• Korean Journal of Animal Reproduction
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• v.22 no.4
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• pp.405-410
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• 1998

Boar semen extender Kp (Hankook Life-Science, Korea) was newly formulated by authors. This study was carried out to investigate the optimal concentrations of EDTA, Tris and citrate buffers in the Kp extender (Basic Kp) on the pH change during storage. And then the motility of boar sperm with the Kp pH stabilized (Modified Kp) was compared with those of commercial products imported into Korea such as BTS (Mini-tube. Germany; BTSg), BTS (Tri-bio, USA; BTSa) and Modena (SGI, USA). The pH values of all extenders were increased gradually with the storage days. Especially, the initial pH of Basic Kp was higher than that of BTSg, BTSa and Modena, and also higher than physiological pH of boar sperm (6.8∼7.5). When Basic Kp was added with various concentrations of EDTA (0, 0.63, 1.25 ＆ 2.37g/L), Tris (0, 0.18, 0.35, 0.71 ＆ 1.42g/L) and Citrate (0, 0.75, 0.81, 1.00, 1.25 ＆ 1.50g/L) buffers for pH down-regulation and stabilization of pH, the group added with 1.25g EDTA, 1.42g Tris and 1.00g Citrate well maintained the neutral range of pH during storage (6.88 at day1 to 7.33 at day6 in Modified Kp), Especially, the concentrations of the buffers added in Modified Kp were lower, until 1/2∼1/4 ranges, than those in Modena and other extenders. The motility of frozen-thawed boar sperm diluted with Modified Kp was significantly higher than that of Basic Kp, BTSg, BTSa and Modena (87.0% vs. 55.0∼71.0% at day1; 13.3% vs. 0∼6.3% at day6), Conclusively, Modified Kp in this experiment was kept the favorable physiological conditions in spite of low concentrations of the buffers and motility of frozen-thawed boar sperm was obtained better than that of Basic Kp and other commercial products such as BTSg, BTSa and Modena.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.1-10
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• 2020

The present study identified the restrictions on the use of sous-vide products in the Korean HMR market for small and medium-sized manufacturing companies. A detailed literature review revealed that the HMR market in Korea is close to saturation. Notably, the technologically advanced products produced using sous-vide seem to display significant potential to overcome market saturation. The sous-vide method differs from conventional cooking techniques and is characterized by maintenance of food texture along with flavor enhancement. However, due to the unfamiliarity of the manufacturers with this method and the unclear food safety regulations, mass food manufacturing companies do not agree on using this method; hence, sous-vide production is usually undertaken by small/medium sized companies catering primarily through online marketing portals. This study highlights the various restrictions to the implementation of sous-vide production, and discusses several practical implications of sous-vide production that would help users of this technique enter the HMR market.

• Korean Journal of Food Science and Technology
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• v.44 no.6
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• pp.763-771
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• 2012

In this study, total antioxidant properties of extracts from different parts of Lespedeza bicolor were determined using techniques of measuring 1,1-diphenyl-2-picryl hydrazyl/2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)-radical scavenging activity and total phenolic contents. The total antioxidant activities of leaf, stem and root extracts from various solvents (water, 50, 70, 100% ethanol, and hot-water) indicated that 50 and 70% ethanol extracts have high radical scavenging activities and phenolic contents. A systematic approach was used to determine the total antioxidant activity of different solvent fractions of the Lespedeza bicolor extracts, partitioning with chloroform, ethyl acetate, n-butanol, and water, and the ethyl acetate fraction was found to have the strongest antioxidant activity. Antioxidant assay-guided isolation was carried out to isolate potential antioxidant compounds. The ethyl acetate fraction of the leaf extract was subjected to silica gel, LH-20 and RP-18 column chromatography successively, and afforded compound 1, which was identified as eriodictyol by NMR and MS analysis, after which its antioxidant activity was determined.

