• Food Science of Animal Resources
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• v.41 no.6
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• pp.1049-1059
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• 2021

The objective of this study was to evaluate the nutritional content of bullfrog meat from different parts of the animal, including fore-chest, thigh and calf. Bullfrog meat was found to be a rich source of proteins, essential amino acids and minerals, but with a low fat content, compared with other aquatic meat products. There was no significant difference (p>0.05) between thigh and calf in mineral content (K, P, Na, Mg, Ca, Zn, Fe, Cu, and Mn), but the contents of K, P, and Mg were higher in thigh and calf than in the fore-chest (p<0.05). The salt-soluble, water-soluble and insoluble protein bands in sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis, from fore-chest, thigh and calf were similar, with the most abundant bands being 35 kDa (salt-soluble protein), 35-48 kDa (water-soluble protein) and 48 kDa (insoluble protein). The results showed that the insoluble protein content in the fore-chest meat was higher than that in the thigh meat and calf meat, but the salt-soluble protein fraction was the most abundant in thigh meat. These results showed that the nutrients in different parts of bullfrog meat were different.

• Animal Bioscience
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• v.34 no.4
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• pp.539-545
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• 2021

Objective: Endometritis is a major disease, that causes infertility in cattle, and is usually categorized as clinical or subclinical endometritis (SCE). The nutritional condition during the dry period is important for recovery after the last stage of the lactation period, and for postpartum production and reproduction. This study aimed to clarify the relationship between nutritional and metabolic characteristics in the dry period, and the risk of postpartum SCE. Methods: Multiparous Holstein dairy cows (n = 25, raised in a tied stall) were used. Endometrial cytological analysis was performed around 30 days post-partum, with 5% to 14% polymorphonuclear (PMN) as a cut-off point to define SCE. Serum levels of glucose, non-esterified fatty acids, β-hydroxybutyric acid (BHBA), blood urea nitrogen, total cholesterol, aspartate aminotransferase, γ-glutamyl transpeptidase, calcium, phosphorus, and magnesium were measured in the cows at the dry period to evaluate energy status, protein metabolism, and mineral metabolism. Results: The incidence of SCE in the cows was 60.0% (n = 15/25) and the mean PMN% in postpartum cows diagnosed as SCE was 8.05%±2.6%. Overall, 17 and 8 samples were collected from the cows in the far-off and close-up periods, respectively. The serum concentration of BHBA in the far-off period and serum glucose concentration in the closeup period were correlated with postpartum PMN% (r = 0.62, p<0.01; r = -0.74, p<0.05, respectively). Serum levels of calcium and magnesium in the dry period were associated with the incidence of postpartum SCE (healthy vs SCE cows, p<0.05). Conclusion: Blood levels of glucose, BHBA, calcium, and magnesium in dry periods could be useful parameters for predicting the risk of postpartum SCE. The present study also suggests that management in the close-up period is essential for promoting recovery from calving fatigue.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.1
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• pp.83-93
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• 2021

NASA has a plan for the Artemis manned lunar mission in 2020. In 2030s, not only America but also other countries are considering to prepare for human to stay on the Moon at least for a month and necessary technology is currently being developed. With this plan, the mostly considered thing is lunar in-situ resource utilization. The most essential resources could be water and oxygen for sustain human life on the Moon. These resources are not supposed to be brought from the Earth, and it is economically sensible if they are obtained from the lunar surface. Because oxygen can be used as both oxidizer and propellent when a rocket departs from a lunar base directly to Mars, technology for extraction method of oxygen resource and its utilization has been being developed worldwide. This paper introduces oxygen distribution on the Moon and major oxygen extraction methods.

• International Journal of Industrial Entomology and Biomaterials
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• v.43 no.2
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• pp.85-93
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• 2021

Silkworm pupae have been utilized as a food source and have high-quality proteins and fatty acids. However, studies on the nutritional composition of pupae according to their variety, developmental stage, and sex have not been conducted. In this study, the nutritional composition of four Korean silk varieties (Baegokjam, BG; Goldensilk, GS; Juhwangjam, JH; and YeonNokjam, YN) were analyzed according to developmental stage and sex. The main ingredient of the pupa was protein, and the protein levels were higher in females than in males. Fat levels were high in males and increased in YN and GS during the late stage but decreased in BG. Fiber content rapidly increased in the late stages, and the lowest content was observed in BG. The pupae contained all essential amino acids, which were detected at higher ratios in females with a high protein content. Fatty acids had a different predominance depending on the variety. Oleic acid level was high in BG, linoleic acid and linolenic acid levels were high in GS, and palmitic acid and stearic acid levels were high in JH. In the mineral analysis, zinc was dominant in BG, whereas calcium and iron levels were relatively low. Zinc level was low in GS, and calcium and magnesium levels were high in JH. Potassium, sodium, magnesium, and phosphorus levels were low in YN. The silkworm pupae showed differences in components according to their variety, sex, and developmental stage; therefore, selecting a variety suitable for its purpose is necessary.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.91-101
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• 2022

