• Korean Journal of Microbiology
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• v.49 no.3
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• pp.228-236
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• 2013

Campylobacter jejuni is one of important food-borne pathogens causing human gastroenteritis. We isolated 42 strains of C. jejuni from diarrhea patients and 4 food-poisoning outbreaks in 2010, Gyeonggi-do. In this study, 42 strains were tested for genetic characteristics, the serotype distribution and antimicrobial resistant rate. The presence of hipO (100%), cdtB (100%), and mutated gyrA (95.2%) genes was detected in C. jejuni by polymerase chain reaction (PCR). Detection of mutated gyrA gene correlated with ciprofloxacin resistance. Forty isolates had mutated gyrA gene and were actually resistant to ciprofloxacin. Furthermore, comparing the gyrA DNA sequence data, ciprofloxacin-resistant isolates had a mutation of the DNA sequence from ACA (threonine) to ATA (isoleucine). But 41 strains (97.6%) of patient isolates were susceptible to erythromycin and azithromycin. A total of 35.7% among 42 C. jejuni isolates were identified into 4 different serotypes. The serotype distribution of C. jejuni strains were shown to be HS2(B), HS3(C), HS4(D), HS19(O). To investigate the genotypes of C. jejuni isolated in Gyeonggi province, repetitive sequence polymerase chain reaction (rep-PCR) analysis and SmaI-digested pulsed-filed gel electrophoresis (PFGE) profile analysis were performed. From the PFGE analysis of 42 C. jejuni strains, 12 clusters of PFGE profile were obtained. On the other hand, 11 clusters of rep-PCR profile were obtained from 42 strains of C. jejuni.

• Tunnel and Underground Space
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• v.13 no.1
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• pp.52-63
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• 2003

Discontinuities such as faults, fractures and joints in rock mass play the dominant role in the mechanical and hydraulic properties of the rock mass. The key factors that influence on the flow of groundwater are hydraulic and geometric characteristics of discontinuities and their connectivity. In this study, a program that analyzes groundwater flow in the 3D discontinuity network was developed on the assumption that the discontinuity characteristics such as density, trace length, orientation and aperture have particular distribution functions. This program generates discontinuities in a three-dimensional space and analyzes their connectivity and groundwater flow. Due to the limited computing capacity In this study, REV was not exactly determined, but it was inferred to be greater than 25$\times$25$\times$25 ㎥. By calculating the extent of aperture that influences on the groundwater flow, it was found that the discontinuities with the aperture smaller than 30% of the mean aperture had little influence on the groundwater flow. In addition, there was little difference in the equivalent hydraulic conductivity for the the two cases when considering and not considering the boundary effect. It was because the groundwater flow was mostly influenced by the discontinuities with large aperture. Among the parameters considered in this study, the length, aperture, and orientation of discontinuities had the greatest influence on the equivalent hydraulic conductivity of rock mass in their order. In case of existence of a fault in rock mass, elements of the equivalent hydraulic conductivity tensor parallel to the fault fairly increased in their magnitude but those perpendicular to the fault were increased in a very small amount at the first stage and then converged.

• 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$^{(5,6,7,8,)}$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.1
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• pp.97-104
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• 2002

Protein hydrolysate was prepared as a natural flavor stock from the sharp toothed eel (Muraenesox cinereus) mince using com-mercially available proteolytic enzymes, Alcalase, Neutrase, Protamex, and Flavourzyme. A 6 hr hydrolysis of mince, to which water of the equal weight of the mince was added, with $2\%$ (w/w, protein weight) Elavourzyme at $50^{\circ}$ yielded a hydrolysate of the highest acceptability. Removing the access lipid in liquified hydrolysate (not dehydrated) after enzyme hydrolysis, five times repetitive extraction using n-hexane (liquified hydrolysate : n-hexane=4 : 1, v/v) was effective, resulting in less than $1\%$ lipid content of the dehydrated-hydrolysate. The amino acid composition of the hydrolysate (prepared with Flavourzyme) was similar to that of the starting material. Hydrolysis led to an increase in concentration of not only total free amino acid but also free amino acid such as serine, glutamic acid, alanine, and methionine responsible for umami taste, especially up to about 40 times for methionine. Major free amino acids in amount were leucine, phenylalanine, valine, alanine, and isoleucine and they comprised about half of the total free amino acids, Moisture adsorption, fat adsorption, emulsifying capacity, and foaming capacity of the hydrolysate were 870.1 $\pm$ $7.9\%$, 352.0$\pm$ $5.3\%$, 50.3 $\pm$ $1.2\%$, and $87.5\pm$ $2.5\%$, respectively, and solubility was 83$\~$$84\%$ at acid pH range of 2$\~$4.

