• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.373-377
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• 2001

Egg white mix (EWM) added with different ratios of cream $(10{\sim}15%,v/v)$ was fermented with Lactobacillus acidophilus (KCTC 2182) and changes of volatile aroma compounds during fermentation for 21 h were investigated. The amount of volatile aroma compounds between pre-fermented EWM, 15 h-fermented EWM, soft ice cream prepared from fermented EWM, and hard ice cream prepared from soft ice cream was compared. The results were as follows: (1) The amount of ethanol increased gradually until 9 h and increased rapidly to maximum value at 12 h and then decreased rapidly. The amount of acetone at 12 h was slightly higher, but it was not changed markedly during fermentation. Diacetyl was detected at 3 h and increased gradually to maximum value until 15 h and then decreased slightly. The amount of butanol was not changed markedly during fermentation. Acetoin was detected at 3 h and increased rapidly until 15 h and then increased gradually. (2) The amount of acetone, ethanol, diacetyl and butanol of pre-fermented sample, 15 h-fermented sample, soft ice cream and hard ice cream increased in proportion to the amount of cream added to EWM. However, the amount of butanol was relatively constant regardless of added cream ratio. The amount of volatile aroma compounds of soft ice cream was higher than that of other samlples, while that of pre-fermented sample was lower than that of other samples. Diacetyl and acetoin were not detected in pre-fermented sample.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.7-14
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• 2003

Physico-chemical and sensory characteristics of six dongchimi cultivars were evaluated. Moisture and sugar contents were 94.2% and $4.30^{\circ}Brix$ for three spring radish cultivars, while 92.9% and $7.30^{\circ}Brix$ for three autumn ones. pH $(5.7{\sim}6.1)$ and acidity $(0.09{\sim}0.12%)$ did not show significant differences among cultivars. pH decreased steadily up to 21 days to reach optimum pH of 4.0. The maximum number of total lactic acid bacteria, $10^8{\sim}10^9\;CFU/mL$, was reached at pH 4.0. The final acidity of spring radishes was lower than that of autumn ones, and was proportional to the sugar content of the radishes. The firmness of spring radish decreased rapidly compared to the autumn ones. Cheongbok was found suitable for dongchimi, because its firmness level was maintained around $165.0{\times}10^3\;N/m^2$ at 35 days. Sensory evaluation revealed 96371 among spring radishes and cheongbok among autumn radishes scored high in firmness, chewiness, flavor, and overall acceptance. These results suggest that autumn radishes are suitable for dongchimi fermentation with cheongbok being the best among the cultivars.

• KSBB Journal
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• v.31 no.1
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• pp.27-32
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• 2016

Several CoA transferases from Clostridium beijerinckii, C. perfringens and Klebsiella pneumoniae were examined for biosynthesis of lactate-containing polyhydroxyalkanoates (PHAs) in recombinant Escherichia coli XL1-Blue strain. The CB3819 gene and the CB4543 gene from C. beijerinckii, the pct gene from C. perfringens and the pct gene from K. pneumoniae, which encodes putative CoA transferase gene, respectively, was co-expressed with the Pseudomonas sp. MBEL 6-19 phaC1437 gene encoding engineered Pseudomonas sp. MBEL 6-19 PHA synthase 1 ($PhaC1_{Ps6-19}$) to examine its activity for the construction of key metabolic pathway to produce poly(3-hydroxybutyrate-co-lactate) [P(3HB-co-LA)]. The recombinant E. coli XL1-Blue expressing the phaC1437 gene and CB3819 gene synthesized poly(3-hydroxybutyrate) [P(3HB)] homopolymer to the P(3HB) content of 60.5 wt% when it was cultured in a chemically defined medium containing 20 g/L of glucose and 2 g/L of sodium 3-hydroxybutyrate. Expression of the phaC1437 gene and CB4543 gene in recombinant E. coli XL1-Blue also produced P(3HB) homopolymer to the P(3HB) content of 51.2 wt% in the same culture condition. Expression of the phaC1437 gene and the K. pneumoniae pct gene in recombinant E. coli XL1-Blue could not result in the production of PHAs in the same culture condition. However, the recombinant E. coli XL1-Blue expressing the phaC1437 gene and the C. perfringens gene could produce poly(3-hydroxybutyrate-co-lactate [P(86.4mol%3HB-co-13.7 mol%LA) up to the PHA content of 10.6 wt% in the same culture condition. Newly examined CoA transfereases in this study may be useful for the construction of engineered E. coli strains to produce PHA containing novel monomer such lactate.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.666-672
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• 2002

