• Journal of Food Hygiene and Safety
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• v.32 no.2
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• pp.83-88
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• 2017

We introduced disposable amperometric immunosensors for the detection of Sildenafil and Vardenafil (SDF/VDF) based on screen printed carbon electrodes. The developed immunosensors were used as a non-competitive sandwich-type enzyme immunoassay with a horseradish peroxidase label. The sensors were constructed on screen printed carbon electrodes by the simple electrochemical deposition of a reduced graphene oxide and chitosan (ErGO-CS) composite. To evaluate the sensing chemistry and optimize the sensor characteristics, a series of electrochemical experiments were carried out including electrochemical impedance spectroscopy, cyclic voltammetry and amperometry. The sensors showed a linear response to SDF/VDF concentrations in a range from 100 pg/mL to 300 ng/mL. The lower detection limit was calculated to be 55 pg/mL, the sensitivity was calculated to be $1.02{\mu}Ang/mL/cm^2$, and the sensor performance exhibited good reproducibility with a relative standard deviation (RSD) of 7.1%. The proposed sensing chemistry strategy and the sensor format can be used as a simple, cost-effective, and feasible method for the in-field analysis of SDF/VDF in functional or health supplement food samples.

• Journal of Nutrition and Health
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• v.42 no.4
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• pp.397-405
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• 2009

A trienzyme extraction method (use of ${\alpha}$-amylase, protease and folate conjugase) for food folate assay has been used to release folate from the food matrix. In order to reduce the incubation time with three enzymes, folate values were compared between two incubation protocols; separate incubation (SI, incubated with ${\alpha}$-amylase and conjugase separately for 2 hours after protease treatment) and combined incubation (CI, incubated with ${\alpha}$-amylase and conjugase together for 2 hours after protease treatment) using 88 food items from 12 kinds of fast foods and processed foods. We found that folate values by CI were comparable to or higher than those by SI, indicating that CI might be a better extraction procedure to shorten the entire incubation time. We measured folate contents in 49 fast foods and 26 processed foods by microbiological assay after CI. Mean folate contents of one serving of various burgers ranged from 43.1 to 62.0 ${\mu}g$. One serving of French fries, pizza, sandwich and triangled kimbab contained a mean of 53.3, 28.4, 47.4, and 25.7 ${\mu}g$ of folate, respectively. Folate contents of non-alcoholic beverages were very low, ranging from 1.0 to 5.2 ${\mu}g$/100 g. Some of our values were comparable to the values in the folate database published in Korean Nutrition Society, however, some of the published values were 140 times higher than the measured values in this study. Folate values measured by the more recent modifications here can be used to update Korean folate database to accurately estimate dietary folate intake.

• Journal of Community Nutrition
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• v.6 no.2
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• pp.103-109
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• 2004

Body antioxidant status is an important factor for the prevention of many chronic diseases in the elderly. This study was done to investigate antioxidant status and its relationship to immune response by measuring plasma cytokine (IL-2 and IL-6) levels in elderly women. Subjects were 76 elderly women aged over 60 years, visiting Jangwhi Social Welfare Center of Seongbook-Gu in Seoul. Subjects were divided into 3 groups according to age (< 65, 65 - 74, > 75). Dietary intakes were assessed by semi-quantitative food frequency questionnaires (SFFQ). Plasma vitamin C level was measured by 2,4-dinitrophenylhydrazine method and plasma levels of vitamin E, A and ${\beta}$-carotene were measured by HPLC. Plasma levels of IL-2 and IL-6 were determined with a solid phase sandwich enzyme linked-immuno-sorbent assay (ELISA) using commercial kits. The average intakes of antioxidant vitamins were 96.3mg (137.5% of RDA) for vitamin C and 523.3 ${\mu}$gRE (74.8% of RDA) for vitamin A in elderly women. All of the average plasma levels of antioxidant vitamins were within normal range. However the percentage of the elderly women with deficiency plus marginal values were 7.9% in vitamin C, 9.2% in vitamin A and 7.9% in vitamin E. Plasma levels of IL-2 and IL-6 were 27.1${\pm}$7.1pg/ml and 5.9${\pm}$5.3pg/ml in elderly women. Correlation data showed that plasma IL-2 level was negatively correlated with plasma vitamin C level. In addition, IL-6 level was also negatively correlated with plasma vitamin C, A and E levels, respectively. There was a significant positive correlation between erythrocyte thiobarbituric acid-reactive substance(TB-ARS) level and plasma IL-2 or IL-6 levels. In addition, erythrocyte TBARS level showed a significant positive correlation with plasma total antioxidant status (TAS) level and a significant negative correlation with plasma vitamin C level. Overall results might imply that the decreased levels of antioxidant vitamins result in an increase in oxidative stress and thereby increase cytokine production such as IL-2 and IL-6. However further research is required to elucidate these relationships.