• Journal of Nutrition and Health
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• v.29 no.8
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• pp.889-898
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• 1996

This study estimated the re!ation between psychological stress and stress hormones, nu­t tritional status of patients with non-insulin dependent diabetes mellitus(NIDDM). Psycho­l logical stress such as depr'ession and anxiety in 34 diabetics was analyzedin relation to nutrient intake, blood components such as fasting blood sugar(FBS), hemoglobin AIC, stress hormones a and amino acids. The IeveIs of depression and anxiety were measured by The center for ep­i idemiological studies-depc$pm$111.49pg/ml for total catecholamine ( (norepmephrine and epinephrine) and 233.95 $pm$73.99pg/ml for norepinephrine, 94.03$pm$75. 9 97pg/ml for epinephrine, 13.lS$pm$5.55pl/dl for cortisol and 171.50$pm$62.50pg/ml for gul c cagon respectlveIy. The leveIs of stress hormones in diabetics such as total catecholamine, norep­i mephrine cortisol and glucagon were significantly higher than those in normal control. The lev­el of epmephrine was higher in diabetics but the diffierenee was not significant. The calorie m t take in diabetics was 1762$pm$292keal which is S1.4% lower than Korean recommended dietary a allowances(RDA). Calcium intake was slightly low but other nutrients intakeswere higher than R RDA. The value of fasting blood sugar(FBS), usual fasting blood sugar(usual FBS) which refteet a average FBS during 3 months and hemoglobin Al C in diabetics was 1S4.1S$pm$74.22mg/dl, 177.76$pm$42.77mg/dl and S.S4$pm$2.S2% respec디VeIy. The distribution of plasma amino acids in d diabetics was generally in the normal range. The leveI of anxiety in diabetics was positively cor­related with norepinephrine, concentration and usual FBS. The levels of glucagon, usual FBS a and hemoglobin Aj C were pOSI디veIy correlated with the branched chaimamino acid(BCM : leucme, isoleucme and valine)

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.912-918
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• 1999

The chemical compositions of korean and Chinese safflower (Carthamus tinctorious L.) seed were compared in this study. The proximate compositions were 0.73 and 0.05% of moisture, 19.74 and 18.82% of crude protein, 15.47 and 14.61% of crude fat, 3.78 and 3.87% of crude ash, 14.53 and 10.46% of crude fiber, 46.49 and 52.23% of N-free extracts in the non-roasted safflower seed (NRS) and roasted safflower seed (RS), respectively. Crude fat contents in non-roasted chinese safflower seed (NRCS) and roasted chinese safflower seed (RCS) were 33.30 and 31.22%, which were higher than those of NRS and RS. Unsaturated fatty acid in NRS was 83.2% and 90.9% in NRCS. Linoleic acid was the most predominant fatty acid in NRS (74.0%) and NRCS (74.2%). Sucrose (216.5 mg/100 g) and raffinose (117.5 mg/100 g) were major free sugars in NRS, but sucrose, glucose, fructose and raffinose were in NRCS. Glutamic acid, aspatic acid and arginine were major in total amino acids. 24 kinds of free amino acid were detected in NRS and 11 kinds in RS. Total essential amino acid in NRS ($28.0\;{\mu}g/100\;g$) was higher than that in NRCS ($9.2\;{\mu}g/100\;g$). The organic acids in safflower seed were composed of formic acid, succinic acid, malic acid, oxalic acid and fumaric acid. The content of vitamin E $({\alpha}-tocopherol)$ in NRS and NRCS were 10.5 mg/100 g, 6.2 mg/100 g, NRCS and RCS were 12.8 mg/100 g, 9.4 mg/100 g, respectively. Total carotenoid content in NRCS was $452.0\;{\mu}g/100\;g$ and it was higher than in NRS. The major minerals of safflower seed were K, P, Ca, Mg.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.2
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• pp.178-184
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• 1990

The lipid components, nitrogenous extracts and amino acids of dark muscle(DM) of ski-pjack (Katsuwonus pelamis) were analyzed and compared with those of white muscle (WM). WM was higher in moisture and crude protein content, and lower in crude lipid and ash content than those of DM. Contents of volatile basic nitrogen in WM and DM were 22.7mg/100g and 46.9mg/100g. Total lipid(TL) of WM and DM consisted of $79.7\%,\;71.9\%$ neutral lipid(NL), $6.8\%,\;9.5\%$ glycolipid(GL), and $13.5\%,\;18.6\%$ phospholipid(PL), respectively NL was mainly com-posed of free fatty acid, triglyceride, and PL was mainly occupied by phosphatidyl ethanolamine, phosphatidyl choline. Also Iysophosphatidyl choline and Iysophosphatidyl ethanolamine were identified in PL. In fatty acid composition of TL, NL, GL and PL, WM revealed higher contents in saturates and monoenes such as 16 : 0, 18 : 1, while DM showed higher contents in polyenes such as 22 : 6 especially. The major fatty acids of these samples were generally 16: 0, 18:0, 18:1, 20:5 and 22 : 6. Contents of total free amino acids from WM and DM were 5,982.3mg/100g and 4,450.7 mg/100g (dry base). Of free amino acids, Tau concentration was much higher in DM than in WM, Ala, Gly, Met, Arg, Thr were also high in DM. But His was much higher in concentration in W. Content of inosinic acid(IMP) in WM(680.9mg/100g) was higher than that of DM(73.1mg/100g). The degradations of IMP proceeded very rapidly in DM. DM contained much higher trimethylamine oxide and trimethylamine than those of WM. The profile of combined amino acids in these samples, were very similar, and main amino acids were Glu, Asp, Lys, Ala, Ile and Arg.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.2
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• pp.79-110
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• 1976

