• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.994-1000
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• 1994

Hot water extract from mugwort (Artemisia asiatica nakai) leaves and tea inhibited the growth of Bacillus subtilis by adding to the nutrient broth 1.0% and 0.5% concentration, respectively. Among the important compounds that contributing mugwort like flavor to the mugwort leaves and tea were considered, authenic compound of thujone, caryophyllene and farnesol showed bactericidal effect for Escherichia coli, Enterobacter aerogenes, Vibrio paraheaemolyticus, Psudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus when teste by paper disc method ( 8 mm diameter). The mixture of caryophyllene and farnesol was more bactericidal effect for various bacteria than the mixture of thujone, caryophyllene and farnesol was more bactericidal effect for various bacteria that the mixture of thujone, caryophyllene and farnesol or each compounds . Especially, the mixture of caryophyllene and farnesol showed strong bactericidal effect (diameter of inhibition zone>40mm) for Vibrio parahaemolyticus , Enterobacter aerogenes and BAcillus subtilis.

• Journal of Microbiology and Biotechnology
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• v.1 no.3
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• pp.202-206
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• 1991

To produce acetoin as a precursor of the tetramethylpyrazine flavor compound from citrate by Lactococcus lactis ssp. lactis biovar. diacetilactis FC1, fermentation factors such as inital pH of culture media, temperature, concentration of Na-citrate, thiamin-HC1 and sugars were examined. The best acetoin production was achieved with initial pH in the culture media of 5.5, fermentation temperature of $34^{\circ}C$, Na-citrate concentration of 3%, addition of thiamin-HC1 at 2 mg/l and galactose as a carbon source. When fermentation was carried out under the optimum conditions, the exhaustion of Na-citrate and the production of acetoin took simultaneously and acetoin reached the maximum content, 80 mmole/l after 20 hours.

• Journal of Microbiology and Biotechnology
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• v.1 no.4
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• pp.285-287
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• 1991

To produce the tetramethylpyrazine (TMP) flavor compound, Lactococcuss lactis subsp. lactis biovar. diacetilactis (L. diacetilactis) FC1 was cultivated in the TMP medium containing 3% (w/v) of Na-citrate and 6% (w/v) arginine-HC1 as substrates of acetoin and $NH_3$, respectively, which are the two precursors of the TMP. After 19-day fermentation at $34^{\circ}C$, 0.57 g/l or 4.19 mmole/l of the TMP was produced. This was the first result showing that the TMP could be produced by L. diacetilactis.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.316-323
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• 1996

Flavor components in mash of Takju prepared by different raw materials such as nonglutinous rice, glutinous rice, barley and wheat flour were detected by GC and GC-MS method using non-polar column. Seven alcohols, 15 esters, 10 organic acids, 1 aldehyde, 4 benzenes, 3 phenols, 8 alkans, 2 ketones and 5 others were found in takju after 16 day of fermentation. takju by wheat flour had the most various components of volatile flavor. Treatment with addition starter had less flavor component than that without addition starter in takju by nonglutinous rice. Nine kinds of flavor components including acetic acid ethyl ester, 3- methyl-1-butanol, acetic acid, ethyl benzene, acetic acid 3-methyl butyl ester, 2-phenylethanol, 2,6-di-tert-butyl-4-methyl phenol. plumbagic acid and 1,2-benzenedicarboxylic acid dibutyl ester were commonly detected in all the treatments. Especially, 2,4,0-trimethyl-1,3-benzenediamine was isolated in takju that was made of nonglutinous rice without addition starter. Diethyl sulfide, 4-methoxy benzaldehyde, docosane and 2-methyl propyl octadecanoic acid were isolated from takju by nonglutinous rice with addition starter. Propionic acid ethyl ester, acetic acid butyl ester, 2-methyl butane and 3-methyl pentane were isolated from takju glutinous rice. 2-Hydroxy-4-methyl pentanoic acid and 2-methyl tridecane were isolated from akju by barley 3-(Methylthio)-1-propanol. hexanoic acid ethyl ester, butanoic acid monomethyl ester, tridecanoic acid, ethyl tetramethyl cyclopentadiene and 1,5-diaza-2,9-diketocyclotetradecane were isolated from takju by wheat flour. Major volatile flavor components were acetic acid ethyl ester, 3-methyl-1-butanol, acetic acid and 2-phenylethanol.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.30-36
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• 1996

