• Korean journal of food and cookery science
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• v.15 no.4
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• pp.377-381
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• 1999

This study was designed to observe the effect of the amount of egg and the specific gravity on the quality of sponge cake. There was a little difference of the moisture content by the specific gravity when the amount of egg was same. However, as the amount of egg was increased at the same specific gravity, the moisture content and baking loss was significantly increased(p<0.05). At 100% of egg amount, the largest specific loaf volume was gained at 0.55 of specific gravity, in the same way 150% at 0.45, 200% at 0.35, 250% at 0.45, The hardness of sponge cake was increased as the specific gravity was increased at the same amount of egg(p<0.05). The specific gravity which the lowest hardness was gained was 0.55 with 100% of the amount of egg, in th same way 0.45 with 150%, 0.35 with 200%. As the period of storage was longer, the increase of hardness was increased as the specific gravity went up at the same amount of egg(p<0.05). Therefore, in the case of sugar content 166%, the specific gravity with maximum specific loaf volume and minimum hardness was gained 0.55 at the amount of egg 100%, 0.45 at 150%, 0.35 at 200% and 0.35 at 250%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.957-965
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• 2013

This study simulated the egg vertical distribution of mackerel Scomber japonicus in Korean waters using general numerical models. All eggs were spawned naturally by raising broodfishes (May-June 2013), and the egg specific gravity was measured by a density-gradient column. CTD surveys provided environmental data (e.g., temperature and salinity) in May near Jeju Island, Korea. The egg specific gravity during the early stages ranged from 1.0203-1.0211. In general, the fertilized eggs showed a gradual decline in egg specific gravity until full development of the main organs, with a sudden increase just before hatching. Modeled egg vertical distributions were influenced more by wind speed than by egg buoyancy and vertical structure of the sea water. During calm and normal wind speeds, the eggs were distributed from the surface to 25-m depths. Under strong wind conditions (three times higher than the normal speed), the egg concentration on the surface decreased, and the egg distributional depth was deeper (~50 m).

• Korean Journal of Poultry Science
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• v.19 no.1
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• pp.1-12
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• 1992

This study was divided into experiment I(129g egg-albumen plus 150g sucrose) and experiment II(161g egg-albumen plus 150g sucrose) which were subdivided into groups treated with 0, 8.71, 17.43 and 26.149 egg yolk. These experiments were incubated in a shaking water bath(5$0^{\circ}C$) with a speed of 92(turnaround) per minute for a period of times. The pH and specific gravity were measured after 2, 4, 6, 8, 10 and 12 hour incubations. The results obtained were as follows： 1. The pH and specific gravity were steadily increased by shaking time, but variably was influenced by the amount of egg yolk and egg-albumen. 2. In the groups treated with egg-albumen, egg yolk, and sucrose of experiments I and II, pH was increased by the amount of egg-albumen in conjunction with shaking time, but specific gravity was decreased. 3. Ten hours after shaking maximum pH 8.60 was shown in the groups treated with 161g egg-albumen ： however, in ：he groups treated with 129g egg-albumen the maximum pH 8.39 was shown 12 hours after shaking. The different time exhibited maximum pH resulted from the amount of egg-albumen used. 4. The pH specific gravity were higher in the ,groups treated without egg yolk than in the groups with egg yolk. 5. In the experiment I which was added four levels of egg yolk to 1509 of sucrose and 129g of egg albumen, specific gravity(Table 2) had a high (r＝0.9692$^{* *}$) correlation with pH (Table 1) and the regression equation between specific gravity and pH (X) was Y＝0.050＋0.145x. 6. In the experiment II which was added four levels of egg yolk to 150g of sucrose and 161g of egg albumen, specific gravity(Table 4) had a high (r＝0.8963$^{* *}$) correlation with pH (Table 3) and the regression equation between specific gravity and pH (X) was Y＝0.294＋0.110X.10X.