In this study, we analyzed the compositional characteristics of Melosira nummuloides mass-cultured using Jeju lava seawater. M. nummuloides showed the highest growth rate when cultured for 14 days at 17-20℃ and 15,000 lx. Proximate composition of raw-material (RM) and freeze-dried M. nummuloides (FM) showed high ash content (65-72%), while ethanol-extracted M. nummuloides (EM) had low ash and high lipid contents. The predominantly occurring mineral, Si, was 334 g/kg in RM and 269 g/kg in FM, but EM contained only 1.97 g/kg. The ratio of essential amino acids was similar in RM (38.93%) and FM (36.89%) lower in EM (17.83%), but branched chain amino acids required for muscle metabolism was high (63.40%). The polyunsaturated fatty acids of EM (34.74%) was 11% more than that in RM (23.81%), and the ratio of omega-6 to omega-3 fatty acids was 1:3.6. Furthermore, the concentration of total chlorophyll was higher by 5.15 times (62.32 mg/g) and that of fucoxanthin by 7.06 times (11.02 mg/g) in EM than in RM (12.11, 1.56 mg/g, respectively). The mass cultivation and filtration of M. nummuloides using lava seawater has high prospects of commercialization as a competitive bio silica, cosmetic and healthy functional food material.

• Journal of Animal Science and Technology
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• v.63 no.6
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• pp.1386-1396
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• 2021

Copper is an essential mineral for pigs, thus it is used as a feed additive in the forms of copper sulfate. Therefore, this study aimed at characterizing the fecal microbiota shifts in pigs as fed by different forms of copper supplementation. 40 growing pigs aged 73 ± 1 days with an average weight of 30.22 ± 1.92kg were randomly divided into 5 groups. The control group (CON) fed with basal diet, while treatment groups were fed a basal diet supplemented with 100 ppm/kg of copper sulfate (CuSO₄), Cu-glycine complex (CuGly), Cu-amino acid complex (CuAA), and Cu-hydroxy(4methylthio)butanoate chelate complex (CuHMB) for 28 days of trial, respectively. The data presented the comparison between inorganic and organic copper supplementation through gut microbiota in growing pigs. Alpha and Beta diversity anaylsis resulted in copper supplementation did shifted gut microbioal community structure. At the phylum level, Firmicutes and Bacteroidetes were the most abundant phyla at all times regardless of treatment. At the genus level, the relative abundances of Prevotella, Lactobacillus, Megasphaera, and SMB53 of the CuGly and CuHMB groups were significantly higher than those of copper sulfate and basal diet groups. Overall, this study may provide the potential role of organic copper replacing inorganic copper, resulting in increased beneficial bacteria in the pig gut.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.247-247
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• 2023

Coastal lagoons play a crucial role in water exchange, water quality, and biodiversity. It is essential to monitor and understand the dynamics of hydrogeochemistry in lagoon water and its groundwater to preserve and sustainably manage the groundwater-dependent ecosystems like coastal lagoons. This study investigated the spatial and temporal hydrogeochemical characteristics of coastal lagoon (Songjiho) and groundwater on the east coast of Korea. The concentrations of major ions, water isotopes, and nutrients (nitrogen and dissolved organic carbon) in lagoon water and groundwater were periodically monitored for one year. The study revealed that major ions and total dissolved solids (TDS) concentration were higher at deeper depths of aquifers and closer to the coastal area. The hydrogeochemical characteristics of coastal lagoon and groundwater chemistry were classified into two types, Ca-Mg-HCO₃ and Na-Cl, based on their spatial location from inland to coastal area. Moreover, the hydrogeochemical characteristics of coastal lagoons and groundwater varied significantly depending on the season. During the wet season, the increased precipitation and evaporation lead to changes in water chemistry. As a result, the total organic carbon (TOC) of coastal lagoons increases during this season, likely due to increased runoff by rainfall whereas the variation of chemical compositions in the lagoon and groundwater were not significant because there is reduced precipitation, resulting in stable water levels and during the dry season. The study emphasizes the impact of spatial distribution and seasonal changes in precipitation, evaporation, and river discharge on the hydrogeochemical characteristics of the coastal aquifer and lagoon system. Understanding these impacts is crucial for managing and protecting coastal lagoons and groundwater resources.