This study was conducted to investigate the changes in chemical, microbial, sensory characteristics and volatile flavor components of wooung(burdock, Arctium lappa, L) kimchi during fermentation at 15$^{\circ}C$, Three types(A, B, C) of wooung kimchi were prepared. Sample A was prepared with basic ingredients, in the other hand, sample B was prepared with all sorts of ingredients. These samples were mixed after salting the sliced burdock with 4% brine for 30min. Sample C was prepared mixing with all sorts of ingredients after blanching the sliced burdock with 2% vinegar solution. pH decreased slowly until 3 day, and then decreased rapidly for 4~7 days in all samples. Total acidity increased gradually in all samples. The changes of pH and total acidity were the sample C and were the greatest in sample B. The reducing sugar contents decreased slowly until 7 day, and decreased rapidly for 8~14 days in sample A and B, and at 10 day in sample C, respectively. The numbers of lactic acid bacteria and total bacteria of sample B were much greater than those of other sample. In sensory evaluation, sample B exhibited the best scores and sample C showed the worst scores in all characteristics. The major volatile components in wooung kimchi were identified as ethanol, hexanal, 2-hexenal, disulfide dl- 2-prophenyl, zingiberene and $\beta$-sesquiphellandrene. The relative amounts of hexanal, 1-hexanol and ethanol were decreased, while the relative amounts of acetic acid ethyl ester, 3-htdroxy-2-butanone and acetis acid were increased gradually during fermentation.

• Applied Biological Chemistry
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• v.39 no.4
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• pp.249-254
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• 1996

The volatile flavor components in mash of nonglutinous rice Takju brewed with or without addition of the starter were determined by GC and GC-MS using polar column. Various kinds of volatile components including alcohols(10), esters(9), organic acids(2) and aldehydes(7) were found in mash of nonglutinous rice Takjus. At the beginning stage of fermentation, 3 to 7 volatile flavor components were detected. The number of volatile flavor components were increased to 26 of to 28 after 16 days fermentation. Early in the brewing, just 3 kinds of flavor components including ethyl acetate, ${\beta}-phenylethyl$ acetate and acetic acid were detected in mash of nonglutinous rice Takju without the addition of the starter, when starter is added additional compounds of alcohol including ethanol were detected, which is suggested to be the effect of flavors originated from the starter. The common flavor compounds through the entire process of fermentation in mash of nonglutinous rice Takju were ethyl acetate, ${\beta}-phenylethyl$ acetate and acetic acid. The relative amount(peak area %) of flavor components were changed with the fermentation period, but the major volatile flavor components were ethyl alcohol, iso-amyl alcohol, hexenyl alcohol, ethyl acetate, ${\beta}-phenylethyl$ acetate and ${\beta}-phenylethyl$ alcohol. The relative amount(peak area %) of ethyl alcohol was the highest in mash of nonglutinous rice Takju with addition of starter. When the starter was not added in the mash of nonglutinous rice Takju, any alcoholic components were not detected in the early stage of fermentation. But the percent of peak area hexenyl alcohol was the highest after 16 days fermentation. Especially few sorts of ester were detected in mash of nonglutious rice Takju without addition of starter by 3 days fermentation.