• Research in Plant Disease
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• v.30 no.2
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• pp.157-164
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• 2024

Jack bean (Canavalia ensiformis) is one of healthy products for fermented or functional food in Korea and is widely distributed and cultivated worldwide. During August 2022, Jack bean plants showing symptoms of yellow flecks, chlorosis, necrotic spots and mosaic were observed in Jangheung-gun, South Korea. By transmission electron microscopy, flexuous filamentous virus particles of approximately 750×13 nm in size were observed in the symptomatic leaf samples. The infection of a Korean isolate of clover yellow vein virus (ClYVV-Ce-JH) was confirmed using double antibody sandwich enzyme-linked sorbent assay, reverse transcription polymerase chain reaction and high-throughput sequencing. The complete genome sequence of ClYVV-Ce-JH consists of 9,549 nucleotides (nt) excluding the poly (A) tail and encodes 3,072 amino acids (aa), with an AUG start and UAG stop codon, containing one open reading frame that is typical of a potyvirus polyprotein. The polyprotein of ClYVV-Ce-JH was divided into ten proteins and each protein's cleavage sites were determined. The coat protein (CP) and polyprotein of ClYVV-Ce-JH were compared at the nt and aa levels with those of the previously reported 14 ClYVV isolates. ClYVV-Ce-JH shared 92.62% to 99.63% and 93.39% to 98.05% at the CP and polyprotein homology. To our knowledge, this is the first report of a Korean isolate of ClYVV from Jack bean plants and the complete genome sequence of a ClYVV Jack bean isolate in the world.

• Food Science of Animal Resources
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• v.24 no.2
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• pp.171-175
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• 2004

Insulin-like growth factor-I (IGF-I) rich fraction, which was obtained molecules ranged between 30 kDa and 1 kDa, was fractionated by ultrafiltration from bovine colostral whey with 30 kDa and 1 kDa membrane. IGF-I included in fractionated IGF-I rich fraction was confirmed by SDS-PAGE and western blotting and then the quantity of IGF-I was measured by ELISA. IGF-I concentration in IGF-I rich fraction was 10ng/mg protein. Effect of IGF-I rich fraction on in vitro proliferation of several cells was tested. IEC-6 cell proliferation rate was increased 60％. 53％, 30％, and 20％ at l0ng, 1ng, 0.1ng and IGF-I of IGF-I, respectively, compared to control group which was not supplemented by IGF-I rich fraction. IGF-I rich fraction stimulated in vitro proliferation of IEC-6 cell in a dose dependent manner by increasing cell number. Detroit 551 cell proliferation was enhanced 56％ and 26％ at 10ng and 1ng level of IGF-I, respectively, compared to control group. EL-4 cell and L6 cell proliferation was increased 53％ and 46％ at 10ng of IGF-I, respectively, compared to control group.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.3 no.2
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• pp.175-180
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• 2000

Purpose: Leptin is an adipocyte-derived blood-borne satiety factor that acts on its cognate leptin receptor in the hypothalamus, thereby regulating food intake and energy expenditure. We measured the leptin concentrations in serum of normal and obese children with human leptin ELISA kit, unlike previous study with leptin RIA kit and investigated the relationship between leptin concentrations and body mass index, gender, and age. Methods: We measured serum concentrations of leptin in 67 children who were visited to the Department of Pediatrics, Chungnam National University Hospital during the period of 5 months from February, 1999 to June, 1999. Height, weight, obesity index, and body mass index were measured in 67 subjects. Leptin values in serum were measured by sandwich ELISA method. Data analysis was done according to the obesity, body mass index, gender and age. Results: The mean concentration of leptin was $7.69{\pm}8.83\;ng/ml$ in normal children group and $36.34{\pm}18.57\;ng/ml$ in obese group. Serum leptin concentrations were significant correlation with the body mass index (p<0.01). Serum leptin concentration was significant higher in the group of over 10 years of age (p<0.01). Leptin levels showed no significant difference by gender. Conclusion: Serum leptin levels were significantly higher in obesity group than in control one, and they were correlated with body mass index and age. Measurements of leptin value by sandwich ELISA method are very useful and easily applicable to determine obesity.

