• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.1
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• pp.16-23
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• 1998

Effect of Fermentation temperature on the changes of chemical components in Kakudgi during fermentation was investigated by measuring free sugar, organic acid and volatile compounds up to 57 days at several temperatures. The mannitol was increased in palatable period in contrast with those of other free sugars. The higher the initial fermentation temperature was and the longer the initial fermentation time at 2$0^{\circ}C$ was, the faster the second increasing period was and the less the initial contents was. Lactic acid was increased 6~31 times from a little amount at the initial period. The higher the initial fermentation temperature was and the more the increasing content was. But malic acid which was abundant(55.1% of total nonvolatile organic acid) in the initial fermentation period was remarkably decreased in the palatable period. The change of the sulfides among the volatile compounds was remarkable. Methyl allyl sulfide which was a little in the initial fermentation period was remarkably increased in the final fermentation period, and the correlation coefficients between the content of methyl allyl sulfide and aroma in sensory evaluation were high. It could be suggested that the fermentation temperature should be set to 4$^{\circ}C$ after fermentating at 2$0^{\circ}C$ for 36 hours in the view point of keeping the Kakdugi taste and quality well because of high content of free sugar and nonvolatile organic acids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.10 no.1
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• pp.1-16
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• 1981

Fermented trepang entrails, Stichopus Japonicus, is widely used and occupied an important position in foods of this country. But little study on its taste compounds has been reported. This study was attempted to establish the basic data for evaluating taste compounds of fermented trepang entrails. Changes of free amino acids, free sugars, nucleotides and their related compounds as taste compounds during the fermentation of trepang entrails were analyzed by amino acid autoanalyzer and high speed liquid chromatography. Glutamic acid, alanine, glycine and proline were dominant amino acid in the fresh extracts, having 32.3%, 16.4%, 12.0% and 10.5% of the total free amino acid content, respectively. The content of leucine, valine, phenylalanine, isoleucine, methionine and tyrosine were low. The free amino acid were not changed in composition but changed in amounts during the fermentation of trepang entrails. Glutamic acid, alanine, glycine, proline, lysine, arginine and leucine were abundant in both fresh sample and fermented products. Free sugars in fermented trepang entrails, the results showed that galactose(933.7-988.0 mg%) was dominant and the content of arabinose, xylose were 78.7, 55.2-771mg% on moisture and salt free base respectively but glucose was detected in trace amount. Nucleotides and their related compounds were increased during the fermentation and hypoxanthine(47.1-$62.5{\mu}mole/g$, on moisture and salt free base) were dominant, IMP was abundant in fermented trepang entrails. TMA was increased while TMAO was decreased during the fermentation. The content of TMAO nitrogen in fermented trepang entrails was 30.0mg% on moisture and salt free base. The content of betine was increased during the fermentation and was ranged from 734.2 to 934.2mg% on moisture and salt free base. It is believed that such amino acids as glutamic acid, alanine, glycine, lysine, proline, arginine, leucine, such free sugars as galactose, arabinose, xylose, glucose, such nucleotides and their related compounds as IMP, hypoxanthine play an important role as taste compounds in fermented trepang entrails.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.2
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• pp.237-247
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• 2012

This study assessed the removal characteristics of taste and odor causing compounds (2-methylisoborneol and geosmin) and organic matters, using a pilot-scale ozone/granular activated carbon ($O_{3}$/GAC) process treating surface water of Pal-dang reservoir in the Han river over a 3-month period. Experiments were conducted to verify the removal efficiency of $O_{3}$/GAC process which has two different empty bed contact time (EBCT) ($O_{3}$/GAC column 1 : 10 min and 2 : 15.1 min) with 10.86 min contact time of ozonation at 1.0 mg/L $O_{3}$. Spiking test using geosmin and 2-MIB was also conducted systematically to mimic the conditions when the algae appears, specifically at the levels similar to the concentrations experienced (geosmin: 250 ng/L) in the winter of 2011. In single ozonation process, organic materials, disinfection by-products (DBPs) and their precursors were disassembled but not removed completely. Meanwhile, it was verified that organic matters, taste and odor causing compounds, and DBPs were well removed when sequentially passing through the GAC process. The pilot results also showed that GAC column with larger EBCT achieved higher removal efficiency. Specifically, in spiking tests, single $O_{3}$ process showed approximately 89% removal efficiency of geosmin and 2-MIB. $O_{3}$/GAC combined process demonstrated excellent removal of geosmin and 2-MIB, which are higher than 95%.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.7
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• pp.1026-1030
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• 2011

