• Journal of Animal Science and Technology
• /
• v.54 no.1
• /
• pp.43-49
• /
• 2012

This study was carried out to investigate the effects of age of laying hens and grade of shell abnormality on internal egg quality. At each week, 1,000 eggs were randomly selected from 21,000 eggs laid by Hy-Line hens (100,000 birds) aged from 56 to 62 wk. The samples were divided into normal and externally abnormal eggs by an official egg grader. Then, egg quality including egg weight, egg white height, Haugh unit and yolk color was evaluated from each normal and abnormal eggs. The production rate of externally normal and abnormal eggs was 81.22 and 18.78%, respectively. No difference found in the production rate by the increase of hen's age, but Haugh unit of eggs from hens of 60-wk-old was higher (p<0.05) than that of 56-wk-old. When the same age groups were compared, egg white height and Haugh unit were lower in eggs which were externally abnormal. When the grade of abnormality increased, egg white height and Haugh unit were decreased further (p<0.05). Among the externally abnormal eggs, malformation showed the lowest Haugh unit. In conclusion, the shell abnormality of eggs laid by hens aged 56 to 62 wk was closely related with internal egg quality. Therefore, the grading external egg quality in the present egg grading system is directly related with the internal egg freshness.

• Food Science of Animal Resources
• /
• v.33 no.5
• /
• pp.672-677
• /
• 2013

The aim of this study was to develop sample preparation method and evaluate the exact cholesterol content in egg and egg powder purchased from Korean markets, and to determine whether significant differences exist among various egg products, since a variety of products are available in Korean markets and there are no recent databases for cholesterol. To evaluate the cholesterol content in chicken egg sold in Korean local market, a simple method using non-heated saponification to determine cholesterol for emulsified foods was applied. The results of recovery for egg and egg powder were in a range of 92.4-105.0%, with a relative standard deviation between 1.1% and 2.8% by using gas chromatography-flame ionization detector. Therefore, the total cholesterol content in whole egg was estimated between 160.8 and 226.3 mg/egg (AV(average) $186.8{\pm}3.5$), which is similar or lower than previously reported levels. The value for cholesterol in egg powder was estimated between 2.94 and 3.49 mg/g (AV $3.23{\pm}0.15$). We suggested method that can be applicable to chicken egg and egg powder matrix as providing rapid and accurate determination of cholesterol in egg and egg powder. This information will be helpful for processed food producers for deciding food labels of cholesterol content.

• Food Science of Animal Resources
• /
• v.33 no.2
• /
• pp.239-243
• /
• 2013

Salmonella Enteritidis is responsible for causing foodborne diseases upon consumption of egg products. While cases of S. Enteritidis isolation from eggs have been reported in other countries, no such cases have previously been reported in Korea. In this study, we report the first isolation and identification of S. Enteritidis from domestically distributed eggs in Korea. Eggs were collected from eight countrywide grocery stores during different seasons between 2011 and 2012. Egg contents and washing solution of egg shells were incubated in buffered peptone water, and the enriched broth was further enriched in tetrathionate broth and Rappaport-Vassiliadis. The secondary enriched broth was streaked on xylose lysine desoxycholate agar. The suspected colonies were confirmed to S. Enteritidis by a biochemical test, serotyping, and PCR test. Genetic relatedness among the isolates was analyzed using Diversilab Salmonella kit. Three strains of S. Enteritidis were isolated from egg contents and egg shells collected from grocery stores of the Eumseong-city in the fall of 2011. All three stains showed resistance to chloramphenicol, streptomycin, nalidixic acid, and ampicillin by the disk diffusion method. In addition, the isolates showed more than 99% DNA homology, indicating that they were presumably identical strains. Therefore, there is a requirement to monitor and control against S. Enteritidis from eggs in Korea.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.1
• /
• pp.158-163
• /
• 2004

We investigated the usefulness of 2-alkylcyclobutanones as markers for irradiated eggs and egg products by comparing 2-alkylcyclobutanone concentrations in irradiated raw egg yolk, boiled egg yolk, and egg yolk powder. One method of detection radiation-induced 2-alkylcyclobutanones involves extraction fat from irradiated egg samples separating 2-alkylcyclobutanones by florisil column chromatography, and identifying GC/MS. 2-(5'-Tetradecenyl)cyclobutanone of 2-alkylcyclobutanones was high relatively in boiled egg yolk, but 2-dodecylcyclobutanone was high in raw egg yolk and egg yolk Powder. Concentrations of the radiation-induced 2-alkylcyclobutanones increased linearly with the irradiation dose. The radiation-induced 2-alkylcyclobutanones from egg samples at 0.5 kGy over and not detected at the non-irradiated samples. Therefore, these compounds could be used as marker of Post-irradiation for egg Products.

