• Food Science of Animal Resources
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• v.44 no.1
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• pp.74-86
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• 2024

Eggs that have been hard-boiled are frequently used as ready-to-eat food. Refrigerated and frozen storage of hard-boiled eggs causes issues, such as customer rejection owing to textural changes. The objective of this research is to ascertain how storage temperature affects hard-boiled eggs' alteration in texture over time. Medium-sized brown shell eggs were acquired from a local market, boiled at 100℃ for 15 min, and then stored at room temperature (25℃), refrigeration (4℃), and freezing (-18℃) conditions for 0, 12, 24, and 48 h. Fourier transform infrared spectroscopy (FTIR), texture profile, visual observation using a gemological microscope, free amino acid content, and color were measured. Freezing had a substantial impact on the eggs' hardness, gumminess, chewiness, and cohesiveness (p<0.05). The FTIR spectrums confirmed the textural changes in bonds of amide A (3,271 cm^-1), amide I (1,626.2 cm^-1), amide II (1,539.0 cm^-1), C=O stretch of COO^- (1,397 cm^-1), asymmetric PO₂^- stretch (1,240 cm^-1). Microscopic images confirmed structural changes in eggs stored at -18℃. The free amino acid content was lower in fresh and frozen eggs than in the rest (p<0.05). However, there was no discernible variation in the egg white's color when eggs were kept at 4℃ (p>0.05). Salmonella spp. was found exclusively in eggs kept at room temperature. In conclusion, hard-boiled eggs did not exhibit structural or chemical changes when stored at 4℃ for up to 48 h compared to freezing and room temperature conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.3
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• pp.306-312
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• 1986

Demonstration of the highly positive correlation between blood cholestrol levels and heart disease has made consumers wary of the fats in meat, milk and eggs. The egg, as perhaps the single largest common source of cholesterol, has been cited by many members of the medical and scientific world as a food contributing to heart disease. In light of decreasing per capita egg consumption and continuing dietary egg cholesterol controversy, many researchers have focused their efforts on egg nutrition. The results reported, however, are often contradictory. In spite of the disputable scientific evidence, the egg has been labelled (erroneously) as a highly cholesterogenic food. The objective of this presentation is to present a general picture of the problem and discuss our laboratory findings relevant to the problem. An isotope technique was utilized to incorporate $^{14}C$-cholesterol into egg yolk lipoproteins and study the metabolic fate of dietary ovo-cholesterol in rats. Two hundred and fifty micro-curies of 4-$^{14}C$-cholesterol, emulsified in corn oil, were orally administered to five Single Comb White Leghorn laying hens. Eggs were collected, hard-boiled, and the hot dried egg yolk powder (HEY) was prepared. Total radioactivity excreted via feces was determined. The rat groups fed egg yolk powder excreted more than 95% of the ingested ovo-cholesterol, whereas the rat chow group excreted only 47%. No difference was observed between HEY and CEY treatments. Therefore, an unknown lipid factor present in egg folk accelerates cholesterol turnover rate and excretion via feces.

• Korean Journal of Poultry Science
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• v.20 no.3
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• pp.125-131
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• 1993

This study was performed to find the desirable conditions for processing salted hard-boiled egg without cracking egg shell in NaCl solution under pressure. Among the many factors affecting saltiness of the shell egg, concentration of NaCl solution(0~40%), different salting time(0~45h) and salting pressure (0~4.5kg/$\textrm{cm}^2$) were employed to identify the permeability of NaCl into shell egg at ambient temperature. The saltiness of the shell egg was proportionally risen as concentration of NaCl solution, salting time and pressure increased. The most desirable saltiness was observed at the 0.70~1.00% of NaCl in albumen and 0.40~0.45% in yolk, Besides the saltiness, sensory evaluation of the shell egg were carried out to evaluate the quality of the salted shell egg. The effect of various concentration of NaCl solution, salting time and pressure on sensory scores of hard-boiled salted eggs showed that 20~40% of NaCl solution, 12~20 h of salting time, 3~4.5 kg/$\textrm{cm}^2$ of salting pressure were proper conditions for processing the product. These results indicate that the desirable condition to get salted hard-boiled shell egg were ; 30% of NaCl solution, 16h of salting time and 4.0kg/$\textrm{cm}^2$ of salting pressure.

