• The Korean Journal of Food And Nutrition
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• v.37 no.2
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• pp.67-79
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• 2024

Yuzu (Citrus junos) undergoes traditional processing to create preserved yuzu with a sugar content of 50%. This study aimed to produce low-sugar yuzu syrup using artificial or natural sweeteners instead of sugar. Among artificial sweeteners, maltitol showed minimal browning and lack of deposition at high temperatures. The addition of xanthan gum (0.2%) and carboxymethyl cellulose (0.2%) resolved the issue of layer separation and viscosity decrease of yuzu syrup. Alternatively, grain syrup, a natural sweetener, improved viscosity and homogeneity without the additives. Yuzu syrups were developed using yuzu juice and preserved yuzu, with maltitol (20~40%) or grain syrup (50~70%) as the sweetener. Yuzu syrups containing 35% maltitol (M35) or 55% grain syrup (G55) had less than 5% and 10% free sugar, respectively. These syrups exhibited taste patterns similar to commercial yuzu syrup in analysis using an electronic tongue. Furthermore, M35 and G55 contained yuzu flavonoids at concentrations of 19.82 mg/g and 24.09 mg/g, respectively. Antioxidant activity (DPPH, ABTS radical scavenging) of M35 and G55 was equivalent to 10.55, 17.59 mg/100 g of Vitamin C and 97.39, 33.92 mg/100 g of Vitamin C, respectively. Consequently, M35 and G55 offer promising alternatives to preserved yuzu, providing low-sugar yuzu syrups enriched with functional ingredients.

• The Korean Journal of Food And Nutrition
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• v.37 no.3
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• pp.129-138
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• 2024

In this study, in order to develop an foaming tablet product using yuzu powder, yuzu powder was manufactured using different drying methods such as freeze-drying, 60℃ drying, and 40℃ drying, and then quality characteristics and functionality were analyzed. The naringin content per g of yuzu powder was 8.9 mg for freeze-drying and 8.8 mg for 60℃ drying, and the hesperidin content per g of yuzu powder was highest at 53.6 mg for freeze-drying and 46.2 mg for 60℃ drying. followed by 40℃drying (41.7 mg). The tyrosinase inhibitory activity of 60℃ dried powder was found to be twice as high as that of freeze dried powder. Accordingly, in order to develop an inner beauty product, foaming tablets were manufactured using hot air dried powder, and the quality characteristics and functional ingredients of the final foaming tablets were investigated. The foaming tablet prepared with yuzu powder content of 10 and 15% showed an inhibitory activity of tyrosinase of 73.7 %, which was 1.6 times higher than that of ascorbic acid (1 mM), which was a positive control, confirming its melanin production inhibition effect.

• The Korean Journal of Food And Nutrition
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• v.37 no.5
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• pp.236-243
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• 2024

The present study was conducted to investigate effects of rabbit meat extract on energy metabolism and muscle differentiation in C2C12 myotubes. Water extract of rabbit meat (10, 50, 100, and 200 ㎍/ml) was used to treat differentiated C2C12 cells. Reverse transcriptase polymerase chain reaction (RT-PCR) and western blot analysis were used to determine mRNA or protein levels of energy metabolism-related genes. Total adenosine triphosphate (ATP) content was also measured. Treatment with rabbit meat extract significantly increased expression levels of muscle differentiation markers (myogenin and myosin heavy chain) and mitochondrial biogenesis regulators (PGC1α, NRF1, and TFAM) in C2C12 myotubes compared to non-treated control. Additionally, rabbit meat extract activated phosphorylation of AMPK and acetyl-coA carboxylase (ACC). Rabbit meat extract significantly increased ATP contents in myotubes. These results suggest that rabbit meat extract has the potential to improve energy metabolism in skeletal muscles.