Changes in chemical characteristic, microflora, and sensory evaluation of fish sauce extracted at an interval of one week from fermented solution were investigated. pH was reduced from 6.0 to 4.5, and trimethylamine oxide from 132.5 to 87.2 mg/100g during fermenting periods. Trimethylamine increased from 5.6 to 50.2 mg/100g, and volatile basic nitrogen from 48.3 to 232.5 mg/100g. Bacterial flora isolated from the fish sauce were 70% Lactobacillus sp. and 13% Bacillus sp. Among the free amino acids, alanine, glutamic acid, valine, and methionine contents constitute 40% of the total free amino acids. Major non-volatile organic acid of the fish sauce was lactic acid (76%). Sensory evaluation results of the fish sauce were higher than the traditional soybean sauce after 28 days of fermentation.

• Korean Journal of Food Science and Technology
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• v.50 no.6
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• pp.601-607
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• 2018

We examined the physicochemical characteristics of radish kimchi supplemented with either 10% boneless or boned sliced gizzard shad (BLGS and BGS, respectively) and compared them to those of untreated kimchi during an eight-week fermentation period. BLGS- and BGS-containing kimchi showed higher acidity, amino nitrogen, and Lactobacillus levels than control kimchi. Furthermore, BGS-containing kimchi showed higher acidity, amino nitrogen, and Lactobacillus levels, and lower reducing sugar contents than BLGS at the optimum- and over-ripened stage. Higher amino nitrogen serves as a good medium for microorganism growth, which produce organic acids, consequently decreasing the reducing sugar, pH levels and increasing the acidity. The preference test showed that the control kimchi was the most preferred at the unripened stage, while the BLGS- and BGS-supplemented kimchi samples in the ripened and over-ripened stages showed similar preferences. In conclusion, our results indicate that gizzard shad-supplemented kimchi shows positive health characteristics, such as low salinity, high amino nitrogen and Lactobacillus levels.

• The Korean Journal of Mycology
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• v.27 no.4 s.91
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• pp.256-273
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• 1999

Seventy two isolates of Cordyceps militaris collected from 11 sites in Korea, including two isolates from ATCC, were used to assess genetic variation within Cordyceps militaris. The anamorph stage and cultural characteristics of C. militaris were observed through microscope and investigated on PDA respectively. The anamorphs of C. militaris were identified to be Verticillium. Isolates of C. militaris showed different growth rates, morphology and color. Fifty six isolates of single ascospore and seventy two isolates of mass ascospore from C. militaris were analysed using by Random Amplified Polymorphic DNA (RAPD) for genetic relationship analysis. Fifty six single ascospore isolates fell into two groups by phenogram constructed from distance values using the UPGMA method in NTSYS-pc software: group A from artificial fruit body of C18 except for isolate 51; group B from artificial fruit body of C738. The average genetic distance value within group A is 0.150 and group B is 0.163. The average genetic distance value between the two groups is 0.221. The average genetic distance value within 56 single ascospores is 0.207 and 72 mass ascospores is 0.330. Genetic relationships were not found among 72 mass ascospore isolates obtained from eleven geographically distant populations.

