Control of Bacillus weihenstephanensis in Pasteurized Liquid Whole Eggs Formulated with Nisin

2021 ◽  
Author(s):  
SUBASH SHRESTHA ◽  
Upasana Hariram
Keyword(s):  
Food Poisoning ◽  
Bacillus Weihenstephanensis ◽  
Egg Products ◽  
Bacillus Spp ◽  
Odor Evaluation ◽  
Plate Counts ◽  
Liquid Whole Egg ◽  
Spore Forming Bacteria ◽  
Whole Egg ◽  
Time Point

Bacillus weihenstephanensis can grow at refrigeration temperature and cause food poisoning. It has been isolated from liquid whole egg products. The moderate heat used for pasteurization of liquid egg products is ineffective for killing spore-forming bacteria including Bacillus. Available predictive models and a pretrial study in broth suggested the potential for growth of Bacillus spp. under the tested conditions. Hence, hurdles such as storage of product below 4°C or use of preservatives would be needed to ensure the food safety of pasteurized egg products. This study evaluated the growth inhibition of B. weihenstephanensis in pasteurized liquid whole egg product formulated with 6.25 ppm nisin during storage at refrigerated and abuse refrigerated temperatures for a total 13 weeks, in three replicate trials. At day 0, the product had a pH of 7.52±0.29, while background microflora such as aerobic plate counts, presumptive B. cereus, and yeast and molds were <10 CFU/g. Product inoculated with target 2.5 log10 CFU/g of B. weihenstephanensis, stored at 4°C for 4 weeks and subsequently at 7 or 10°C for 9 weeks exhibited no growth in all three replicate trials.  Average counts reduced (p<0.05) by at least one-log10 in six weeks in all samples stored at either 7 or 10°C. Similarly, growth of total plate counts, presumptive Bacillus spp., yeast and mold counts was not observed in uninoculated controls stored at 4°C for 4 weeks and subsequently at 7 or 10°C for 9 weeks. Visual and odor evaluation performed at each sampling time point showed no abnormalities. This study assessed the efficacy of maximum allowed level of nisin for use in pasteurized liquid whole eggs and validated the inhibition of B. weihenstephanensis in the product for an extended shelf life of up to 13 weeks.

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.

Nisin Reduces the Thermal Resistance of Listeria monocytogenes Scott A in Liquid Whole Egg

1999 ◽  
Vol 62 (9) ◽  
pp. 999-1003 ◽  
Author(s):  
KELLEY P. KNIGHT ◽  
FRANCIS M. BARTLETT ◽  
ROBIN C. McKELLAR ◽  
LINDA J. HARRIS
Keyword(s):  
Heat Treatment ◽  
Listeria Monocytogenes ◽  
Logistic Equation ◽  
Glass Ampoule ◽  
Log Reduction ◽  
Egg Products ◽  
Current Minimum ◽  
Liquid Whole Egg ◽  
D Values ◽  
Whole Egg

D-values (decimal reduction times) and z-values (increase in temperature required for a 1-log change in D-value) for Listeria monocytogenes Scott A were determined in liquid whole egg with nisin (0 or 10 μg ml−1) and NaCl (0 or 10%) by a submerged glass ampoule procedure. Samples were plated onto nonselective agar at appropriate intervals, and D-values were determined using a modified biphasic logistic equation. Addition of NaCl increased D-values at all temperatures tested. The addition of nisin to unsalted liquid whole egg resulted in a rapid 4-log reduction in viable counts within the first hour. Nisin significantly (P ≤ 0.05) decreased D-values at lower (<58°C) temperatures in both unsalted and salted liquid whole egg but had little effect on the D-values at current minimum U.S. and Canadian pasteurization temperatures (60°C without NaCl; 63°C with NaCl). However, when nisin was added 2 h prior to heat treatment, D-values were significantly (P ≤ 0.05) reduced at these temperatures. Inhibitory levels of nisin were detected in the liquid whole egg postpasteurization. Nisin could have a favorable impact on the control of L. monocytogenes in pasteurized liquid egg products.

Bacteriological Standards for Perishable Foods

1952 ◽  
Vol 72 (4) ◽  
pp. 411-423 ◽  
Author(s):  
M. Ingram ◽  
J. Brooks
Keyword(s):  
Health Hazard ◽  
Egg Products ◽  
Egg Albumen ◽  
Liquid Whole Egg ◽  
Whole Egg ◽  
Spray Dried

Consideration is given to the bacteria found in naturally-clean, dirty, and washed hens' eggs, both fresh and stored ; and to the bacteriology of the most important egg products-liquid whole egg, frozen whole egg, spray-dried whole egg, and dried egg albumen. The bacteriological tests hitherto proposed for these products are discussed. The occurrence of salmonellas, which may cause a health hazard, is described together with the results of pasteurization treatments which offer a prospect of eliminating these bacteria.

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.

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.

Functional properties of pasteurised liquid whole egg products as affected by the hygienic quality of the raw eggs

LWT ◽  
2010 ◽  
Vol 43 (3) ◽  
pp. 436-441 ◽  
Author(s):  
Margherita Rossi ◽  
Ernestina Casiraghi ◽  
Laura Primavesi ◽  
Carlo Pompei ◽  
Alyssa Hidalgo
Keyword(s):  
Functional Properties ◽  
Hygienic Quality ◽  
Egg Products ◽  
Liquid Whole Egg ◽  
Whole Egg

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.

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