• 한국환경과학회지
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• 제29권10호
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• pp.1011-1014
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• 2020

The purpose of this study was to investigate the egg freshness and eggshell characteristics of old laying hens by adding sea urchin shell powder to the feed of such hens to achieve the objectives continuously pursued by environmental management, such as business profitability and waste resource utilization. A total of 90 Hy-Line Brown layers (66 weeks of age) were randomly divided into 2 treatments with 3 replicates, each of which consisted of 15 older layers, for 4 weeks. These treatments included a control (i.e., 0%) and 2% sea urchin shell powder. The 2% supplementation of sea urchin shell powder increased the Haugh unit (HU) at 2 and 4 weeks and eggshell strength at 4 wks compared to the controls (p<0.05). The HU at 0 weeks, eggshell thickness from 0 through 3 weeks, and eggshell strength at 0 and 2 weeks were not different between treatments (p>0.05). These results suggest that the addition of 2% sea urchin powder to the feed of laying hens improves egg freshness and eggshell strength in old laying hens.

• 한국가금학회지
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• 제43권1호
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• pp.31-38
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• 2016

Consumers demand fresh and high-quality eggs. Egg quality may be represented by shell color, shell weight, egg weight, shell thickness, shell density, albumen height, yolk color, albumen pH and viscosity. Various factors such as strain, age of hen, storage temperature, humidity, the presence of $CO_2$ and storage time affect egg quality. Therefore, we investigated the effects of storage time and temperature on egg quality to define the freshness of Korean market eggs. A total of 1,800 eggs were used for this experiment and were separated into 45 treatments with 40 eggs in each. The treatments were consisted of 15 storage periods (2 d to 30 d) and 3 storage temperatures ($2^{\circ}C$, $12^{\circ}C$, $25^{\circ}C$). Each egg was weighed and broken, and the height of the thick albumen, Haugh units (HU), egg shell color and yolk color were measured by a QCM+system. We also observed the physiochemical properties of eggs such as yolk pH, albumen pH and albumen viscosity. The egg weight, shell weight, albumen height, HU and albumen viscosity significantly decreased with increasing storage time and temperature. However, the albumen and yolk pH significantly increased with increasing storage period and temperature. The interaction effects between the storage period and temperature were significant for shell weight, shell density, egg weight, albumen height, HU, yolk color, yolk pH, albumen pH and albumen viscosity. In the analysis of the correlation with egg quality, the storage temperature exhibited a higher correlation coefficient than the storage period. In conclusion, storage time and temperature are the major factors affecting egg quality, but the storage temperature is a more sensitive determinant of egg quality deterioration compared with the storage period.

• 한국식품조리과학회지
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• 제32권5호
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• pp.619-626
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• 2016

Purpose: This study aims to provide important methods to increase egg usage eggs in communal food services, based on the knowledge and awareness of the dietician. Methods: A survey on 200 dieticians in various aspects, such as egg purchase, utility, importance of egg dishes and allergy awareness was conducted. Result: Dieticians' highest consideration in purchasing eggs were cost (41.5%) and food safety certification (41.0%); the 88.6% of purchases were general egg. The most inconvenient issues in the purchase were inability to confirm freshness (42.0%), frequent breakage (23.5%) and inconvenience in shell disposal (18.5%). During the process of cooking, cracking egg shells (49.5%) and disposal of shells (14.0%) were marked as the major inconveniences. When questioned on intention to purchase liquid and powder eggs to overcome the shell disposal inconvenience, 64% answered no, with distrust in food safety (44.5%) being the major concern. The frequency of using eggs as the main ingredient was 1~2 times per week, with 49.0%. Food service customers favored rolled omelet (36.7%) and steamed egg (20.6%), and the most used utensil was the frying pan (56.5%). When important factors in egg dishes, namely diverse menu, taste, nutrition, consumer satisfaction and allergic reaction were surveyed, most answered that all 5 factors were important. Conclusion: For increasing egg dish inclusions in communal food service, the safety assurance, increase in liquid and processed egg use, and supply of cooking utilities are necessary.