• Journal of Microbiology and Biotechnology
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• v.34 no.3
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• pp.622-633
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• 2024

For quality standardization, the application of functional lactic acid bacteria (LAB) as starter cultures for food fermentation is a well-known method in the fermented food industry. This study assessed the effect of adding a non-thermally microbial inactivated starter culture to kimchi, a traditional Korean food, in standardizing its quality. In this study, pretreatment based on sterilization processes, namely, slightly acidic electrolyzed water (SAEW) disinfection and ultraviolet C light-emitting diode (UVC-LED) of raw and subsidiary kimchi materials were used to reduce the initial microorganisms in them, thereby increasing the efficiency and value of the kimchi LAB starter during fermentation. Pretreatment sterilization effectively suppressed microorganisms that threatened the sanitary value and quality of kimchi. In addition, pretreatment based on sterilization effectively reduced the number of initial microbial colonies in kimchi, creating an environment in which kimchi LAB starters could settle or dominate, compared to non-sterilized kimchi. These differences in the initial microbial composition following the sterilization process and the addition of kimchi LAB starters led to differences in the metabolites that positively affect the taste and flavor of kimchi. The combined processing technology used in our study, that is, pre-sterilization and LAB addition, may be a powerful approach for kimchi quality standardization.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.2
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• pp.104-113
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• 2012

Crab-like flavorants (CFs) were made from snow crab cooker effluent (SCCE) using response surface methodology (RSM) and reaction flavoring technology (RFT). Type A CF was made from SCCE via RSM, RFT, adding starch syrup, centrifugation, and microfiltration. Type B was made from type A by adding the food additives dimethyl sulfide, ethyl valerate and fish sauce. The stability of the CFs was evaluated in terms of the color values, sensory evaluation, and flavor profiles after storage for 90 days at three different temperatures: 10, 20, and $30^{\circ}C$. The compounds, ethanol and 3-methyl-1-butanol, were considered key components of off-flavor and a decrease in dimethyl-2-vinylpyrazine affected the occurrence of off-flavor. It may be a microbial metabolite arising from contamination and lab-scale micro-filtration. At the lowest temperature ($10^{\circ}C$), the decrease in volatile compounds, such as pyrazines, was not as dramatic as at $20^{\circ}C$ and $30^{\circ}C$ and alcohol formation was prevented or delayed. Therefore, it is necessary to store CFs at < $10^{\circ}C$ with suitable sterilization to preserve volatile flavor compounds and prevent off-flavor from occurring.

• Food Science of Animal Resources
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• v.36 no.4
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• pp.558-565
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• 2016

The aim of this study was to investigate the influence of proteolytic pork hydrolysate (PPH) on yoghurt production by Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Fresh lean pork was cut into pieces and mixed with deionized water and dealt with protease, then the resulting PPH was added to milk to investigate the effects of PPH on yoghurt production. The fermentation time, the viable cell counts, the flavor, free amino acids compounds, and sensory evaluation of yoghurt were evaluated. These results showed that PPH significantly stimulated the growth and acidification of the both bacterial strains. When the content of PPH reached 5% (w/w), the increased acidifying rate occurred, which the fermentation time was one hour less than that of the control, a time saving of up to 20% compared with the control. The viable cell counts, the total free amino acids, and the scores of taste, flavor and overall acceptability in PPH-supplemented yoghurt were higher than the control. Furthermore, the contents of some characteristic flavor compounds including acids, alcohols, aldehydes, ketones and esters were richer than the control. We concluded that the constituents of PPH such as small peptide, vitamins, and minerals together to play the stimulatory roles and result in beneficial effect for the yoghurt starter cultures growth.

• Journal of Microbiology and Biotechnology
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• v.1 no.4
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• pp.281-284
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• 1991

To investigate the optimum conditions for the production of ammonia as a precursor of tetramethylpyrazine flavor compound from arginine by Lactococcus lactis ssp. lactis biovar. diacetilactis FC1, fermentation factors such as initial pH of culture media, fermentation temperature, concentration of arginine-HC1, and sugars were examined. The optimum conditions were initial pH 5.5 of the culture media, fermentation temperature of $34^{\circ}C$, 6% (w/v) of arginine-HC1, and 1% (w/v) of galactose as a carbon source. Under the optimum fermentation conditions, 40 mmole/l of ammonia was produced after 40 h.