• Applied Biological Chemistry
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• v.17 no.1
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• pp.63-80
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• 1974

The chemical components of Citrus junos produced in Korea were divided into two parts; common and special components respectively. In the former the relation between the physiological effects of the plant and its ripening process was observed periodically while the latter was analyzed the ripening fruits for their effective utilization as food. The results are summarized as follows: 1. The analytical result of seasonal change showed that the rind ratio was higher than the flesh ratio and on a regional basis, the rind ratio was higher in the islands than on land areas. 2. In the experiment the moisture was increased until the third period, but afterwards it was made constant. While the content of crude fat, cellulose, ash, total acid and soluble non-nitrogen material were decreased until the third period and the cotent of cellulose and total acid were continuousely redused until the last period. In con trast with the above the content of reducing sugars was increased but the content of crude fat, cellulose, ash, crude protein and soluble non-nitrogen material were increased until last period. 3. The content of vitamin C was richer in the rind than in the flesh, in the Korean species than in the Japanese. 4. Free sugars; xylose, fructose, glucose were richer in the rind than in the flesh. 5. The content of volatile organic acids was richer in the rind than in the flesh. Among them, volatile acids, acetic acid, formic and n-valeric acid were found in the rind and formic acid, acetic acid and propionic acid were deteceed in the flesh. 6. The total content of non-volatile acids was richer in the flesh than in the rind. In the kind of non-volatile acids, citric acid,glutaric acid, malic acid, tartaric acid, oxalic acid, malonic acid, succinic acid and an unknown acid were found in the rind and citric acid, malic acid, succinic acid, oxalic acid, glutaric acid and malonic acid in the flesh. 7. Three kinds of aromatic components: D-limonene, ${\alpha}-pinene$, p-cymene and seven other kinds of unknown aromatic components were detected in neutral essential oils. Among them, D-limonene seemed to be main aromatic component in the fruits. 8. From the above results it is confirmed that both rind and flesh of the ripened fruit could be utilized for food effectively, and unripened fruits are suitable for producing citric acid, ripened fruits are also useful for producing juice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.945-951
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• 2002

To propose quality improvement for commercial sikhe, we assessed the opinion of Food and Nutrition specialists about the status of utilization, preference and quality of commercial sikhe. Questionaires were hand-delivered to 530 subjects consisted of University students and faculties of Department of Food and Nutrition at 8 cities (Seoul, Incheon and Gyeonggi, Daejon and Chungnam, Cheongju and Chungbuk, Daegu and Gyeongbuk, Jeonbuk, Gwangju and Jeonnam, Husan and Gyeongnam) in Korea and the complete data of 328 subjects were statistically analyzed using SPSS Program for Window (mean, $\chi$$^2$, t-test, Pearson's correlation coefficient). Questionaires were consisted of sociodemographics, frequency and occasion of purchasing, opinion of quality and improvement points and sen-sory characteristics. Occasion of purchasing commercial sikhe is in order of ordinary day> for present> special day. Most subjects answered that commercial sikhe was different from home-made one. The reasons not to per-chase were the most in no preference and the next, in seeming to be different taste from home-made one. Points for further improvement in commercial sikhe were in order of taste> amount and floating of rice >flavor. The correlation coefficients between over-all preference and sensory characteristics showed positively in taste (0.54), texture of rice (0.476), content of malt (0.398).

• Sijohaknonchong
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• v.21
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• pp.207-239
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• 2004

