• Food Science and Preservation
• /
• v.24 no.7
• /
• pp.983-991
• /
• 2017

This study was performed to update the National Standard Food Composition Table (NSFCT) published by Korea Rural Development Administration, especially focusing on vitamin $B_{12}$ for Korean pork. Total 7 primal and 22 retail fresh cuts of Korean pork were analyzed for vitamin $B_{12}$ and the applied immunoaffinity-HPLC was validated. Vitamin $B_{12}$ assay by immunoaffinity-HPLC obtained recoveries over 95% and coefficient variations of precision below about 10%, which met the limits required for validation acceptance. Limits of detection and quantification of immunoaffinity-HPLC were 0.01 and $0.33{\mu}g/100g$, respectively. Quality control chart showed that analysis performance was excellent during the entire of study. Vitamin $B_{12}$ contents of pork cuts significantly varied depending the types of primal and its retail cuts (p<0.05). Belly, Boston butt, rib cuts showed relatively high vitamin $B_{12}$ contents compared to other primal cuts. Vitamin $B_{12}$ content of pork retail cuts were also significantly different within the same primal cuts (p<0.05). Among 22 retail cuts, the highest vitamin $B_{12}$ was observed in Tosisal in belly primal part ($0.98{\mu}g/100g$) while both Aldeungsimsal in loin and Hongdukkaesal in hide leg were the lowest by $0.33{\mu}g/100g$. This study provides reliable vitamin $B_{12}$ data for the Korean pork fresh cuts through standard sampling, method validation and analytical quality control, which would be used for update of Korean NSFCT.

• Korean Journal of Plant Resources
• /
• v.31 no.2
• /
• pp.124-135
• /
• 2018

The study was performed to explore the molecular changes in the vegetative stage (3-and 5-leaf) of sorghum under waterlogging stress. A total of 74 differentially expressed protein spots were analyzed using LTQ-FT-ICR MS. Among them, 12 proteins were up-regulated and 3 proteins were down-regulated. Mass spectrometry (MS) results showed that about 50% of the proteins involved in various metabolic processes. The level of protein expression of malate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase related to carbohydrate metabolic process increased in both 3 and 5-leaf stage under waterlogging stress. These proteins are known to function as antistress agents against waterlogging stress. The expression of oxygen-evolving enhancer protein 1 protein related to photosynthesis was slightly increased in the treated group than in the control group, however the expression level was increased in the 5-leaf stage compared to the 3-leaf stage. Probable phospholipid hydroperoxide glutathione peroxidase protein and superoxide dismutase protein related to response to oxidative stress showed the highest expression level in 5-leaf stage treatment. This suggests that the production of reactive oxygen species by the waterlogging stress was the most abundant in the 5-leaf treatment group, and the expression of the antioxidant defense protein was increased.

• Korean Journal of Microbiology
• /
• v.52 no.1
• /
• pp.10-17
• /
• 2016

Enzyme immunoassay to analyze specific binding activity of antibody to antigen uses horseradish peroxidase (HRP) or alkaline phosphatase (AP). Chemical methods are usually used for coupling of these enzymes to antibody, which is complicated and random cross-linking process. As results, it causes decreases or loss of functional activity of either antibody or enzyme. In addition, most enzyme assays use secondary antibody to detect antigen binding activity of primary antibody. Enzymes coupled to secondary antibody provide a binding signal by substrate-based color development, suggesting secondary antibody is required in enzyme immunoassay. Additional incubation time for binding of secondary antibody should also be necessary. More importantly, non-specific binding activity caused by secondary antibody should also be eliminated. In this study, we cloned AP isolated from Escherichia coli (E. coli) chromosome by PCR and fused to) hAY4 single-chain variable domain fragment (ScFv) specific to death receptor (DR4) which is a receptor for tumor necrosis factor ${\alpha}$ related apoptosis induced ligand (TRAIL). hAY4 ScFv-AP expressed in E. coli showed 73.8 kDa as a monomer in SDS-PAGE. However, this fusion protein shown in size-exclusion chromatography (SEC) exhibited 147.6 kDa as a dimer confirming that natural dimerization of AP by non-covalent association induced ScFv-AP dimerization. In several immunoassay such as ELISA, Western blot and immunocytochemistry, it showed antigen binding activity by color development of substrates catalyzed by AP directly fused to primary hAY4 ScFv without secondary antibody. In summary, hAY4 ScFv-AP fusion protein was successfully purified as a soluble dimeric form in E. coli and showed antigen binding activity in several immunoassays without addition of secondary antibody which sometimes causes time-consuming, expensive and non-specific false binding.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.8
• /
• pp.1217-1227
• /
• 2014

