• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1527-1527
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• 2001

Glucose, fructose and sucrose being the main sugars that can be found in natural fruit juice. Many instrumental methods, such as GC, LC, electrochemical or spectrometric methods provide information about both the total content of sugars and the specific concentration of each carbohydrate[1]. The simplicity of sample handling and measurement in the near IR(NIR) wavelength region, which allows the use of long pathlength, optical glass cells and optical fibers, makes NIR a good alternative for sugar determination [2]. In the present study, six varieties of persian grapes were harvested at intervals through august to october and analysed for sugars by NIR. The results were processed by principal component regression (PCR) and partial least squares (PLS) analysis. Sample juice was prepared by squeezing through gauze from crashed grape. This solution was treated by zinc ferrocyanide prior to analysis in order to eliminate colored compounds and all optically active nonsugar substances. For glucose and fructose the most characteristic wavelengths were 1456nm corresponding to the first harmonic O-H stretching and the second at 2062nm corresponding to O-H stretching and deformation; secondary characteristic combination bands were also seen at 2265 nm (O-H and C-C stretching) and at 2240 nm (C-H and C-C stretching). However these spectra were taken over a wavelength range from 1100-2500nm at room temperature of 25-$30^{\circ}C$. To test the accuracy of the described procedure, samples of six varieties of grape were analysed by the proposed NIR and a standard method[2]. Good agreement were found between these two sets of the results. To perform the recovery studies , samples of grape juices previously analysed by the proposed method, were spiked with known amounts of each individual sugars and then analysed again. Relative standard deviations varied from 1.4 to 1.8% for six independent measurements of individual and total sugar concentration. In the analysis of real and synthetic samples, precise and accurate results were obtained , providing accuracy errors lower than 1.9% in all cases. Average recoveries of ${97}{\pm}{4%}$ for total sugar and between ${95}{\pm}{5%}$ and ${99}{\pm}{2%}$ for sing1e sugars demonstrate the applicability of the methodology developed to the direct analysis of grape Juice.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1128-1131
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• 1999

Antioxidative and antimicrobial effects of the extracts of Castanea crenata leaf tea, steamed tea and semi-fermented tea were investigated. Antioxidative effects were by measuring the 1,1-diphenyl-2-picrylhydrazyl(DPPH)-radical scavening activity of the extracts. The effects were stronger than that of synthetic antioxidant such as BHT at the same concentration. The $SC_{50}$ value (50% radical scavening effects of $1{\times}10^{-4}$ M DPPH) of steamed tea, semi-fermented tea and BHT were 53.3 ${\mu}g/mL$, 49.9 ${\mu}g/mL$ and 101.0 ${\mu}g/mL$, respectively. The antimicrobial effects of methanol extracts (8 mg, 20 mg) of 0.2 g and 0.5 g. eq. of Castanea crenata leaf tea were stronger than those of 0.65 mg of benzoic acid, against gram(+) bacteria such as S. aureus, S. epidermidis, M. luteus, L. mesenteroides and B. subtilis and gram(-) bacteria such as E. coli, S. typhimurium, and P. aeruginosa.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.595-601
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• 2014

The microstructures of NATM were examined by SEM, FT-IR spectra, tensile properties, mole % of [NCO/OH], and particle size analyzer. Growing concerns in the environment-friendly industries have led to the development of solvent-free formulations that can be cured. We had synthesized NATM(New Austria Tunnel Method) resin having the ability to protect stainless steel against corrosion. Comparing with general NATM resin and coatings, this resin that synthesized with polyurethane and epoxy was highly stronger in intensity and longer durability. Hybrid resin was composed of polyols, MDI, epoxy, silicone surfactant, catalyst and crosslink agent, and fillers. Moreover, fillers such as fume silica not only accelerated the curing rate but also improved the physical property as thermal barriers. The rigid segments of synthetic resin in mechanical properties were due to fume silica and the increase the mole% of [NCO/OH] for corrosion protection. In conclusion, the hybrid resin microstructure with crosslink agent and fume silica are good material for thermosetting coating of metal substrates such as stainless steel.

• Journal of the Korean Chemical Society
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• v.36 no.2
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• pp.318-323
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• 1992

Following seven new nucleophilic adducts of sulfilimine compounds were prepared by the addition of 1-methyl-5-mercapto-1,2,3,4-tetrazole to vinylsulfilimine derivatives; S-Phenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-p-tolyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-m-tolyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-p-chlorophenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-p-bromophenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-p-methoxyphenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine and S-p-nitrophenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine. The structures of these adducts were confirmed by elemental analyses, MP, UV, IR-and NMR-Spectra.

• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.5-6
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• 2002

The new spectrometer for X-ray Induced Electron Emission Spectroscopy (XIEES) .has been recently developed in KRISS in collaboration with PTI (Russia). The spectrometer allows to perform research using the XAFS, SXAFS, XANES techniques (D.C.Koningsberger and R.Prins, 1988) as well as the number of techniques from XIEES field(L.A.Bakaleinikov et all, 1992). The experiments may be carried out with registration of transmitted through the sample x-rays (to investigate bulk samples) or/and total electron yield (TEY) from the sample surface that gives the high (down to several atomic mono-layers in soft x-ray region) near surface sensitivity. The combination of these methods together give the possibility to obtain a quantitative information on elemental composition, chemical state, atomic structure for powder samples and solids, including non-crystalline materials (the long range order is not required). The optical design of spectrometer is made according to Johannesson true focusing schematics and presented on the Fig.1. Five stepping motors are used to maintain the focusing condition during the photon energy scan (crystal angle, crystal position along rail, sample goniometer rail angle, sample goniometer position along rail and sample goniometer angle relatively of rail). All movements can be done independently and simultaneously that speeds up the setting of photon energy and allows the using of crystals with different Rowland radil. At present six curved crystals with different d-values and one flat synthetic multilayer are installed on revolver-type monochromator. This arrangement allows the wide range of x-rays from 100 eV up to 25 keV to be obtained. Another 4 stepping motors set exit slit width, sample angle, channeltron position and x-ray detector position. The differential pumping allows to unite vacuum chambers of spectrometer and x-ray generator avoiding the absorption of soft x-rays on Be foil of a window and in atmosphere. Another feature of vacuum system is separation of walls of vacuum chamber (which are deformed by the atmospheric pressure) from optical elements of spectrometer. This warrantees that the optical elements are precisely positioned. The detecting system of the spectrometer consists of two proportional counters, one scintillating detector and one channeltron detector. First proportional counter can be used as I/sub 0/-detector in transmission mode or by measuring the fluorescence from exit slit edge. The last installation can be used to measure the reference data (that is necessary in XANES measurements), in this case the reference sample is installed on slit knife edge. The second proportional counter measures the intensity of x-rays transmitted through the sample. The scintillating detector is used in the same way but on the air for the hard x-rays and for alignment purposes. Total electron yield from the sample is measured by channeltron. The spectrometer is fully controlled by special software that gives the high flexibility and reliability in carrying out of the experiments. Fig.2 and fig.3 present the typical XAFS spectra measured with spectrometer.

• Korean Chemical Engineering Research
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• v.44 no.2
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• pp.172-178
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• 2006

Mesoporous silicate materials have been used as adsorbents for the removal of heavy metals from water by introducing functional groups such as thiol and amine. In this research, it was investigated whether surfactants used as templating agents in synthetic processes can act as adsorption sites for heavy metals. Three mesoporous silicates-SBA-15, MCM-41, and HMS were synthesized using, respectively, block copolymer, hexadecyltrimethylammoniumbromide (HDTMA), and dodecyamine as surfactants. X-ray diffraction and $N_2$ gas adsorption analysis confirmed that the mesoporous silicates were well prepared and FT-IR spectra resulted in the existence of the surfactants in as-synthesized mesoporous silicates and the removal of surfactants after calcination. The interactions between $Pb^{2+}$ ions and the mesoporous silicate materials with/without surfactants were observed. In adsorption kinetic experiments, it revealed that the calcined mesoporous silicates and the surfactant-loaded SBA-15 almost had no adsorption capacity for $Pb^{2+}$ ions. In contrast, the surfactant-loaded MCM-41 and HMS showed, respectively, the adsorption capacities of 26.60 and 115.16 mg/g which were acquired through the fits of adsorption kinetic data to the pseudo second order kinetic model. The adsorption capacities were comparable to those of other mesoporous adsorbents for heavy metals.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.319-326
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• 2014

Two bacterial strains, named as LE17 and LE22, were isolated from traditionally fermented soybean products in order to select lactic acid bacteria for the reduction of biogenic amines and harmful bacteria. Both strains were identified as Pediococcus pentosaceus by 16S rRNA sequence analysis and additional biochemical tests. The strain LE17 reduced the amines by 13.7% for histamine and by 25.9% for tyramine, when it grew in minimal synthetic media containing 0.1% (w/v) histamine and 0.1% tyramine at $30^{\circ}C$ for 48 h, while the strain LE22 reduced the amines by 23.7% for histamine and by 15.7% for tyramine. Both strains also had broad inhibition spectra against pathogens. Considering their properties, they could be used as starters for industrial soybean fermentation.