An experiment was conducted to determine the effects of caponization on the muscle composition, ATP-related compounds, the shear values, the taste panel scores and the muscle fiber areas of Taiwan country chicken cockerels. At 10 wks of age, cockerels were divided into two groups: caponized and untreated. Birds were fed grower and finisher diets ad libitum in an eighteen-week experimental period. Results showed that capons contained significantly greater muscle fat content, less breast and thigh muscle moisture content, shear value and muscle fiber area (p<0.05) than those of intact birds. However, neither treatment groups differed significantly (p>0.05) in breast and thigh muscle protein content. Compared with the intact birds, the capons contained significantly (p<0.05) less muscle ash content in the breasts, but did not differ significantly (p>0.05) in thigh muscle ash content. The breast muscle IMP and ATP+ADP+AMP+IMP contents in the intact birds were significantly (p<0.05) higher than those in the capons. The intact birds had significantly (p<0.05) higher ATP and AMP contents than did the capons as well as significantly (p<0.05) less ADP and inosine (HxR) contents in the thigh and breast muscles. The Hypoxanthine (Hx) content of the thighs in the intact birds was significantly (p<0.05) higher than that in the capons; however, there was an adverse effect on the breast muscle Hx content. The breast muscle K value in the intact birds was significantly (p<0.05) lower than that in the capons. The capons produced significantly (p<0.05) higher taste panel scores than did the intact birds for both flavor and juiciness of thigh muscle as well as for flavor and tenderness of breast muscle.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.1
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• pp.98-104
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• 1995

Five bitter taste compounds (OY-22, OY-23, OY-24, OY-25 and OY-26) were firstly isolated from cultured oyster (Crassostrea gigas) at Gamak Bay, Sourthern coast of Korea, between November, 1989 and January, 1990, and smoked-canned oyster, which were produced by the same oysters. They were presumed as cyclic peptides composed with 6 or 7 amino acids, including sulfur on the basis of NMR and MS spectra. Val and Leu in OY-24, leu and lie in OY-25 and tow leucines in OY-26 were detected from those each compounds, seperately, by the amino acid analysis. Another amino acids were thought as non-constitutional amino acids. They showed non-toxic to mice $(100{\mu}g/20g\;mice i.p.)$ and non actibacterial artivities to Asp. niger and B. subtilis $(10{\mu}g/disk)$. The chemical structures and other biological activities of them are now in studying.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1201-1207
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• 1999

To utilize the leaves of broccoli, the shape of which was similar with that of kale leaves, as a vegetable juice, the extracts from two types of vegetable leaves were subjected to the analyses of proximate com ponents, volatile sulfur compounds, vitamin C and minerals. The sensory evaluation of the juices, prepared from kale and broccoli leaves, were performed by duo trio test and scoring test. Among eight varieties of broccoli, four varieties('Pilgrim', 'Greenbelt', 'Salinas' and 'Shasta')were not significantly different from kale(p<0.05), based on the duo trio sensory test. Sulfur and nitrogen compounds present in the dichloromethane extracts of kale and broccoli leaves 'Pilgrim' were identified as 3 butenyl, allyl, butyl and 4 methylsulfinylbutyl isothiocyanate(sulforaphane), 4,5 epithiovalero, 4,5 epithio 3 hydroxyvalero, benzenepropane, 3 hydroxy 4 propene, 4 methylthio butane, 3 hydroxy 3 phenylpropane, 5 methy lsulfinylpentane, 4 methoxyphenyl 3 hydroxypropane nitrile and dimethyl trisulfide by GC/MSD analysis. Proximate components were observed to be relatively similar between kale and broccoli leaves. Vitamin C and sugar content were higher in broccoli leaves(125∼180mg% and 8∼12°Brix) than in kale(101mg% and 7oBrix). In mineral analysis by AA and ICP Mass, 'Pilgrim' showed a higher content of K, Fe, Mn, Zn and Se. In separate experiment, sensory scores of bitter taste and astringent taste were lower and scores of over all taste and over all acceptability, higher in broccoli('1243') juice than those in kale juice.