• Journal of Sericultural and Entomological Science
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• v.20 no.2
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• pp.6-9
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• 1978

This experiment was attempted to investigate the effect of the specific gravity of silkworm eggs on the hatching and the practical hatching ratio depend upon six egg production companies for two silkworm races and their reciprocal crosses. 1. The hatching and the practical hatching ratio in the specific gravity of medium and heavy eggs were higher than in the specific gravity of light eggs. 2. Compare with Japanese or Chinese mother races each other, it was inclined that the former seems to be higher than the latter on the hatching ratio in the specific gravity of light and medium eggs, but the practical hatching ratio was high only in the specific gravity of light eggs. 3. Chinese mother races were different in the practical and the hatching ratio between the specific gravity of eggs. On the contrary in case of Japanese mother races were no difference for the hatching ratio but difference in the practical hatching ratio between the specific gravity of eggs. 4. On the egg production company, in case of the specific gravity of medium and light eggs, the hatching and the practical hatching ratio were high significance, but no difference in the specific gravity of heavy eggs.

• Korean Journal of Poultry Science
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• v.19 no.4
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• pp.197-204
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• 1992

This study was divided into experiment 1(191 g egg-albumen plus 150g sucrose) and experiment 2(222g egg-albumen plus 150g sucrose)which were subdivided into groups treated with 0, 8.71, 17.43 and 26.149 egg yolk. These experiments were incubated in a shaking water bath($50^{\circ}C$ ) with a speed of 92(turnaround) per minute (or a period of times. The pH and specific gravity were measured after 2, 4, 6, 8, 10 and 12 hours incubation. The results obtained were as follows ： 1. The pH and specific gravity were steadily increased by shaking time, but decreased by the amount of egg yolk. 2. In the groups treated with egg-albumen, egg yolk, and sucrose of experiments 1 and 2, PH was increased by shaking time and reached highest value at 10 hours shaking time. However, after 12 hours shaking time pH slightly decreased though not significantly. 3. In the experiment 1 and 2, specific gravity had a higher correlation with pH and the regression equation between specific gravity and pH (X) were Y＝0.1081x+0.272(r＝0.899n) and Y＝0.083X＋0.476(r＝0.825$^{* *}$), respectively.y.

• Journal of Food Hygiene and Safety
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• v.4 no.1
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• pp.29-36
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• 1989

In order to investigate the Storage time of chicken eggs, several physico-chemical tests from chicken eggs store at 5, 13 and 27$^{\circ}C$ were examined. Egg samples were collected from six poultry farms. Egg stored at 5$^{\circ}C$ based on the depth of air cell and specific gravity, were all acceptable until 17 days ; on the egg yolk coefficient and pH of the egg white and egg yolk until about 10 days. Egg stored at 13$^{\circ}C$, based on the depth of air cell. were acceptable by about 10 days of storage, but on the other physico-chemical tests by about 7 days. Egg samples stored at room temperature(about 27$^{\circ}C$) base on the depth of air cell, were acceptable by about 5 days of storage ; on the specific gravity by 4 days ; and on the egg yolk coefficient and pH of the egg yolk and egg white by 3 days. The results of this study showed that egg stored at 5$^{\circ}C$ were considered acceptable by 10 days of storage ; at 13$^{\circ}C$ by 7 days ; at room temperature (27$^{\circ}C$) by 3 days.

• Korean Journal of Poultry Science
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• v.23 no.1
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• pp.39-46
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• 1996

An experiment was conducted to investigate the effect of feeding split diets for a.m. and p.m. in laying hens on egg shell qualities, and to study the relationship among the methods of measuring shell quality with 480 ISA Brown layers during 32∼36, 52∼56 and 72∼76 wk of age, respectively. A total of 1,080 eggs were collected from 6 treatment groups in every laying period and weighed individually. Egg specific gravity, egg breaking strength, shell thickness and shell percentage of eggs were measured, and then correlation coefficients (r) and regression equations were calculated. By feeding the split diets for a.m. and p.m. differing in ME, CP, and Ca levels, and as the Ca level of the p. m. diet increased, eggshell qualities were improved(P<0.05). The correlation coefficient values indicate that shell percentage, shell thickness and egg specific gravity are highly correlated with the egg breaking strength(P<0.01).