This study investigated the physicochemical properties and antioxidant activity of vinegar added with different levels (0%, 1%, 3%, 5%, and 7%) of Akebia quinata fruit during two-step fermentation. The physicochemical properties of vinegar evaluated were pH, total acidity, alcohol, and total sugar and amino acid contents. The antioxidant activities were based on ABTS radical scavenging activity, SOD-like activity, and reducing power. During alcohol fermentation, total acidity and alcohol contents of vinegar increased, but total sugar contents decreased. During acid fermentation, total acidities of vinegar increased. Vinegar added with 7% A. quinata fruit showed the highest total sensory score. Total polyphenol contents of vinegar added with 0% and 1% A. quinata fruit were not significantly different. However, vinegar added with 3, 5, and 7% A. quinata fruit showed significantly higher total polyphenol contents of 136.6, 381.59, and 415.35 mg/100 g, respectively, after 13 days of fermentation. Further, total flavonoid contents of vinegar added with 0~7% A. quinata fruit significantly increased to 21.73, 15.79, 15.15, 26.19, and 26.87 mg/100 g, respectively, after 13 days of fermentation. In addition, tannin contents of vinegar added with 0~7% A. quinata fruit significantly increased to 0.2042, 0.2004, 0.1255, 0.1384, and 0.1255 mg/100 g, respectively, after 13 days of fermentation. Moreover, ABTS radical scavenging activities of vinegar added with 0~7% A. quinata fruit significantly increased to 5.87, 12.59, 25.63, 34.02, and 35.25, respectively, after 13 days of fermentation at a concentration of 5 mg/mL. Additionally, SOD-like activities of vinegar added with 0~7% A. quinata fruit significantly increased to 8.22, 17.49, 16.86, 16.89, and 15.68%, respectively, after 13 days of fermentation. Reducing power of 7% A. quinata fruit was 0.527 after 1 day and 1.539 at the end of fermentation. Our results demonstrate that antioxidant activity significantly increased during fermentation according to the content of A. quinata. Further, the total polyphenol, flavonoid, and tannin contents were shown to be closely related with antioxidant activities. Thus, A. quinata could be effectively used as a vinegar and functional food material based on its antioxidant activity.

• Clinical and Experimental Reproductive Medicine
• /
• v.26 no.3
• /
• pp.407-417
• /
• 1999

Objective: Mammalian follicle cells are the most important somatic cells which help oocytes grow, mature and ovulate and thus are believed to provide oocytes with various functional and structural components. In the present study we have examined whether cumulus or granulosa cells might playa role in establishing the plasma membrane structure of mouse oocytes during meiotic maturation. Design: In particular the differential resistances of mouse oocytes against chymotrypsin treatment were examined following culture with or without cumulus or granulosa cells, or in these cell-conditioned media. Results: When mouse denuded oocytes, freed from their surrounding cumulus cells, were cultured in vitro for $17{\sim}18hr$ and then treated with 1% chymotrypsin, half of the oocytes underwent degeneration within 37.5 min ($t_{50}=37.5{\pm}7.5min$) after the treatment. In contrast cumulus-enclosed oocytes showed $t_{50}=207.0$. Similarly, when oocytes were co-cultured with cumulus cells which were not associated with the oocytes but present in the same medium, the $t_{50}$ of co-cultured oocytes was $177.5{\pm}13.1min$. Furthermore, when oocytes were cultured in the cumulus cell-conditioned medium, $t_{50}$ of these oocytes was $190.0{\pm}10.8min$ whereas $t_{50}$ of the oocytes cultured in M16 alone was $25.5{\pm}2.9min$. Granulosa cell-conditioned medium also increased the resistance of oocytes against chymotrypsin treatment such that $t_{50}$ of oocytes cultured in granulosa cell-conditioned medium was $152.5{\pm}19.0min$ while that of oocytes cultured in M16 alone was $70.0{\pm}8.2min$. To see what molecular components of follicle cell-conditioned medium are involved in the above effects, the granulosa cell-conditioned medium was separated into two fractions by using Microcon-10 membrane filter having a 10 kDa cut-off range. When denuded oocytes were cultured in medium containing the retentate, $t_{50}$ of the oocytes was $70.0{\pm}10.5min$. In contrast, $t_{50}$ of the denuded oocytes cultured in medium containing the filtrate was $142.0{\pm}26.5min$. $T_{50}$ of denuded oocytes cultured in medium containing both retentate and filtrate was $188.0{\pm}13.6min$. However, $t_{50}$ of denuded oocytes cultured in M16 alone was $70.0{\pm}11.0min$ and that of oocytes cultured in whole granulosa cell-conditioned medium was $156.0{\pm}27.9min$. When surface membrane proteins of oocytes were electrophoretically analyzed, no difference was found between the protein profiles of oocytes cultured in M16 alone and of those cultured in the filtrate. Conclusions: Based upon these results, it is concluded that mouse follicle cells secrete a factor(s) which enhance the resistance of mouse oocytes against a proteolytic enzyme treatment. The factor appears to be a small molecules having a molecular weight less than 10 kDa.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.64 no.2
• /
• pp.109-126
• /
• 2019