In Korea fermented fish and shellfish have traditionally been favored and consumed as seasonings or further processed for fish sauce. Three major items in production quantity among more than thirty kinds which are presently available in the market are fermented anchovy, oyster and small shrimp. They are usually used as a seasoning mixture of Kimchi in order to provide a distinctive flavor. Fermented small shrimp, Acetes chinensis is most widely and largely used ana occupies an important position in food industry of this country. But no study on its taste compounds has been reported. This study was attempted to establish the basic data for evaluating taste compounds of fermented small shrimp. The changes of such compounds during fermentation as free amino acids, nucleotides and their related compounds, TMAO, TMA, and betaine were analysed. In addition, change in microflora during the fermentation under the halophilic circumstance was also investigated. The samples were prepared with three different salt contents of 20, 30 and $40\%$ to obtain the proper degree of fermentation at a controlled tempeature of $20{\pm}2^{\circ}C$. The results are summarized as follows: Volatile basic nitrogen increased rapidly until 108 days of fermentation and afterwards it tended to increase slowly. Amino nitrogen also increased rapidly until 43 days of fermentation and then increased slowly. Extract nitrogen increased and marked the maximum value at 72 day fermentation and then decreased slowly. ADP, AMP and IMP tended to degrade rapidly while hypoxanthine increased remarkably at 27 day fermentation but slightly decreased at 72 day fermentation. It is presumed that the characteristic flavor of fermented small shrimp might be attributed to the relatively higher content of hypoxanthine. In the free amino acid composition of fresh small shrimp abundant amino acids were proline, arginine, alanine, glycine, lysine, glutamic acid, leucine, valine and threonine in order. Such amino acids like serine, methionine, isoleucine, phenylalanine, aspartic acid, tyrosine and histidine were poor. In small shrimp extract, proline, arginine, alanine, glycine, lysine and glutamic acid were dominant holding $18.5\%,\;14.6\%,\;10.8\%,\;8.7\%,\;8.1\%\;and\;7.7\%$ of total free amino acids respectively. The total free amino acid nitrogen in fresh small shrimp was $63.9\%$ of its extract nitrogen. The change of free amino acid composition in the extract of small shrimp during fermentation was not observed. Lysine, alanine glutamic acid, proline, glycine and leucine were abundant in both fresh sample and fermented products. The increase of total free amino acids during 72 day fermentation reached approximately more than 2 times as compared with that of fresh sample and then decreased slowly. Fermented small shrimp with $40\%$ of salt was too salty to be commercial quality as the results of organoleptic test showed. It is found that 72 day fermentation with $20\%\;and\;30\%$ of salt gave the most favorable flavor. It is convinced that the characteristic flavor of fermented small shrimp was also attributed to such amino acids as lysine, proline, alanine, glycine and serine known as sweet compounds, as glutamic acid with meaty taste, and as leucine known as bitter taste. The amount of betaine increased during fermentation and reached the maximum at 72 day fermentation and then decreased slowly TMA increased while TMAO decreased during fermentation. The amount of TMAO nitrogen in fermented small shrimp was $200mg\%$ on moisture and salt free base. Betaine and TMAO known as sweet compounds were abundant in fermented small shrimp. It is supposed that these compounds could also play a role as important taste compounds of fermented small shrimp. At the initial stage of fermentation, Achromobacter, Pseudomonas, Micrococcus denitrificans which belong to marine bacteria were isolated. After 40 day fermentation, they disappeared rapidly while Halabacterium, Pediococcus, Sarcian, Micrococcus morrhuae and the yeasts such as Saccharomyces sp. and Torulopsis sp. dominated. It is concluded that the most important taste compounds of fermented small shrimp were amino acids such as lysine, proline, alanine, glycine, serine, glutamic acid, and leucine, betaine, TMAO and hypoxanthine.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.8
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• pp.1164-1172
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• 2011