• 대한화학회지
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• 제49권6호
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• pp.531-536
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• 2005

• Journal of Animal Science and Technology
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• 제54권1호
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• pp.43-49
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• 2012

본 연구는 산란계의 주령 및 난각의 형태이상 및 이상 정도가 내부품질에 미치는 영향을 조사하기 위해 실시되었다. 동일 주령의 산란계 2계군에서 56주령부터 62주령 사이에 산란한 계란 21,000개 중 각 주별 1,000개를 무작위 추출하여 축산물품질평가사가 정상란과 형태 이상란을 구분하였다. 각각의 출현율과 할란검사를 실시하여 내부품질을 조사한 결과 전체적으로 정상란은 81.22%, 이상란은 18.78%의 출현율을 보였다. 주령의 증가에 따른 이상란의 출현율은 유의적인 차이를 보이지 않았으며(p>0.05), Haugh unit은 60주령이 56주령에 비해 높게 나타났으며 그 외에는 차이가 없었다. 동일 주령대를 비교했을 경우 난백고와 Haugh unit은 형태 이상란이 낮고 또한 이상의 정도가 심한 경우 더 낮게 측정되는 결과를 보였다(p<0.05). 특히 이상란 중 기형란의 난고와 Haugh unit이 현저하게 낮은 결과를 보여 이상란 중에서도 기형란이 내부 품질이 가장 낮게 판명되었다. 결과를 종합해 보면 56~62주령 산란계로부터 생산된 계란의 외형적 이상은 내부품질의 저하와 밀접하게 상관한다고 볼 수 있으며, 현 계란 등급판정 체계에서 외관판정은 신선도 평가에 근거가 될 수 있을 것으로 보인다.

• 한국유기농업학회지
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• 제24권1호
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• pp.115-122
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• 2016

The main purpose of the current study was to compare quality of eggs 1) produced from hens housed in battery cages vs. free range, 2) from young vs. old hens, and 3) tagged with the lowest vs. the highest price in a local franchised mart. The ages of hens, at which their eggs were used for the analysis of quality, were 70 weeks old in the experiment 1, 22 and 47 weeks old in the experiment 2, and were unknown in the experiment 3. Eggs were analyzed for weight, albumen height, Haugh unit, shell color, shell strength, shell thickness, shell weight, yolk color, yolk weight, and egg white weight. In the experiment 1, significant differences were detected between two housing systems in shell color, shell weight, yolk color, and yolk weight (P<0.05), but not in egg weight, albumen height, Haugh unit, shell strength, shell thickness, and egg white weight (P>0.05). Although egg weight was slightly but not significantly higher in battery cages by 2.2 g than in free range, yolk weight was significantly higher in battery cage (P<0.05). On the contrary, shell color was greatly increased in free range system by 68.5% compared with battery cage. In the experiment 2, there were significant differences between young and old hens in egg weight, albumen height, Haugh unit, shell strength, shell weight, yolk color and yolk weight (P<0.05). Egg weight, shell weight, yolk color and yolk weight were increased in old hens than young hens while albumen height, Haugh unit, and shell strength were decreased. In the experiment 3, egg weight, albumen height, Haugh unit, shell weight, and egg white weight were significantly higher in the highest priced eggs than the lowest ones (P<0.05), whereas shell strength and yolk color were lower (P<0.05) but shell color, shell thickness and yolk weight were not different (P>0.05). So, egg freshness was clearly higher in the highest priced ones than in the lowest (P<0.05). Due to the limited information on raising and husbandry of laying hens whose eggs were tested for egg quality in the current study, the present results should be cautiously interpreted while contributing to the future study as a basis in this field.

• 한국가금학회지
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• 제35권3호
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• pp.275-281
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• 2008

산란계 사료에 lycopene을 첨가 급여하여 생산된 계란의 난황 중에 전이된 lycopene의 함량을 급여 기간별로 확인하고, lycopene 함유 계란의 난황색, 난중, 난각 강도, 난황고, 난백고, 난황 직경, 난황 계수와 Haugh Unit(호우 유닛) 등 계란의 각종 품질 특성과 이들 계란의 장기 보존에 따른 품질의 변화상을 조사하여 다음과 같은 결과를 얻었다. 1. 결과 lycopene 처리군의 계란 중 lycopene 농도는 난황액 1 gram 당 각각 약 1.56 ${\mu}g$과 1.57 ${\mu}g$ 이었으며, 대조군의 계란에는 lycopene의 함량이 없는 것으로 나타났다. 2. 사양 시험 2주경의 처리군의 난황 중 lycopene 함량 수준(23.4 ${\mu}g$)은 4주경의 수준(23.6 ${\mu}g$)과 유사하였다. 즉, 동일수준의 lycopene 첨가 사료를 지속적으로 급여하여도 난황 내 lycopene의 함량은 급여 기간의 경과에 따라 누적적으로 증가되지 않는 것으로 나타났다. 3. Lycopene 첨가군의 난황색 (P<0.01)은 대조군에 비하여 유의적으로 높은 수치를 보였다. 이외에도 처리군간에 통계적 유의성은 인정되지 않았으나 lycopene 첨가군의 난황고(P<0.08), 난황 직경(P<0.19), 난각 견실도(P<0.19), 호우 유닛(P<0.34), 난백고(P<0.33)도 대조군에 비하여 다소 높은 수치를 보였다. 각 처리군간에 난중의 차이는 없는 것으로 나타났다. 4. 계란을 실온에서 4주간 보관시킨 후, 이들의 품질을 측정한 결과, Lycopene 처리군의 난황색(EYC)은 대조군에 비하여 유의적으로 높았으나(P<0.01), 그 이외의 항목에서는 유의적 차이가 없었다. 저장 4주 후의 첨가군의 난백고와 난황고는 대조군 보다 크고 난황 직경(EYD)은 대조군보다 작게 나타났다. 이 현상은 첨가군의 호우유닛 수치를 대조군보다 크게 하는 데 영향을 미친 것으로 추정된다.

