, especially in the liquid egg yolk samples. The validation study revealed 100% diagnostic accuracy of the two-step enrichment process plus the BAX system. These results indicate that a two-step enrichment process added to the BAX system can improve the detection of pathogenic Salmonella in liquid egg products. HIGHLIGHTS

Review: Application of Pulsed Electric Fields in Egg and Egg Derivatives

2006 ◽  
Vol 12 (5) ◽  
pp. 397-405 ◽  
Author(s):  
F. Sampedro ◽  
D. Rodrigo ◽  
A. Martínez ◽  
G. V. Barbosa-Cánovas ◽  
M. Rodrigo
Keyword(s):  
Shelf Life ◽  
Electric Fields ◽  
Salmonella Enteritidis ◽  
Structural Changes ◽  
Pulsed Electric Fields ◽  
Egg White ◽  
Treatment Conditions ◽  
Quality Aspects ◽  
Liquid Whole Egg ◽  
Whole Egg

This work overviews works published on the application of pulsed electric fields (PEF) in egg and egg derivatives, grouped by subject, and arranged chronologically in terms of the factor studied (microorganisms, quality aspects, shelf life and structural changes in gel formation properties). The inactivation of microorganisms by PEF in egg is very considerable, 3.5 decimal reductions in egg white were achieved by PEF in Salmonella enteritidis, 5.5 log reductions of Listeria innocua by means of a synergistic effect of PEF and nisin in liquid whole egg, and 5.6 log reductions of Escherichia coli in beaten fresh liquid egg by PEF treatment applied continuously or discontinuously in five steps. The shelf life of PEF-treated fresh liquid egg was extended to 4 weeks in refrigeration, and quality (colour, viscosity and sensory attributes) was not affected by PEF treatment. PEF treatment did not cause notable changes in proteins in a solution of ovalbumin and dialysed fresh egg white. However, some structural changes and functional modifications were observed in fresh egg white as a result of PEF treatment. The texture and microstructure of gels were affected by the application of PEF, and therefore PEF treatment conditions in egg white must be optimised to minimise possible modifications.

Performance of Several Enrichment Media in the Isolation of Salmonellae from Liquid Egg Products

1984 ◽  
Vol 47 (3) ◽  
pp. 217-219 ◽  
Author(s):  
M. YDE ◽  
G. GHYSELS
Keyword(s):  
Comparative Study ◽  
Egg Yolk ◽  
Selective Enrichment ◽  
Egg Products ◽  
Liquid Whole Egg ◽  
Whole Egg

Ninety-seven samples of raw liquid whole egg and egg yolk were analyzed for the presence of Salmonella; 51 samples (52%) were found positive. A comparative study was conducted on the performance of seven selective enrichment procedures in the isolation of Salmonella from liquid egg products: selenite-cystine broth incubated at 37°C and 43°C, Muller-Kauffmann tetrathionate broth at 43°C, modified Rappaport medium RIO/100 and RIO/10 also incubated at 43°C, the experimental broth of Greenwood et al. incubated at 37° and 43°C. The best results were obtained with tetrathionate broth which detected 96% of all positive samples. Differences in the rate of isolation by the tetrathionate broth, selenite-cystine broth, modified Rappaport medium RIO/100 and the experimental broth of Greenwood et al., all incubated at 43°C, were not significant as determined by paired χ2 test. Minor results were obtained with selenite-cystine broth and the experimental broth of Greenwood et al., both incubated at 37°C. Modified Rappaport medium RIO/100 proved to be more efficient than RIO/10.

scholarly journals Two outbreaks of Salmonella enteritidis phage type 4 infection associated with the consumption of fresh shell-egg products

1989 ◽  
Vol 103 (1) ◽  
pp. 47-52 ◽  
Author(s):  
J.M. Cowden ◽  
D. Chisholm ◽  
M. O'Mahony ◽  
D. Lynch ◽  
S. L. Mawer ◽  
...  
Keyword(s):  
Environmental Sample ◽  
Egg Production ◽  
Salmonella Enteritidis ◽  
Phage Type ◽  
Egg Yolk ◽  
Egg White ◽  
The Other ◽  
Causative Organism ◽  
Epidemic Strain ◽  
Egg Products

SUMMARYIn 1988 there were two outbreaks of infection with Salmonella enteritidis phage type 4 in adjacent local authorities. The first affected 18 of 75 helpers and guests who attended a private function. Investigations revealed that home-made vanilla ice-cream containing uncooked eggs was the vehicle of infection and the causative organism was identified at the premises of the egg producer. The second affected 84 of 422 delegates attending a conference dinner, and 12 of 50 hotel staff at risk. A dessert made with lightly-cooked egg yolk and raw egg white was associated with infection, and the epidemic strain was cultured from the shell of an egg and an environmental sample from the producer's farm. It is of interest that one outbreak involved free-range and one battery-produced eggs, and that in one the vehicle was prepared at home and in the other in commercial premises. In neither incident was any deficiency in standards of egg production or catering practice discovered.

Occurrence of Campylobacter in Commercially Broken Liquid Egg in Japan

2010 ◽  
Vol 73 (3) ◽  
pp. 412-417 ◽  
Author(s):  
MIKI SATO ◽  
NOBUHIRO SASHIHARA
Keyword(s):  
Safety Concern ◽  
Egg Yolk ◽  
Egg White ◽  
Freezing And Thawing ◽  
Response Sensitivity ◽  
Freeze Thaw ◽  
Antibiotic Resistance Profile ◽  
Liquid Whole Egg ◽  
Contamination Levels ◽  
Whole Egg

Samples of unpasteurized liquid egg (whole egg, egg yolk, and egg white) and pasteurized liquid whole egg were collected from egg-breaking facilities in Japan and were tested for the presence of Campylobacter. Isolates recovered were tested for freeze-thaw response, sensitivity to antimicrobials, and heat resistance. Campylobacter was isolated from 27.9% of unpasteurized liquid whole egg samples and 36.0% of unpasteurized liquid egg yolk samples. No Campylobacter was isolated from unpasteurized liquid egg white or pasteurized liquid whole egg samples. The contamination levels of Campylobacter ranged from &lt;3 to 240/100 ml. Freeze-thaw response was tested by freezing and thawing liquid whole egg and egg yolk to examine whether those conditions influenced the survival rate. It was shown that freezing and thawing reduced Campylobacter counts. Sensitivity to all antimicrobials used in this study was observed in 47.6% of the isolates. The most predominant antibiotic resistance profile was similar to that of isolates from chicken. D55°C-values of 0.16 to 0.38 min and 0.47 to 0.84 min were determined for Campylobacter isolates in liquid whole egg and egg yolk, respectively. These values were lower than those reported for Salmonella. The very weak heat tolerance of Campylobacter indicated that it could be eliminated at the current legal pasteurization condition. There is no safety concern for commercially broken pasteurized liquid egg pertaining to Campylobacter contamination.

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