• Journal of Food Hygiene and Safety
• /
• v.30 no.2
• /
• pp.178-188
• /
• 2015

Microbial quality of baked egg products was evaluated by counting the levels of sanitary indicative bacteria (aerobic plate counts, coliforms, and E. coli), L. monocytogenes and Salmonella spp. at the critical control points (CCPs) of manufacturing process. In addition, the survival and growth of foodborne pathogens in various egg products (cheese, tuna, tteokgalbi, pizza omelets, baked egg, and steamed egg) were investigated at 4, 10, and $15^{\circ}C$. The contamination level of aerobic plate counts decreased from 4.67 log CFU/g at CCP 1 to 0.56 log CFU/g at CCP 3 in baked egg products. No coliforms and E. coli were detected at all CCPs. Although L. innocua and Salmonella spp. were identified at CCP 1, no L. monocytogenes and Salmonella spp. were detected in the final products. The contamination levels of aerobic plate counts and coliforms in egg strips and number of aerobic plate counts in Tteokgalbi omelet are higher than the microbiological standard of processed egg products. At $10^{\circ}C$, the growth of all pathogens was not prevented in omelet and baked egg, but the populations of S. Typhimurium and E. coli were reduced in steamed egg at $10^{\circ}C$, regardless of the presence of other pathogens. The growth of L. monocytogenes was faster than that of S. Typhimurium and E. coli in omelet. More rapid growth of S. Enteritidis than S. Typhimurium was observed in egg products, indicating the greater risk of S. Enteritidis than S. Typhimurium in egg products.

• Food Science of Animal Resources
• /
• v.44 no.2
• /
• pp.309-325
• /
• 2024

The consumption of meat has been increasing, leading to a dynamic meat and meat processing industry. To maintain the quality and safety of meat products, various technologies have been explored, including intense pulsed light (IPL) technology. Several factors affect the inactivation of microorganisms by IPL treatment, including light intensity (fluence), treatment duration, pulse frequency, and the distance between the lamp and the samples. Meat products have been studied for IPL treatment, resulting in microbial reductions of approximately 0.4-2.4 Log. There are also impacts on color, sensory attributes, and physico-chemical quality, depending on treatment conditions. Processed meat products like sausages and ham have shown microbial reductions of around 0.1-4 Log with IPL treatment. IPL treatment has minimal impact on color and lipid oxidation in these products. Egg products and dairy items can also benefit from IPL treatment, achieving microbial reductions of around 1-7.8 Log. The effect on product quality varies depending on the treatment conditions. IPL technology has shown promise in enhancing the safety and quality of various food products, including meat, processed meat, egg products, and dairy items. However, the research results on animal-based food are not diverse and fragmentary, this study discusses the future research direction and industrial application through a review of these researches.

• Korean Journal of Agricultural Science
• /
• v.42 no.3
• /
• pp.207-213
• /
• 2015

High-quality protein ingredients have been used in nursery diets, in spite of expensive ingredients, to minimize nutritional deficiency and disease problems. Recent dramatic increases in prices of protein products for nursery diets have exacerbated the challenge. Spray-dried egg may be a part of the solutions. Therefore, this review describes the value of spray-dried egg in nursery diets as a high-quality protein source. Spray-dried egg is egg by-product and is produced by only eggs without shell that are below the USDA Grade B standards. Spray-dried egg is an excellent nutrient source: 1) highly digestible, 2) excellent balance of amino acids, 3) rich content of fat, and 4) high metabolizable energy. These can be attributed to growth of nursery pigs. Beyond the provision of bioavailable nutrients, spray-dried egg also may provide specific physiological benefits. Spray-dried egg contains 1) immunoglobulin antibodies (IgY: IgG in egg yolk) that may attach to intestinal pathogens and excrete them and 2) lysozymes antimicrobial protein that can damage bacteria cell wall. Thereby feeding spray-dried egg may reduce concentration of intestinal pathogen and thus improve potential gut health or enteric disease resistance in nursery pigs. This is important for physiologically immature weaned pigs. Based on these benefits, spray-dried egg is believed to have the same benefits as spray-dried plasma protein and milk products in diets for nursery pigs. Therefore, it is suggested that spray-dried egg has a great potential as a valuable protein source in nursery diets.