Jungchull(정철) was a very famous poet of Kasa(가사), Sijo(시조) and Hansi(한시) during the middle period of the Chosun kingdom. He has been studied by modern scholars mainly as a poet of Kasa(가사). These days, however, his Sijos are being studied as an important literary achievement. The purpose of this study is to analyze the pursuit of reality and elegance expressed in Jungchull's Sijo in order to understand his Sijos more deeply. In the process of this discussion, I will take a look at some of his Kasa(가사), Hansi(한시) and biography also, and I will compare his Sijo(시조) with that of his teacher's, friend's and senior's. Jungchull considered it important to become an official in the royal court because he was a Confucian scholar who believed in jugi-theory (주기론), in which all realistic phenomena is evaluated(Confucianism is very realistic in essence), and he had a happy life in the royal household until he was ten years old. I found that characteristics of his "realistic pursuit" are represented in his Sijo by two situations: the one is when he is apart from the King, and the other when he is together with the King. In all situations, though, he pursued an official position in the royal court. When he was apart from the king, his absolute resolution to follow the King was expressed in his not being able to sleep. In his sijo, he asks the wild duck to inform him of the King's welfare. He tries to flap his wings, to be the water or the moon in order to reach the royal household where the King was living. When he recognizes it's impossible, he expresses his perfect loyalty to the King in his Sijo by using literary paradox. According to this, he describes himself as not an able scholar, but also not a flattering scholar. In his sijo, he reminisces about working for the King in the royal household, when he had a good relationship with the King. But when he was an official in the province in a good relationship with the King, he expressed his intention of coming back to the royal household in order to be with the King again. From this we can ascertain that his pursuit of reality means to occupy an official position in the royal household, to serve the King and to have political power among of the officials. His elegance, expressed in his sijo, is deeply related to his absolute political pursuit of the King. He describes two kinds of elegance: nature related elegance and drinking alcohol related elegance. Two kinds of nature related elegance were delineated in his sijo, depending upon his political situation. When he had a good relationship with the King, occupying an official position, he delineated his gladness and free-heart in harmonizing with nature. But when he lost his official position. he expressed his purity using nature, and exclusion from nature. These kinds of nature related elegance were different from that of the usual Confucian scholar, for example, contemporaries Lee Hwang Next, two kinds of drinking alcohol related elegance were delineated in his sijo depending upon his political situation. More often he depicted excitement and composure of mind in his sijo by drinking alcohol in good situations than in efforts to overcome his agony in bad situations. The tradition of overcoming one's agony by drinking alcohol in bad situation was discovered by this writer in Jungchull's teacher's, and also his junior's sijo. Lastly in my next research paper future, I will look at the reason why certain various themes are represented in Jungchull's sijo, and what their the relationships are, to understand his literary works as a whole.

• Applied Biological Chemistry
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• v.9
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• pp.97-104
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• 1968

A survey of the free amino acids and free sugars in the juice of fourteen citrus varieties was made by means of paper chromatography and the pectin content in the rind was detected The results of the survey are summarized as follows. 1) Sixteen aminoacids detecteu in fourteen varieties under the condition of this study were distributed with. different frequency as follow. Proline, gamma-amino-butyric acid, alanine, valine, serine, glutamic acid, aspartic acid (in 14 varieties), lysine(12), leucine threonine(11), isoleucine(10), arginine(9), glycine(6) ${\beta}-alanine$(4) asparagine(3) unknown(2). 2) Proline, gamma-amino-butyric acid were mostly abundant in all varieties and alanine was next in the amount. 3) The varieties in the decreasing order of number of amino acids container were C. grandis madow C. leiocarpa (14 acids), C. sulcata, C. hassaku. native citron, Fortunella japonica(13) C. grandis heiko, C. Tamurana iyo, C. nobilis(12) C. reticulata C. junos(11) C. natsudaidai(10) C. miyakawa unshiu, C. ohali unshiu(9). 4) The varieties which appear to contain all essential amino acids(6 acids)detected were C. grandis madow C. grandis heiko, C. sulcata, C. Tamurana iyo, C. hassaku and native citron, and C. natsudaidai, C. unshiu were the least (1-3 acids). 5) Glucose fructose, sucrose and maltose were detected in all varieties. 6) The pectin content in the rind ranged from 8.64% F.W.(C. junos) up to 17.0% for C, grandis madow and the mean was $11.63{\pm}2.69%$.