• Korean Journal of Poultry Science
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• v.13 no.1
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• pp.15-21
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• 1986

An experiment was conducted for 14 days using 108 Manina Brown laying hens of 27 weeks of age to study the effects of dietary phosphorus levels on egg production, feed intake, feed efficiency, time of oviposition, specific gravity and weight of eggs. Hens were divided into 12 pens and each was assigned to one of the three treatments with 4 replications. Each hen was housed in individual cage. Birds on treatment 1 were fed a control diet (0.70% P) continuously and served as control. Hens on treatment 2 received a high phosphorus diet (HP: 2.54% P) between 06:00 and 10:00 and a low phosphorus diet(LP;0.33% P) for the rest of the day, Treatment 3 was fed HP diet for four hours immediately following oviposition and LP diet for the rest of the day. All diets contained a constant level of calcium (4.04 %). Results indicated that egg production, feed intake, feed efficiency were not significantly affected by the treatments. Hens in treatment 3 tended to lay earlier than those in treatments 1 (P〈.0.05 ) and 2 (P〈.0.01 ). There were no significant differences in egg weights among treatments. Egg specific gravity, however, was significantly (P〈0.01) improved by feeding HP diet for 4 hours immediately fellowing oviposition (treatment 3). There was no significant difference in the specific gravity between eggs from the control and treatment 2. There were found a linear relationship for egg weight and a quadratic relationship for egg specific gravity (P〈0.01) with time of oviposition. Specific gravity of eggs tended to be low as the egg weight increased.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.4
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• pp.399-405
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• 1991

The interaction of 4 dietary crude protein (13, 16, 19 or 22%) and 4 metabolizable energy (2600, 2800, 3000 or 3100 kcal ME/kg) levels on egg quality performances of Starcross layers were assessed between 245 and 275 days of age. The egg weight increased significantly with the increasing dietary protein and energy levels. But egg shape index, albumen index, yolk index, yolk dry matter, yolk protein, yolk fat, albumen protein and shell tickness were similar at all dietary protein and/or energy levels. The egg specific gravity and albumen weight increased but the yolk, weight, Haugh unit and albumen drymatter decreased with the increase of dietary protein levels and showed irregular trend with energy levels. The albumen dry matter and egg shell weight, however, were not affected by energy and protein levels. Simultaneous increase of protein and energy increased specific gravity, albumen index and shell thickness at a greater rate than that increased by the increase of protein or energy alone.

• Ocean and Polar Research
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• v.39 no.4
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• pp.257-267
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• 2017

Although Pacific mackerel (Scomber japonicus) is an important commercial species in Korea, its recruitment mechanism remains largely unknown. Diel vertical positioning of larvae in the water column, which is affected by their specific gravity and the surrounding water density, may help to provide an understanding on recruitment success through predator avoidance and prey availability. The specific gravity measurement on Pacific mackerel eggs and larvae would seem to be essential information necessary to learn about the transport process from spawning to nursery grounds, and consequently the recruitment success. Eggs were artificially fertilized, and larvae were fed with rotifer when their mouths opened 3-4 days after hatching. We conducted the experiment using a density gradient water column to measure the ontogenetic changes in specific gravity from fertilization to 10 days after hatching. Egg specific gravity was stable during most of the embryonic period, but a sudden increase to $1.0249g\;cm^{-3}$ happened just before hatching. However, the specific gravity of newly hatched larvae was much lighter ($1.0195g\;cm^{-3}$), and specific gravity tended to increase continuously after hatching. Comparison of specific gravity with seawater density reveals that eggs and newly hatched larvae can float in the surface layer of the ocean. For the later period of the experiment, the specific gravity showed a cyclic diel pattern: the highest in the evening while the lowest at dawn. The fullness of larval stomach may be responsible for the observed differences in specific gravity, because stomach fullness was lower (40-60%) at midnight, and higher (80-85%) in evening. The diel pattern of specific gravity might provide clues regarding how larvae match the diel vertical migration of prey organisms.