• Preventive Nutrition and Food Science
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• v.7 no.4
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• pp.427-431
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• 2002

Alkali treatment following acidic hydrolysis (ATAH) is a commonly used practice for reducing the levels of monochloropropanediol in commercial Korean soy sauce. This study investigated the chemical compounds produced in commercial Korean soy sauce made by ATAB. The levels of amino-N, total acidity, pH, salinity and Brix of the soy sauce were 6.66%, 2.52%, 19.81%, 4.57 and 35.01, respectively. The major fatty acids were C18:2n-6, C16:0, Cl8:ln-9 and C18:3n-6. The concentration of polyunsaturated fatty acids were especially high, with of C18:2n-6 (49.8%) being the highest followed by C18:3n-6 (3.8%) and C18:3n-3 (2.4%) in that order. Among the non-volatile organic acids, the concentration of levulinic acid (1,206.28 mg/100 g) was the highest, while the taste value of citric acid was the highest. Among the ATP related compounds, IMP concentration (31.19 mg/100 g) was highest followed by AMP, hypoxanthine and GMP in that order. The concentrations of free and total amino acids in soy sauce were 6,136.94 mg/100 g and 8,702.76 mg/100 g, respectively. On the other hand, the taste value of glutamic acid, a major amino acid flavor determinant in soy sauce, was highest of all the amino acids, which is desirable since most free amino acids such as methionine, histidine and phenylalanine have a bitter taste that detracts from the flavor of soy sauce.

• Journal of Korean Society on Water Environment
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• v.24 no.5
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• pp.598-602
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• 2008

The Daecheong Reservoir is the largest multi-purpose reservoir in the Keum River basin. This water supply is subject to some of the most serious taste and odor (T&O) problems in the region. The intensity of T&O events increased due to eutrophication during the 1990s. In this study, the temporal occurrence of T&O in raw water from the main Daecheong Reservoir and its regulating reservoir was compared using both an instrumental method (CLSA+GC/MS) and threshold odor number (TON) test from April to December 2006. In addition, biofilms on the submerged macrophytes and rocks were analyzed for two typical T&O causing compounds, Geosmin and 2-MIB. The maximum concentration of Geosmin in the main reservoir was almost two times higher than that in the regulating reservoir. Interestingly, 2-MIB was only detected in water samples from the main reservoir. In the case of T&O causing compounds present in the biofilm on the submerged macrophytes and rocks, the regulating reservoir had lower concentrations compared to those of the main reservoir. It was found that both Geosmin and 2-MIB were detected from the biofilms much earlier than from the water samples. This result suggests that the occurrence of T&O compounds in the biofilms could be used as an early warning indicator of an imminent T&O outbreak in the water body.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.298-305
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• 2016

Prior research has attempted to develop a method for fermentation of onion vinegar to satisfy customer quality standard. Onion wine (OW) and onion vinegar (OV) were produced by alcoholic and acetic fermentation of onion extracts (OE) using Saccharomyces cerevisiae and Acetobacter pasteurianus, and their taste compounds (non-volatile organic acids, non-protein N compounds, and free sugars) were determined. Main components of non-volatile organic acids were malic acid (50.1%) and citric acid (26.9%) in OE, whereas malic acid (28.1%), acetic acid (20.8%), lactic acid (20.1%), citric acid (13.3%), and succinic acid (12.0%) were detected in OW. Total concentrations of non-volatile organic acids in OV were 4,612.0 mg/100 g, which was 3.9 and 2.3 times higher than those of OE and OW, respectively. Non-volatile organic acids except malonic acid and acetic acid were reduced during acetic fermentation. Non-protein N compounds increased 4.23-fold ($41,526.8{\mu}g/100g$) during alcohol fermentation, and urea content was the highest of non-protein N compounds at $33,816{\mu}g/100g$. The reduced values in OV might be used as a nutritious element of Acetobacter pasteurianus. Free sugars (glucose, fructose, and sucrose) were detected in OE, whereas only fructose was absent in OW and OV.

• Korean Journal of Food Science and Technology
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• v.27 no.2
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• pp.241-245
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• 1995

Focusing on quality problems of delayed chilling porcine muscle, the effects of delayed chilling and aging on the contents of ATP-related compounds and taste of pork were investigated. Twelve Landrace pigs were employed and bisected: left sides were delay-chilled(DC) at room temperature($20^{\circ}C$) for 3 hrs, whereas right sides were conventionally chilled(CC). ATP-related compounds tested were adenosine triphosphate(ATP) and its derivatives in pork muscle, inosine monophosphate(IMP), guanosine monophosphate(GMP) and L-glutamate in cooked broth. DC sides showed more rapid pH decline and degradation of nucleotides than did CC sides. The levels of ATP and adenosine monophosphate(AMP) were not changed significantly. However, adenosine diphosphate(ADP) and IMP showed the highest levels at the 1st and 5th day, respectively. Hypoxanthine(Hx) was gradually increased(p<0.05) during aging. During aging, the IMP contents cooked broth tended to decrease, while the GMP and L-glutamate contents increase. As a result of these, the taste score got better and finally the results of sensory evaluation became increased(p<0.05). However, compared to CC sides, DC sides did not seem to lower taste of pork.