Genetic resources of 84 species of Setaria italica BEAUVOIS, Sorghum bicolor, and Panicum miliaceum were collected to select the adaptable miscellaneous cereals in Saemangeum reclaimed land. The adaptability of Sorghum bicolor in reclaimed land was the highest among the three cereals cultivated on reclaimed land. The ratio of the average height of Sorghum bicolor plants cultivated in reclaimed land/normal field was 0.82, that of Panicum miliaceum was 0.61, and that of Setaria italica BEAUVOIS was 0.51. Three species of Sorghum bicolor, Satangdajuk, Kkamansusu, and Nampungcharl, were selected as potential genetic resources as they had excellent adaptability to reclaimed land. The yield of Satandaejuk on reclaimed land was 229.4 kg/10a, and the yield ratio of reclaimed land/normal field was 89.3%. The yield of Kkamansusu was 227.4 kg/10a, with reclaimed land/normal field ratio of 87.8%, and yield of Nampungcharl was 239.6 kg/10a, and reclaimed land/normal field ratio of 86%. In order to study the salt tolerance of selected genetic resources, we conducted salinity test. Salinity tolerance of Sorghum bicolor species-Satangdajuk, Kkamansusu, Nampungcharl was excellent compared to that of the other cereals. Among these, Satandaejuk had to highest salt tolerance level. Polyphenols, flavonoids, and detoxification of free radical were also studied. The anti-diabetic property of the cereals was also analyzed by ${\alpha}$-glucosidase inhibitory activity. We confirmed that the functionality of 3 lines in reclaimed land had improved in all the functional analysis categories when compared to that with yield in the normal field. Polyphenol, an antioxidant, increased in the range of 2~26% when cultivated in reclaimed land and the flavonoid content also increased from 8.5 to 55.6%. DPPH elimination capability, the ability to scavenge harmful reactive oxygen, also increased from 16.7 to 47% when cultivated in reclaimed land. The anti-diabetic activity and ${\alpha}$-glucosidase inhibition activity of selected Sorghum bicolor species-Satangdajuk, Kkamansusu, Nampungcharl also increased from 18.4 to 19.9% when cultivated on reclaimed land.

• Journal of Life Science
• /
• v.28 no.12
• /
• pp.1416-1423
• /
• 2018

With strong biotin binding affinity ($K_D=10^{-14}M$), the tetrameric feature of streptavidin could be used to increase the antigen binding activity of a camel heavy chain (VHH) antibody through their fusion, here stained with biotinylated horseradish peroxidase and subsequent immunoassays ELISA and Western blot analysis. For this application, we cloned the streptavidin gene amplified from the Streptomyces avidinii chromosome by PCR, and this was fused to the gene of the 8B9 VHH antibody which is specific to green fluorescent protein (GFP) antigens. To express a soluble fusion protein in Escherichia coli, we used the pUC119 plasmid-based expression system which uses the lacZ promoter for induction by IPTG, the pelB leader sequence at the N-terminus for secretion into the periplasmic space, and six polyhistidine tags at the C-terminus for purification of the expressed proteins using an $Ni^+$-NTA-agarose column. Although streptavidin is toxic to E. coli because of its strong biotin binding property, this soluble fusion protein was expressed successfully. In SDS-PAGE, the size of the purified fusion protein was 122.4 kDa in its native condition and 30.6 kDa once denatured by boiling, suggesting the tetramerization of the monomeric subunit by non-covalent association through the streptavidin moiety fusing to the 8B9 VHH antibody. In addition, this fusion protein showed biotin binding activity similar to streptavidin as well as GFP antigen binding activity through both ELISA and Western blot analysis. In conclusion, the protein resulting from the fusion of an 8B9 VHH antibody with streptavidin was successfully expressed and purified as a soluble tetramer in E. coli; it showed both biotin and GFP antigen binding activity suggesting the possible production of a tetrameric and bifunctional VHH antibody.