• BMB Reports
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• v.40 no.4
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• pp.459-466
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• 2007

The cDNA sequence of the Japanese flounder (Paralychthys olivaceus) IgD has been previously reported (GenBank accession no. AB052658) and this was followed by the detection of IgD mRNA expression in some flounder organ tissues. However, it has not been determined whether the flounder IgD gene is virtually expressed into IgD protein. To characterize the flounder immunoglobulins utilized in elucidating the mechanism, evolution and diversity of the flounder immune system, antibodies specific to IgD and IgM were necessary. In the present study, partial flounder recombinant IgD (rIgD), IgM (rIgM) and the conserved regions of IgD and IgM (rCIg) were produced by cloning the cDNA sequence using isotype specific primers which were designed to produce unique fragments of IgD and IgM specific amino acid sequences. The production of recombinant Igs was ascertained by SDS-gel electrophoresis and immunoblot analysis using anti-T7$\cdot}$Taq antibody. The produced recombinant Igs were purified using affinity columns, and used as immunogens. Antibodies specific to the isotype of flounder Igs were generated by immunizing rabbits with rfIgs and the antibodies produced were identified by enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Specificities of the generated antibodies were evaluated by testing cross-reactivity between recombinant IgM and IgD. By ELISA, rabbit antibodies against the rfIgD fragment (anti-rfIgD) failed to recognize any kind of flounder serum Igs, whereas respective antibodies against rfCIg (anti-rfCIg) and rfIgM fragments (anti-rfIgM) reacted with serum Igs. Likewise, in immunoblot assays, though anti-rfIgD did not, both anti-rfCIg and anti-rfIgM bound with the ~85 kd flounder IgM heavy chain. By flow cytometry analysis, anti-rfCIg, anti-rfIgD and anti-rfIgM reacted with 6%, 3% and 6.5% of cells, respectively, suggesting that flounder IgD is not secreted in serum but expressed on flounder B-like cell surfaces as in mammals. Antibodies produced against recombinant flounder Igs could be used to develop sandwich assay systems for detecting flounder Igs and for further investigating the flounder immune system.

• Culinary science and hospitality research
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• v.22 no.5
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• pp.313-324
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• 2016

The purpose of this study was to investigate in the Age-Specific Choice Attributes of Bakery Product Purchasers on Gyeongbuk. The results were as follows : The findings of survey showed that in general characteristics of respondents, the number of males was 194(33.4%) and females 387(66.6%), so the number of females was slightly higher than that of males. On the matter of bakery purchase attributes, in the case of food life by ages, the 20s belonged to more 'taste-interest type'(44.7%) and the 30s~50s were more 'health-interest type'(p<0.001). When purchasing bakery products, consumers had different importance factors such as taste 61.8%, nutrition 17.6%, price 9.1%. In terms of taste, by ages the 20s were 73.9%, the 30s 65.8%, the 40s 55.8% and the 50s 46.0%(p<0.001). In bakery-using type, franchise bakery was 70.4%, window bakery 16.0%, in the case of franchise bakery by ages, the 20s were 70.2%, the 30s 78.1%, the 40s 72.1% and the 50s 56.0%(p<0.001). In their preference of bakery products, various kinds of sandwich the 20s liked by 37.3%, the 50s by 12.0%(p<0.001). Natural fermented bread accounted for 14.9% in the 20s and 37.0% in the 50s(p<0.001).

• Journal of the East Asian Society of Dietary Life
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• v.12 no.2
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• pp.79-90
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• 2002

This study was performed to investigate the recognition and the preference of pickles by using the questionnaire. The subjects of this study consisted of 217 males and 359 females in the Kyongbuk area. The results were summarized as follows: Among the respondents 94.8% have hon pickles and mostly have eaten garnished pickle with pizza. The chief element to be considered in selecting the commercial pickle was considered to be 'sanitation'. and 'good taste'. The most important factor on preparation and production of pickle showed a receiving high mean value of 4.77. On their perception of pickle, 'pickle stimulate their appetite'received highest scare of 3.97. More than 41% of the respondents liked pickles and favorite pickle seasoning was vinegar(77.2%). Among the respondents 49.7% and 17.2% suggested the development fruit pickle and mushroom pickle respectively. Of the famished dishes with a pickle, preferable food was pizza, hamburg sandwich, pork cutlet, salad and hamburg steak in the order.