• Restorative Dentistry and Endodontics
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• v.24 no.2
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• pp.299-309
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• 1999

The composite resin, due to its esthetic qualities, is considered the material of choice for restoration of anterior teeth. With respect to shade control, the direct-placement resin composites offer some distinct advantages over indirect restorative procedures. Visible-light-cured (VLC) composites allow dentists to match existing tooth shades or to create new shades and to evaluate them immediately at the time of restoration placement. Optimal intraoral color control can be achieved if optical changes occurring during application are minimized. An ideal VLC composite, then, would be one which is optically stable throughout the polymerization process. The shade guides of the resin composites are generally made of plastic, rather than the actual composite material, and do not accurately depict the true shade, translucency, or opacity of the resin composite after polymerization. So the numerous problems associated with these shade guides lead to varied and sometimes unpredictable results. The aim of this study was to assess the color changes of current resin composite restorative materials which occur as a result of the polymerization process and to compare the color differences between the shade guides provided with the products and the actual resin composites before- and after-polymerization. The results obtained from this investigation should provide the clinician with information which may aid in improved color match of esthetic restoration. Five light activated, resin-based materials (${\AE}$litefil, Amelogen Universal, Spectrum TPH VeridonFil-Photo, and Z100) and shade guides were used in this study. Three specimens of each material and shade combination were made. Each material was condensed inside a 1.5mm thick metal mold with 10mm diameter and pressed between glass plates. Each material was measured immediately before polymerization, and polymerized with Curing Light XL 3000 (3M Dental products, USA) visible light-activation unit for 60 seconds at each side. The specimens were then polished sequentially on wet sandpaper. Shade guides were ground with polishing stones and rubber points (Shofu) to a thickness of approximately 1.5mm. Color characteristics were performed with a spectrophotometer (CM-3500d, Minolta Co., LTD). A computer-controlled spectrophotometer was used to determine CIELAB coordinates ($L^*$, $a^*$ and $b^*$) of each specimen and shade guide. The CIELAB measurements made it possible to evaluate the amount of the color difference values (${\Delta}E{^*}ab$) of resin composites before the polymerization process and shade guides using the post-polishing color of the composite as a control, CIE standard D65 was used as the light source. The results were as follows. 1. Each of the resin composites evaluated showed significant color changes during light-curing process. All the resin composites evaluated except all the tested shades of 2100 showed unacceptable level of color changes (${\Delta}E{^*}ab$ greater than 3.3) between pre-polymerization and post-polishing state. 2. Color differences between most of the resin composites tested and their corresponding shade guides were acceptable but those between C2 shade of ${\AE}$litefil and IE shade of Amelogen Universal and their respective shade guides exceeded what is acceptable. 3. Comparison of the mean ${\Delta}E{^*}ab$ values of materials revealed that Z100 showed the least overall color change between pre-polymerization and post-polishing state followed by ${\AE}$litefil, VeridonFil-Photo, Spectrum TPH, and Amelogen Universal in the order of increasing change and Amelogen Universal. Spectrum TPH, 2100, VeridonFil-Photo and ${\AE}$litefil for the color differences between actual resin and shade guide. 4. In the clinical environment, the shade guide is the better choice than the shade of the actual resin before polymerization when matching colors. But, it is recommended that custom shade guides be made from resin material itself for better color matching.

• Food Science and Preservation
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• v.25 no.1
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• pp.145-154
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• 2018

The purpose of this study was to investigate the ability of natural antioxidants as stabilizers for meat by-products to prevent lipid oxidation. The white internal organs were evaluated using different treatments: no antioxidant (control), ascorbic acid (T1), Artemisiacapillaris Thunb. (T2), Opuntia (T3), Schisandra chinensis (T4), and Saururuschinensis (Lour.) Baill (T5). Antioxidant activities were analyzed by measuring DPPH contents, superoxide anion radical levels, nitrate scavenging activities, and total polyphenol contents. T1 and T2 showed higher antioxidant activities and total polyphenol contents (p<0.05). Additionally, changes in physicochemical properties (pH, color, volatile basic nitrogen [VBN], and thiobarbituric acid reactive substances [TBARS]) and microbiological aspects in white internal organs processed with antioxidants were investigated. As storage time increased, the CIE $a^*$ and $b^*$ values of the white internal organs processed with natural antioxidants were decreased (p<0.05), and CIE $L^*$ values were low, particularly for the T3 sample relative to that in the control. Moreover, the pH, VBN, and TBARS values of samples T2-T5 were increased after 7 days of storage, but showed low values compared with those of the control (p<0.05). Moreover, compared with the control group, the treatments showed antimicrobial effects. Our results indicated that these natural antioxidants could be used as lipid oxidation stabilizers of meat by-products during storage and that Artemisiacapillaris Thunb. and Opuntia may have applications as natural antioxidants in the meat by-product industry.