• 한국유가공학회:학술대회논문집
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• 2002.04a
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• pp.59-60
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• 2002

Edible films such as wax coatings, sugar and chocolate covers, and sausage casings, have been used in food applications for years$^{(1)}$ However, interest in edible films and biodegradable polymers has been renewed due to concerns about the environment, a need to reduce the quantity of disposable packaging, and demand by the consumer for higher quality food products. Edible films can function as secondary packaging materials to enhance food quality and reduce the amount of traditional packaging needed. For example, edible films can serve to enhance food quality by acting as moisture and gas barriers, thus, providing protection to a food product after the primary packaging is opened. Edible films are not meant to replace synthetic packaging materials; instead, they provide the potential as food packagings where traditional synthetic or biodegradable plastics cannot function. For instance, edible films can be used as convenient soluble pouches containing single-servings for products such as instant noodles and soup/seasoning combination. In the food industry, they can be used as ingredient delivery systems for delivering pre-measured ingredients during processing. Edible films also can provide the food processors with a variety of new opportunities for product development and processing. Depends on materials of edible films, they also can be sources of nutritional supplements. Especially, whey proteins have excellent amino acid balance while some edible films resources lack adequate amount of certain amino acids, for example, soy protein is low in methionine and wheat flour is low in lysine$^{(2)}$. Whey proteins have a surplus of the essential amino acid lysine, threonine, methionine and isoleucine. Thus, the idea of using whey protein-based films to individually pack cereal products, which often deficient in these amino acids, become very attractive$^{(3)}$. Whey is a by-product of cheese manufacturing and much of annual production is not utilized$^{(4)}$. Development of edible films from whey protein is one of the ways to recover whey from dairy industry waste. Whey proteins as raw materials of film production can be obtained at inexpensive cost. I hypothesize that it is possible to make whey protein-based edible films with improved moisture barrier properties without significantly altering other properties by producing whey protein/lipid emulsion films and these films will be suitable far food applications. The fellowing are the specific otjectives of this research: 1. Develop whey protein/lipid emulsion edible films and determine their microstructures, barrier (moisture and oxygen) and mechanical (tensile strength and elongation) properties. 2. Study the nature of interactions involved in the formation and stability of the films. 3. Investigate thermal properties, heat sealability, and sealing properties of the films. 4. Demonstrate suitability of their application in foods as packaging materials. Methodologies were developed to produce edible films from whey protein isolate (WPI) and concentrate (WPC), and film-forming procedure was optimized. Lipids, butter fat (BF) and candelilla wax (CW), were added into film-forming solutions to produce whey protein/lipid emulsion edible films. Significant reduction in water vapor and oxygen permeabilities of the films could be achieved upon addition of BF and CW. Mechanical properties were also influenced by the lipid type. Microstructures of the films accounted for the differences in their barrier and mechanical properties. Studies with bond-dissociating agents indicated that disulfide and hydrogen bonds, cooperatively, were the primary forces involved in the formation and stability of whey protein/lipid emulsion films. Contribution of hydrophobic interactions was secondary. Thermal properties of the films were studied using differential scanning calorimetry, and the results were used to optimize heat-sealing conditions for the films. Electron spectroscopy for chemical analysis (ESCA) was used to study the nature of the interfacial interaction of sealed films. All films were heat sealable and showed good seal strengths while the plasticizer type influenced optimum heat-sealing temperatures of the films, 130$^{\circ}$C for sorbitol-plasticized WPI films and 110$^{\circ}$C for glycerol-plasticized WPI films. ESCA spectra showed that the main interactions responsible for the heat-sealed joint of whey protein-based edible films were hydrogen bonds and covalent bonds involving C-0-H and N-C components. Finally, solubility in water, moisture contents, moisture sorption isotherms and sensory attributes (using a trained sensory panel) of the films were determined. Solubility was influenced primarily by the plasticizer in the films, and the higher the plasticizer content, the greater was the solubility of the films in water. Moisture contents of the films showed a strong relationship with moisture sorption isotherm properties of the films. Lower moisture content of the films resulted in lower equilibrium moisture contents at all aw levels. Sensory evaluation of the films revealed that no distinctive odor existed in WPI films. All films tested showed slight sweetness and adhesiveness. Films with lipids were scored as being opaque while films without lipids were scored to be clear. Whey protein/lipid emulsion edible films may be suitable for packaging of powder mix and should be suitable for packaging of non-hygroscopic foods$^{(5,6,7,8,)}$.