• Nutrition Research and Practice
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• v.17 no.2
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• pp.257-268
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• 2023

BACKGROUND/OBJECTIVES: Zinc is an essential trace mineral which is important for the growth and development of the human body and immunological and neurological functions. Inadequate zinc intake may cause zinc deficiency with its adverse consequences. In this study, we aimed to estimate the dietary zinc intake levels and sources among Koreans. SUBJECTS/METHODS: For this secondary analysis, we obtained data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2016-2019. Individuals aged ≥ 1 yr who had completed a 24-h recall were included. The dietary zinc intake of each individual was calculated by applying data from a newly developed zinc content database to the KNHANES raw data. We also compared the extracted data with the sex-, age-specific reference values suggested in the Korean Dietary Reference Intakes 2020. The prevalence of adequate zinc intake was then evaluated by the proportion of the individuals who met the estimated average requirement (EAR). RESULTS: The mean zinc intake of Koreans aged ≥ 1 yr and adults aged ≥ 19 yrs were 10.2 and 10.4 mg/day, equivalent to 147.4% and 140.8% of the EAR, respectively. Approximately 2 in 3 Koreans met the EAR for zinc, but the zinc intake differed slightly among the different age and sex groups. In children aged 1-2 yrs, 2 out of 5 exceeded the upper level of intake, and nearly half of the younger adults (19-29 yrs) and the elders (≥ 75 yrs) did not meet the EAR. The major contributing food groups were grains (38.9%), meats (20.4%), and vegetables (11.1%). The top 5 food contributors to zinc intake were rice, beef, pork, egg, and baechu kimchi, which accounted for half of the dietary intake. CONCLUSION: The mean zinc intake among Koreans was above the recommended level, but 1 in 3 Koreans had inadequate zinc intake and some children were at risk of excessive zinc intake. Our study included zinc intake from diet only, thus to better understand zinc status, further research to include intake from dietary supplements is needed.

• Food Science and Preservation
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• v.13 no.3
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• pp.375-381
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• 2006

This study was carried out to analyze the nutritional component of Lepista nuda in order to estimate its nutritional and functional values. The content of moisture were $90.90{\pm}0.09%$ carbohydrate $4.34{\pm}0.07%$, crude protein $3.70{\pm}0.03%$, ash $0.55{\pm}0.04%$, and crude fat $0.47{\pm}0.01%$, respectively The reducing sugar was $636.17{\pm}7.50mg$. Total amount of free sugar was 97.32 mg, which were mainly composed of galactose (51.98 mg) and trehalose (22.48 mg). In the results of mined analysis, the content of K was the highest as $103.10{\pm}0.18mg$, followed by $56.01{\pm}0.20mg$ of Mg. The total content of hydrolyzed amino acid was 310.39 mg which consist of essential amino acids including valine (25.40 mg), leucine (22.52 mg), lysine (21.34 mg) and 198.89 mg of non-essential amino acids including glutamic acid (60.72 mg), aspartic acid (30.17 mg), and alanine (29.72 mg), as the major amino acids. free amino acids were 220.86 mg which were composed of essential amino acids (36.21 mg) inclusive of isoleucine (21.57 mg) and threonine (11.20 mg) and non-essential amino acids (184.65 mg) including glutamic acid (42.78 mg) and aspartic acid (32.44 mg) as major amino acids. Total content of amino acid derivatives was 187.85 me and that of hydroxyproline was highest as 121.50 mg.

• Journal of Astronomy and Space Sciences
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• v.22 no.4
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• pp.431-440
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• 2005

Local K-index is an indicator representing local geomagnetic activity in every 3 hour. For estimation of the local K-index, a reasonable determination of solar quiet curve (undisturbed daily variation of geomagnetic field) is quiet essential. To derive the solar quiet curve, the FMI method, which is one of representative algorithms, uses horizontal components (H and D) of 3 days magnetometer data from the previous day to the next day for a specific day. However, this method is not applicable to real time forecast since it always requires the next day data. In this study, we have devised a new method to estimate local K-index in near real-time by modifying the FMI method. The new method selects a recent quiet day whose $K_p$ indices, reported by NOAA/SEC are all lower than 3, and replace the previous day and the next day data by the recent quiet day data. We estimated 2,672 local K indices from Gyeongzu magnetometer in 2003, and then compared the indices with those from the conventional FMI method. We also compared the K indices with those from Kakioka observatory. As a result, we found that (1) K indices from the new method are nearly consistent with those of the conventional FMI method with a very high correlation (R=0.96); (2) onr local K indices also have a relatively high correlation (R=0.81) with those from Kakioka station. Our results show that the new method can be used for near real-time estimation of local K indices from Gyeongzu magnetometer.