• Journal of Korean Society of Forest Science
• /
• v.100 no.3
• /
• pp.408-416
• /
• 2011

Leaf and bulb of wild garlic (Allium victorials var. platyphyllum) from Ulleung Island and Gangneung region were extracted with water and 70% ethanol and investigated on its antioxidative activity. Total polyphenol content of Ulleung island wild garlic was higher than that of Gangneung region. Total polyphenol content in bulb was high compared to content of the leaves, and 70% ethanol extract of Ulleung Island leaf was high in 72.50 mg/g. Flavonoid content in leaf was higher than that of bulb, 70% ethanol extract of Ulleung Island leaf was high in 73.30 mg/g. Electron donating activity of 70% ethanol extract from Ulleung island and water extracts (55.13%) from Gangneung were higher than those of other extracts. Bulb extracts on electron donating activity were higher than those of the leaf extracts. SOD like activity of extracts was high in 70% ethanol extract of wild gallic leaf cultivated at Gangneung. Hydroxy radical scavenging activity of wild gallic was high in leaf extracts compared to activity of bulb extracts. Hydroxy radical scavenging activity (58.85%) of Ulleung island wild gallic leaf extracts was higher than that of the wild gallic leaves of Gangneung. Lipid peroxidation inhibitory activity was both high in water and 70% ethanol leaf extracts of Ulleung island and Gangneung region, especially, 70% ethanol extract of leaves from Ulleung island was the highest 73.33%. These results suggest that extracts from wild garlic could be used as an antioxidative functional food source.

• Journal of Food Hygiene and Safety
• /
• v.37 no.2
• /
• pp.46-54
• /
• 2022

Known for its effectiveness in weight loss and diabetes prevention, Gymnema sylvestre products can be found in the US, Japanese, and Indian markets. However, the recommended dosage or safety of these products has not yet been proven. Therefore, development of an analytical method for detecting the content of Gymnema sylvestre in food products is required. Accordingly, this study proposes an analysis method that can examine Gymnema sylvestre in food using LC-ESI-MS/MS and KASP (Kompetitive Allele-Specific PCR) markers. In LC-ESI-MS/MS, a simultaneous analysis method for gymnemic acid and deacylgymnemic acid was optimized using negative ionization mode, and its validation test was completed for solid and liquid samples. In addition, KASP markers were prepared by finding the specific SNP of G. sylvestre in ITS2 and matK through DNA barcodes. The two KASP markers returned positive FAM fluorescence result when combined with G. sylvestre, and this aspect was confirmed in raw G. sylvestre as well. The applicability of the method was tested on 21 different food and healthy functional products containing G. sylvestre purchased on the internet. As a result, although there was a difference in the ratios of gymnemic acid and deacylgymnemic acid in LC-ESI-MS/MS, the index component was detected in all 21 products samples. In the KASP analysis, 9 products returned positive FAM result, and the rest of the products were found to be containing G. sylvestre extract. This study is the first study to use the dual system of LC-ESI-MS/MS and KASP for the analysis of G. sylvestre. The study has confirmed that these two methods are applicable to the examine G. sylvestre content in food products.

• Korean Journal of Ecology and Environment
• /
• v.55 no.1
• /
• pp.84-98
• /
• 2022

Estuary is important in terms of biodiversity because it has the characteristics of transition waters, created by the mixing of fresh- and seawater. The estuarine water circulation provides a variety of habitats with different environments by inducing gradients in the chemical and physical environment, such as water quality and river bed structure, which are ultimately the main factors influencing biological community composition. If the water circulation is interrupted, the loss of brackish areas and the interception of migration of biological communities will lead to changes in the spatial distribution of biodiversity. In this study, among the sites covered by the Estuary Aquatic Ecosystem Health Assessment, we selected study sites where changes in biodiversity can be assessed by spatial gradient from the upper reaches of the river to the lower estuarine area. The α-, γ- and β-diversity of diatom, benthic macroinvertebrates, and fish communities were calculated, and they were divided into open and closed estuary data and compared to determine the trends in biodiversity variation due to estuarine circulation. As results, all communities showed higher γ-diversity at open estuary sites. The benthic macroinvertebrate community showed a clear difference between open and closed estuaries in β-diversity, consequently the estuarine transects were considered as a factor that decreases spatial heterogeneity of their diversity among sites. The biodiversity trends analyzed in this study will be used to identify estuaries with low γ- and β-diversity by community, providing a useful resource for further mornitoring and management to maintain estuarine health.