• Korean Journal of Food Science and Technology
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• v.15 no.2
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• pp.141-149
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• 1983

The purpose of the present work is to find out the optimal conditions for the production of filefish protein preparations and to define the functional properties of the protein products. Fish protein concentrate (FPC) and fish protein isolate (FPI) were prepared by extraction of whole or headed and gutted filefish with various organic solvents. The results of the present study are as follows; 1. Among the solvents tested iso-propyl alcohol appeared to be the most effective for the extraction of lipid and also for that trimethylamine from the fish muscle. 2. The optimal extraction time showed to be 20 minutes with ethyl iso-propyl alcohol at $65-70^{\circ}C$under adequate mixing. 3. The most effective solvent ratio to the weight of fish material was proved to be 5:1 at the first extraction and to be 2:1 at the second stage. 4. The lipid content of the protein preparations reduced to below 0.5% by the third stage of extraction of headed or gutted filefish. The protein concentrate from whole fish, however, showed the lipid content of 0.27-0.31% only after the fifth stage of extration. 5. The protein contents of the protein concentrate and the protein isolate from whole filefish were 81.08% and 87.41% and the lipid contents of the two protein preparations were 0.43% and 0.45% respectively. 6. Higher calcium content was found in the protein concentrate rather than in the protein isolate. No sodium and potassium in the protein isolate were detected while the fish concentrate appeared to contain a considerable amounts of both elements. 7. The functional properties, such as suspended solids, wetability, emulsion stability and foam viscosity of the filefish protein isolates were proved to be higher than those of the protein concentrate.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.945-951
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• 1999

A simple and practical method for the determination of gardenia yellow in foods was developed. In this method, analysis of gardenia yellow in food products has been carried out by the detection of crocetin and/or geniposide as indicator compounds. As a new analytical method for gardenia yellow, we adopted crocetin, which is produced from colored components of gardenia yellow by alkaline hydrolysis, as an indicator compound. The analysis of gardenia yellow was performed by reverse phase high performance liquid chromatography using a Capcell pak $C_{18}$ column at wave length 240 nm (geniposide) and 435 nm (crocetin). The recovery rates of geniposide and crocetin were found to be 93.4% and 87.8% for Dan Mu Ji, 90.2% and 85.9% for milk, 92.8% and 86.5% for snack, respectively. With this method, the range of crocetin and geniposide contents $({\mu}g/g)$ were as follows: $ND{\sim}1.7$ and $ND{\sim}14.1$ for Dan Mu Ji, $ND{\sim}0.2$ and $ND{\sim}13.6$ for milk, $ND{\sim}1.6$ and $ND{\sim}0.9$ for snack, respectively. The detection limits of crocetin and geniposide were 0.07 ${\mu}g/g$ and 0.05 ${\mu}g/g$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1165-1170
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• 2010