Two experiments were conducted to evaluate the efficacy of Trichoderma reesei derived phytase for pigs fed diets with fixed calcium to total phosphorus ratios (1.5:1). In Exp. 1, 280 weaned pigs (initial BW of $10.32{\pm}1.94$ kg) were allocated to one of five dietary treatments on the basis of weight and gender in a randomized complete block design. Treatments were the low phosphorus (0.6% Ca, 0.4% total P and 0.23% available P) diets supplemented with 0, 250, 1,000, or 2,000 FTU phytase/kg of diet and a positive control diet (PC; 0.85% Ca, 0.58% total P and 0.37% available P). The treatments were applied to seven pens with eight pigs per pen, half male and half female. In Exp. 2, six barrows fitted with ileal T-cannula (initial BW = $35.1{\pm}1.6$ kg) were assigned to three dietary treatments with a double $3{\times}3$ Latin square design. The dietary treatments were the low-phosphorus diet (0.53% Ca, 0.34% total P and 0.14% available P), the low phosphorus diet plus 1,000 FTU phytase/kg and a positive control diet (0.77% Ca, 0.50% total P and 0.30% available P). In Exp. 1, there were linear increases (p<0.01) in weight gain, phosphorus absorption, bone strength, calcium and phosphorus content of fat-free dried bone and plasma phosphorus concentrations with increasing dose rate of phytase. The performance of pigs fed the diets with 250, 1,000, or 2,000 FTU of phytase/kg did not differ from pigs fed the PC diet. Pigs fed diets with 1,000 or 2,000 FTU of phytase/kg did not differ from pigs fed the PC diet in bone characteristics. The apparent digestibility of dry matter, crude protein, ash and energy was not affected by dietary treatment. However, pigs fed the PC diet excreted more fecal phosphorus (g/d, p<0.01) and fecal phosphorus per BW gain (g/kg) than pigs fed the diets with phytase. Phytase linearly decreased (p<0.01) fecal phosphorus excreted per BW gain (g/kg), plasma calcium concentration as well as plasma and bone alkaline phosphatase activity. In Exp. 2, phytase supplementation in the low-P diet increased (p<0.05) the apparent ileal digestibility (AID) of Ca, P, leucine, lysine, phenylalanine, alanine and cysteine, tended to AID of crude protein, isoleucine, threonine, asparagine and serine. In conclusion, the novel phytase originated from Trichoderma reesei is effective in releasing Ca, P, and amino acids from corn soy based diet for pigs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.235-240
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• 1979

A study on the amino acid composition of raw frozen krill, and krill solubles manufactured in forms of paste and powder has been carried out. The raw frozen krill was thawed, chopped, mixed and homogenized with same amount of water. The mixture was autolyzed or hydrolyzed by tile addition of $0.2\%$ pronase-p, a commercial proteolytic enzyme, to the weight of the raw frozen krill at $45^{\circ}C$ for 4 hours. After a thermal inactivation of enzymes at $95^{\circ}C$ for 15 minutes, the autolysate and the hydrolysate were centrifuged and filtered through gauzes, respectively, and then tile lipid layer in the supernatant was removed, The autolysate and the hydrolysate were finally concentrated under reduced atmospheric pressure in a rotary vacuum evaporator at $45^{\circ}C$ for 1 hour to produce the krill solubles in form of paste. The powdered krill solubles were prepared by the addition of $5\%$ starch to the autolysate and hydrolysate and by means of concentration in the rotary vacuum evaporator at $45^{\circ}C$ for 30 minutes and a forced air drying at $58^{\circ}C$ for 3 hours with a air velocity of 3m/sec. Among the amino acids in raw frozen krill, glutamic acid, lysine, and aspartic acid showed high values in quantity and then followed leucine, alanine, arginine, glycine and proline. The qnantity of histidine was very small and that of cystine was only in trace. The krill solubles in forms of paste and powder prepared by autolysis and hydrolysis with pronase-p revealed almost the same patterns in amino acid composition as in raw frozen krill. In case of free amino acids, a large quantity of it in raw frozen krill consisted of lysine, arginine, proline, alanine and leucine. The quantities of cystine, histidine and glutamic acid were, in contrast, very small. In the soluble krill paste prepared by autolysis, lysine, leucine, threonine and alanine existed in large quantities among the free amino acids and cystine, aspartic acid and histidine existed in small quantities. The contents of almost all of the free amino acids ill soluble krill paste perpared by hydrolysis with pronase-p were increased slightly as compared with those in soluble krill paste prepared by autolysis. In this product, the contents of cystine, histidine and serine were very low and lysine, leucine, arginine and proline were the dominant group in quantities among the free amino acids. The krill solubles in forms of paste and powder were not inferior to whole egg in the view point of its essential amino acid composition.