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.

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.

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

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 Comparison of different thawing methods effect on the calorimetric and rheological properties of frozen liquid egg yolk

2020 ◽  
Author(s):  
Karina Ilona Hidas ◽  
Csaba Németh ◽  
Anna Visy ◽  
Adrienn Tóth ◽  
László Ferenc Friedrich ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Dry Matter ◽  
Frozen Storage ◽  
Egg Yolk ◽  
Matter Content ◽  
Dry Matter Content ◽  
Freezing And Thawing ◽  
Scanning Calorimetry ◽  
Nutrient Value ◽  
Analyse Data

AbstractEggs are commonly used in the food industry because of their excellent nutrient value and also for their coagulating, foaming, emulsifying, colouring and flavouring properties. Manufacturers substitute shell eggs with processed egg products, such as liquid whole egg, liquid egg yolk or albumin. They have a shelf life of a few weeks, but freezing can increase it to 1 year. However, freezing causes gelation in case of egg yolk. This process is highly dependent on the conditions of freezing and thawing.In our study, raw liquid egg yolk was frozen and stored for 14 days at −18 °C. On days 1, 7 and 14 samples were thawed by two different methods. Denaturation temperature and enthalpy were investigated by differential scanning calorimetry. Besides, rheological properties were examined at 20 °C, Herschel–Bulkley model was fitted to flow curves of the examined samples. The dry matter content was also recorded during the experiment. Two-way ANOVA was used to analyse data.The results of the study showed that method of thawing had no significant effect on calorimetric and rheological properties and dry matter content. In contrast, freezing and frozen storage had a significant effect on denaturation enthalpy and rheological properties.

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.

Heat Resistance of Listeria monocytogenes Scott A and HAL 957E1 in Various Liquid Egg Products†

1995 ◽  
Vol 58 (11) ◽  
pp. 1211-1214 ◽  
Author(s):  
F. M. BARTLETT ◽  
A. E. HAWKE
Keyword(s):  
Listeria Monocytogenes ◽  
Egg Yolk ◽  
Death Time ◽  
High Temperature Short Time ◽  
Egg Products ◽  
Liquid Whole Egg ◽  
The Individual ◽  
Thermal Death Time ◽  
Short Time ◽  
Whole Egg

The thermal destruction of Listeria monocytogenes Scott A and HAL 957E1 (an egg isolate) was determined in five liquid egg products. The egg products used were liquid whole egg (LWE), liquid whole egg with 10% NaCl (LWEN), liquid whole egg with 10% sucrose (LWES), egg yolk with 10% NaCl (EYN), and egg yolk with 10% sucrose (EYS). Each of these products was inoculated with the individual strains of L. monocytogenes at initial populations of 106 colony-forming units (CFU)/ml and exposed to temperatures of up to 70°C for various periods of time from which thermal death time (TDT) curves were constructed. The Scott A strain tended to be more heat resistant than the egg isolate, HAL 957E1. The sensitivity of both strains to heating was influenced by the type of egg product in which they were suspended. The highest rates of kill were noted in LWE, while survival was best in those products supplemented with NaCl (LWEN and EYN). For the nonsalted products, time and temperature combinations equivalent to those required for the high-temperature short-time (HTST) pasteurization of liquid egg achieved 1.7 to 4.4 log-unit reductions of L. monocytogenes populations, while reductions for the salted products were only 0.2 to 0.6 log units. These results suggest that current HTST pasteurization conditions for liquid egg will not ensure a Listeria-free product, especially with products supplemented with NaCl.

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