A method for the determination of four pesticide compounds, urea (isoproturon), bis-carbamate (phenmedipham), thiocarbamate (pyridate) and vinyllidenediamine (nitenpyram) were examined and analyzed by HPLC with C-18 column ($250\;mm{\times}4.6\;mm$, $5\;{\mu}m$ diameter particle size). Mobile phase consisted of deionized water, acetonitrile and 50 mM $KH_2PO_4$ (pH 2.5). Isoproturon and phenmedipham analytical condition was isocratic elution of the column with 50% solvent A (acetonitrile) and 50% solvent B (deionized water); pyridate was 85% solvent A (acetonitrile) and 15% solvent B (deionized water) at a flow rate of 1 mL/min; and nitenpyram analytical condition was 90% solvent A (50 mM $KH_2PO_4$, pH 2.5) and 10% solvent B (acetonitrile) at a flow rate of 1 mL/min. In results, retention times were 6.12, 8.63, 9.40 and 12.76 min for isoproturon, phenmedipham, pyridate and nitenpyram, respectively. All injection volumes were $10\;{\mu}L$ and the limit of quantitation was 0.05 mg/kg for four pesticide compounds, respectively. Recovery rate test was performed with three farm products, rice, apple and soybean. Four pesticide compounds were spiked at concentrations of 0.05, 0.1 and 0.5 mg/kg. The recovery rates were ranged from 70.18% to 118.08% and the standard deviations of all experiments were within 10%.

• The Korean Journal of Mycology
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• v.13 no.3
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• pp.157-168
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• 1985

To investigate nutritive values of a feed fermented with basidiomycetes, among the isolated strains, Lyophyllum decastes (Fr.) Sing. was found with the greatest enzyme productivity and rapid mycelial growth in rice straw medium. Optimum temperature, pH and moisture content for mycelial growth and enzyme production of the strain were $25{\sim}30^{\circ}C,\;pH\;4.0{\sim}7.0\;and\;70{\sim}75\;%$, respectively. Fifteen days of culture were required for the highest enzyme productivity. Among the sub-materials added, $30{\sim}40\;%$ of rice bran and $10{\sim}20\;%$ of defatted perilla seeds were effective for the enzyme production, but caused a reduced mycelial growth. The greatest effect of an addition of inorganic salts was obtained with $0.36{\sim}0.72\;%\;of\;(NH_4)_2HPO_4$. When 40 mesh or smaller rice straw and steam treatment at $0.5\;kg/cm^2$ were used, the mycelial growth decreased, whereas the enzyme production increased. The mycelial growth and enzyme production increased when $Ca(OH)_2$ was used as the alkali treatment, but decreased with increasing concentration of NaOH. As the fermentation proceeded, the amounts of ash, reducing sugar and total nitrogen increased, but cellulose, lignin and pentosan decreased. When the rice straw was treated with alkali, the amounts of ash, total nitrogen and lignin decreased, but reducing sugar and cellulose increased. At higher NaOH concentration, the variation become greater. The in vitro dry matter digestibility of the products increased from 55.03 % at the beginning of the fermentation to 62.72 % at 45 days after fermentation. The most effective alkali treatment on the digestibility of rice straw was KOH followed by NaOH. However, the digestibility increased with increasing concentration of NaOH. The digestibility of pretreated with alkali increased after fermentation as well.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.228-234
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• 2012

The varying characteristics between traditional and commercial soy sauce may be initiated by raw materials and fermentation techniques for the production of $meju$ and $koji$. We examined properties regarding polysaccharides isolated from commercial soy sauce made by the $koji$ process (CSP-0) and Korean traditional soy sauce made by the $meju$ process (KTSP-0) as well as their immuno-stimulating activities. KTSP-0 had rhamnogalacturonan II (RG-II) including 1.1% of unusual monosaccharides 3-deoxy-D-$manno$-2-octulosonic acid (KDO). Anti-complementary activities of CSP-0 and KTSP- 0 were increased dose-dependently but KTSP-0 (64.7%) was higher than CSP-0 (56%) at $1,000{\mu}g/mL$. C3 activation products were identified by crossed immuno-electrophoresis. CSP-0 caused complementary activations $via$ only classical pathway while KTSP-0 caused complementary activations $via$ both alternative and classical pathways. KTSP-0 significantly increased the secretion of interleukin (IL)-6 at $8-1,000{\mu}g/mL$ and IL-12 at $40{\mu}g/mL$ on macrophages. The results suggest that the immuno-stimulating activity of KTSP-0 is greater than that of CSP-0 from anti-complementary activity.