• Food Science of Animal Resources
• /
• v.38 no.5
• /
• pp.901-911
• /
• 2018

Response surface methodology was used to study the effect of egg albumen (5-15 g), vegetable oil (5-15 g), and corn bran (5-15 g) on sensory and textural (firmness and toughness) quality of chicken nuggets cooked by the oven, steam, and microwave methods. The egg albumen and vegetable oil had a positive linear effect but corn bran had a negative linear effect at p<0.01 on sensory overall acceptability scores of nuggets. Firmness and toughness scores were increased significantly (p<0.01) with the increase in corn bran level in the formulation. The optimum level of egg albumen, vegetable oil, and corn bran were obtained and validated. Cooking methods also affected the sensory and textural quality of nuggets. Steam cooked nuggets had higher values of sensory scores than oven and microwave cooked nuggets. Oven cooked nuggets showed higher values of firmness and toughness than steam and microwave cooked nuggets. Results of this study suggest that emulsion based meat products can be enriched with dietary fiber source like corn bran without compromising the sensory and textural quality of the products.

• Journal of Food Hygiene and Safety
• /
• v.31 no.5
• /
• pp.342-348
• /
• 2016

The objective of this study was to compare the change of S. Enteritidis with S. Typhimurium populations in liquid egg products. S. Enteritidis or S. Typhimurium was inoculated into egg white and egg yolk and stored at 8, 10, 15, 25, and $35^{\circ}C$, respectively. In egg white, no growth of S. Enteritidis and S. Typhimurium was observed at 8, 10, 15, and $35^{\circ}C$, while both S. Enteritidis and S. Typhimurium in egg white stored grew more than 1 log CFU/ml after 50 hours storage at $25^{\circ}C$. In egg yolk, there was no growth of S. Enteritidis and S. Typhimurium at $8^{\circ}C$ but growth of both strains was observed at 10, 15, 25, and $35^{\circ}C$. Since growth of S. Enteritidis and S. Typhimurium was only observed in egg yolk, primary growth models for both strains were developed using modified Gompertz equation and then secondary models for lag time (LT), specific growth rate (SGR), and maximum population density (MPD) were developed as a function of temperature. At all temperatures, more rapid growth of S. Enteritidis than S. Typhimurium was observed in egg yolk, indicating the greater risk of S. Enteritidis than S. Typhimurium in egg products. In conclusion, the results indicate that temperature control less than $8^{\circ}C$ is very important to ensure safety of liquid egg products, especially liquid egg yolk.

• Korean Journal of Poultry Science
• /
• v.43 no.4
• /
• pp.229-233
• /
• 2016

This study was conducted to compare three commercially available egg testing devices for measuring egg quality. The devices used were a Laser-type (automatic), a Ultrasonic-type (automatic), and a Probe-type (manual). Fresh eggs weighing 60~68 grams were obtained from a commercial hen farm. Three trials were conducted. In Trial 1, a total of 50 eggs were successively analyzed by the three egg testing devices. In Trial 2, fresh eggs were successively analyzed by a combination of two egg testing devices. In Trial 3, a total of 600 eggs (weighing 60~68 grams) laid by same flock were selected, further divided into three sub-groups with a total of 200 eggs, and analyzed by an egg testing device. In Trials 1 and 2, no apparent difference was observed in egg weight between egg testing devices. However, albumin height was scored highest in the Ultrasonic-type egg tester followed by the Probe-type and Laser-type (Trials 1 and 2). Consequently, the Haugh unit was similarly altered. Yolk color was highest in the Laser-type egg tester followed by the Ultrasonic-type and Probe-type (Trials 1 and 2). When fresh eggs laid by a single flock were independently analyzed by three devices, egg weight did not differ, but albumin height and Haugh unit were higher (p<0.05) in the Ultrasonic-type egg tester than in the Probe-type or Laser-type testers. However, Laser-type testers produced higher (p<0.05) yolk color values than the Ultrasonic-type or Probe-type egg testers. In conclusion, the commercially available egg testing devices exhibited performance differences in measuring egg qualities, which warrants further consideration as to whether the magnitude of bias and precision between the devices could be acceptable in the egg grading system, especially when assessing eggs stored for certain durations.