• Journal of the Korean Society of Food Culture
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• v.26 no.5
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• pp.455-467
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• 2011

The main purpose of this study was to survey the various kinds of recipes for pheasant found in seventeen Korean cookbooks published from the 1800's to the 1990's. There were 95 pheasant recipes found in the literature which could be classified into three major groups: cooking with moist heat, cooking with dry heat, and other. The three major groups were then broken down into thirteen smaller groups. A detailed look at the frequency of terms in each recipe shows that Gui Sanjeok (grilled Korean shish kebabs) appears 24 times, Guk Tang and Jeongol (soup and stew) 23 times, Kimchi (fermented cabbage) 11 times, Po (jerky) 9 times, Jorim (boiled in soy sauce) 7 times, Jjim (steamed) 6 times, Bokeum (stir-fried) 5 times, Twigim (deep-fried) 3 times, Buchim (fried) 2 times, Jigae jijim (stewed) 2 times, and Jang (paste), Myeon (noodles), Gooum (boiled) and Yeot (Korean hard taffy) 1 time each. The main ingredient is always the pheasant. We investigated the use of the whole pheasant cooked, how to slice and tenderize pheasant meat, use the meat only, or use only certain parts. Depending on the characteristics of cooking recipes, pheasants with thin, soft bones and organs were investigated for cooking. Substituted materials were used for a few of the vegetables, meat, and seafood in the recipes, and seem to go well together. Garnishes used included pine nut powder and fried eggs. Seasoned salt, soy sauce, pepper, sesame, sesame oil, chopped onion, garlic, and ginger were also reported to have been used.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.565-569
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• 2003

The objective of this experiment was to determine the effects of different levels of refined cod liver oil (RCLO) on laying performance, n-3 polyunsaturated fatty acids composition (n-3 PUFAs) and the organoleptic evaluation of duck egg yolks. A total of 180 30 wk old laying Tsaiya ducks, at the beginning of peak production, were allotted into 6 treatments with 3 replicates each. Ducks were fed one of the 6 experimental diets, supplemented with 2% tallow (control) and graded levels of RCLO at 2, 3, 4, 5, and 6% to a corn-soybean diets, respectively, for 6 wks. All of the experimental diets were formulated to be both isocaloric and isonitrogenous. Feed and water were supplied ad libitum throughout the experimental period. The results indicated that the RCLO supplementation levels did not affect (p>0.05) egg production, egg mass, feed intake, feed efficiency or body weight change. Egg weight was the lightest when the ducks received the 6% RCLO diet. The eicosapentaenoic acid, docosahexaenoic acid, and total n-3 PUFAs contents in the yolks increased with increasing RCLO supplementation. The taste and general acceptability of the hard-boiled eggs were not significantly different among the treatments. However, a fishy flavor was much higher when ducks were fed diets supplemented with 5% and 6% RCLO diets.

• Journal of the Korean Dietetic Association
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• v.11 no.3
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• pp.320-330
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• 2005

The purpose of the study was to assess students’preferences on vegetarian menus served at middle and high schools. Four school food service programs that served primarily vegetarian menus were located in Seoul, Kyunggi, Kangwon, and Choongnam provinces. A total of 100 menu items frequently served at the schools were identified. Students participating in the school meals programs were asked to assess their preferences of the menus using a 5-point Likert-type scale(1 : very dislike - 5 : very like). Excluding responses with significant missing data, usable responses were 659. Statistical analyses were performed with descriptive statistics, t-tests, and one-way analysis of variance. Menu items of the highest preference scores included kimchi stew, stir-fried kimchi, nangmyon(cold noodles), fried rice and kimchi, miso stew, soft tofu stew, and hard-boiled quail eggs in soy sauce. By menu category, one-dish foods(3.97) were the most preferred and muchim and namul were the least preferred. Female students showed higher preferences on kimchi, steamed items(jjim), stir-fried items, namul, and muchim than male students; middle school students’preference scores were higher than those of the high school students in most menu categories. The menu preference is known as one of the most important factors determining students’food consumption and satisfaction with school food service. Dietitians working at school food service programs that serve primarily vegetarian menus should provide students with nutrition education on proper food selection and focus their efforts on developing new recipes using various vegetables and preparation methods to improve students’food consumption and menu preference.