• 동아시아식생활학회지
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• 제7권4호
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• pp.491-501
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• 1997

The purpose of this study was to investigate the storage and cooking of eggs in addition to the purchase of special eggs. This survey was tarried out through questionnaire and subjects were 429 housewives whose children were middle or high school students in Kyunggi-do and Inchon. Most housewives began to purchase special eggs one year ago. When housewives purchased special eggs, the first consideration was in order of nutrition, freshness, price and preference. The higher housewives' education level was, the higher they took nutrition into consideration. More than half of housewives replied that the proper package of special eggs was 10 eggs or more, and perceived that the period between producers of eggs and consumers was less than 5 days. Most housewives did the freshness test by checking roughness of shell surface or the interior quality of egg yolk and white after purchase. Also most housewives stored eggs in the inside rack of refrigerator door. Most housewives served dishes made from eggs more than 2 or 3 times per week and perceived that soft-boiled eggs are foods easy of digestion. These results suggested that it is necessary to supply fresh and nutritious eggs and to develop various dishes made from eggs for quickly-prepared meals.

• 한국식품영양과학회지
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• 제23권2호
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• pp.315-321
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• 1994

In order to prevent the postharvest decay and to promote the freshness retention of fruits and vegetables grapefruit seed extract(GFSE), natural microorganism control agent, was applied to the preservation of fresh fruits and vegetables. Freshfruits and vegetables treated with GFSE and stored in polyethylene film (0.1mm) at 1$0^{\circ}C$-15$^{\circ}C$ of natural low temperature low kept better qualities in color and texture than the GFSE -not- treated control. The treatment using GFSE ina 250ppm to 500ppm concentration seemed to be an effective one for the control of Botrytis cinerea isolated in red wine grapes. After 4 weeks of storage the firmness rate of cucumbers treated with the dilute GFSE was four times higher than that of non-treated ones. GFSE showed effective inhibitory action towards plant pathological bacteria and fungi which were involved in the decay of fruits and vegetables. Minimum inhibitory concentrations of GFSE towards them were in the range of 250ppm to 500ppm .Direct visualization of microbial cells and spores using electron microscopy showed microbial cells and fungal spores the function of which was destroyed by treating with the dilute solutions of GFSE. It was observed that GFSE would reduced disease damages and have bactericide & fungicide properties during the storage of such fruits and vegetables as egg plant, wild edible greens , kumquat, and kiwi fruit.

• 한국식품저장유통학회지
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• 제21권5호
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• pp.609-617
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• 2014

본 연구는 국내에서 유통되고 있는 계란의 유통 중 신선도를 예측하기 위하여 적정 품질지표를 선정하고자 수행되었다. 산란 직후 0, 10, 20 및 $30^{\circ}C$에서 저장하면서 중량감모율, 비중, 색도, 난황계수, 난백계수, Haugh unit(HU), pH 및 관능특성 변화를 조사한 후 각 품질특성과 관능적 기호도와의 상관관계를 분석하였다. 저장온도에 따른 중량감모율, 비중, 난황계수, 난백계수 및 HU와 기호도와의 상관관계는 모든 온도 조건에서 유의적인 상관관계를 나타내었다(p<0.05). 특히 중량감모율과 기호도와의 상관관계는 0, 10, 20 및 $30^{\circ}C$에서 각각 r = -0.78, r = -0.93, r = -0.95 및 r = -0.99로 난백계수와 기호도와의 상관관계는 r = 0.66, r = 0.89, r = 0.89 및 r = 0.93으로 그리고 HU와 기호도와의 상관계수는 r = 0.64, r = 0.92, r = 0.96 및 r = 0.98로 유의적으로 온도가 높을수록 높은 상관계수를 보였다(p<0.01). 반면에 색도와 pH는 각기 상이한 결과를 나타내어 품질평가 자료로 이용하기에는 추가 연구가 필요한 것으로 여겨진다. 따라서 모든 저장온도에서 관능적 기호도와 높은 상관관계를 나타낸 중량감모율, 비중, 난황계수, 난백계수 및 HU의 변화를 계란의 유통 중 신선도 예측을 위한 품질지표로 선정하여 적용하는 것이 적절한 것으로 판단되었다.