• Korean Journal of Biological Psychiatry
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• v.15 no.2
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• pp.83-91
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• 2008

Objectives : Neurological soft signs have been regarded as endophenotypes associated with the genetic basis of schizophrenia. This study was to investigate the intra-familial correlations of the neurological soft signs according to their genetic loading. Methods : Schizophrenic patients(N=14) were included, who had one parent with a family history of schizophrenia and the other without it. Genetic loading was determined by the patient's family history of schizophrenia using the Family Interview for Genetic Studies(FIGS). These parents were subdivided into two groups. The first group was designated as 'presumed carriers'(N=9) of genetic loading, who had one or more schizophreic firstor second-degree relatives. The second group was designated as 'presumed non-carriers'(N=11) of genetic loading, who had no schizophrenic first- or second-degree relatives. Normal controls(N=12) consisted of people without schizophrenic relatives. NSS were evaluated using the Neurological Evaluation Scale-Korean Version (NES-K), and the intra-familial correlations of NSS were tested using the Intra-Class Coefficients(ICC) method. Results : The scores of Motor Coordination subdimension of NES-K were significantly correlated between the patients and their presumed carriers(ICC=.804, p=.016), but not significantly correlated between the patients and their presumed noncarriers. In other subdimensions of NES-K, no significant correlation were found between the patients and their parents regardless of the genetic loading. But, there were no statistically significant differences in the scores of Motor Coordination subdimension of NES-K between the patients and controls. Conclusion : This study did not prove that the neurological soft signs might be an endophenotype of schizophrenia that cosegregate with the genetic loading. The future study using more subjects than this would be needed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.4
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• pp.535-544
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• 2015

Yield per recruit model is the most popular method for fisheries stock assessment. However, stock assessment using yield per recruit model can lead to recruitment overfishing as this model only considers the maximum yield per recruit without spawning biomass for reproduction. For this reason, spawning biomass per recruit model which reveals variations of spawning stock biomass per fishing mortality (F) and age at first capture ($t_c$) is considered as more proper method for stock assessment. There are mainly two methods for spawning biomass per recruit model known as age specific selectivity method and knife-edged selectivity method. In the knife-edged selectivity method, the spawning biomass per recruit has been often calculated using biomass per recruit value by multiplying the maturity ratio of the recruited age. But the maturity ratio in the previous method was not considered properly in previous studies. Therefore, a new method of the knife-edged selectivity model was suggested in this study using a weighted average of the maturity ratio for ages from the first capture to the lifespan. The optimum fishing mortality in terms of $F_{35%}$ which was obtained from the new method was compared to the old method for small yellow croaker stock in Korea. The value of $F_{35%}$ using the new knife-edged selectivity model was 0.302/year and the value using the old model was 0.349/year. However, the value of $F_{35%}$ using the age specific selectivity model was estimated as 0.320/year which was closer to the value from the new knife-edged selectivity model.

• Journal of Nutrition and Health
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• v.47 no.4
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• pp.221-228
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• 2014

Purpose: Citron seed oil (CSO) has been reported to have high antioxidant activity. However, the composition and other biologically activities of CSO have not been reported. In this study, we confirmed the fatty acid composition of CSO, which may be beneficial to vascular disease and obesity. Methods: We investigated the oil composition of CSO using gas chromatography coupled with mass spectrometry (GC-MS) analysis, and cytotoxicity was confirmed by Cell Counting Kit-8 (CCK-8) assay. Nitric oxide (NO) production in human umbilical vein endothelial cells (HUVECs) was measured using Griess reagent, and lipid accumulation and leptin secretion in 3T3-L1 cells were measured by Oil-Red O staining and commercial ELISA kit, respectively. Results: GC-MS analysis indicated that CSO contains several components, including linoleic acid, oleic acid, palmitic acid, stearic acid, linolenic acid, palmitoleic acid, and arachidic acid. In physiological activity analysis, CSO did not induce cytotoxic effects in HUVECs and 3T3-L1 cells. Further, CSO significantly induced nitric oxide and leptin secretion as well as inhibited lipid accumulation. Conclusion: CSO increased NO release, inhibited lipid accumulation, and induced leptin secretion, suggesting it may be useful for the management of vessels and weight gain. Although further studies are required to investigate the safety and mechanism of action of CSO, our results show that the composition and physiological activity of CSO are sufficient for its use as functional edible oil.