• The Korean Journal of Food And Nutrition
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• v.18 no.4
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• pp.349-356
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• 2005

For the purpose of making a new type of functional drinkable yoghurt, skim milk containing $0.5\~2.0\%$(w/v) green tea powder was fermented by the mixed stains of Streptococcus thermophilus and Lactobacillus acidophilus. Quality characteristics of the drinkable yoghurts were evaluated in terms of quality-keeping properties(number of viable cells, pH, titratable acidity) and sensory properties. When the drinkable yoghurts added with $0.5\~2.0\%$ green tea powder were kept at $4^{\circ}C\;and\;20^{\circ}C$ for 20 days, the number of viable cell counts of the lactic acid bacteria($2.1\times10^8\~6.2\times10^8$ CFU/mL). pH($4.16\~4.22$) and titratable acidity($0.792\~0.881\%$) were not significantly changed for all drinkable yoghurts during the storage at $4^{\circ}C\;and\;20^{\circ}C$ days, but the number of viable cell counts($4.2\times10^3\~1.8\times10^5$ CFU/mL), pH($3.82\~3.92$) and titratable acidity($1.057\~1.174\%$) were markedly changed f3r the storage at $20^{\circ}C$ for 20 days. Therefore the keeping quality of the drinkable yoghurts with addition of green tea powder was relatively good at $4^{\circ}C$ for 20 days. The results of sensory evaluation of the drinkable yoghurts containing peen tea powder indicated that flavor, sweet taste, mouthfeel and aftertaste of the drinkable yoghurt with $0.5\%$ green tea powder showed higher preference than others. And the drinkable yoghurt containing $0.5\% green tea powder added $20\%$(v/v) oligosaccharide had the higher sensory scores in sweet taste, aftertaste and overall acceptability among the treatments.

• Journal of the Korean Society of Food Culture
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• v.18 no.6
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• pp.551-561
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• 2003

To determine the conditions of the fermentation and storage for Chonggak kimchi in kimchi refrigerator, prepared Chonggak kimchi took into kimchi refrigerators which were controlled at four different modes of the fermented temperature and time, and fermented and kept for 16 weeks. The pH in Chonggak kimchi fermented at $20^{\circ}C$ for 24 hours/stored at $-1^{\circ}C$ dropped greater than all of kimchi fermented at other combinations, and the changes of pH at any combinations were not greater than those in Baechu kimchi, because pH in Chonggak kimchi did not dropped below 4.5. Acidities in Chonggak kimchi were greatly increased at higher temperature. The acidity in Chonggak kimchi during the first week of fermentation was lower than that in Baechu kimchi and then it was rather higher because of the addition of waxy rice paste. In texture, puncture force of Chonggak kimchi was decreased slowly until 8 weeks of fermentation and then did not changed much and the highest values showed in Chonggak kimchi stored directly at $-1^{\circ}C$ without any fermentation. In sensory evaluation, the scores for the carbonated flavor and the sourness were the highest in Chonggak kimchi fermented at $20^{\circ}C$ for 24 hours/stored at $-1^{\circ}C$, but the lowest in Chonggak kimchi stored directly at $-1^{\circ}C$ without any fermentation because of some undesirable flavors. The lowest hardness showed in Chonggak kimchi fermented at highest temperature and the best hardness was in Chonggak kimchi fermented at $5^{\circ}C$ for 3 days or 6 days/stored at $-1^{\circ}C$. The appearance was the best in Chonggak kimchi fermented at $20^{\circ}C$ for 24 hours/stored at $-1^{\circ}C$ and the worst was in Chonggak kimchi stored directly at $-1^{\circ}C$ without any fermentation. The overall acceptability of Chonggak kimchi fermented at $20^{\circ}C$ for 24 hours/stored at $-1^{\circ}C$ was good after 4 weeks of fermentation, but in Chonggak kimchi fermented at $5^{\circ}C$ for 3 days or 6 days/stored at $-1^{\circ}C$ it was good after 6 weeks. Total microbial counts in most of Chonggak kimchi were reached to a maximum number within 7 days, and then decreased similarly at all modes. Leuconostoc spp. and Lactobacillus spp. increased to maximum number of $1.48{\times}10^9\;and\;5.62{\times}10^9$, respectively, in Chonggak kimchi fermented for 7 days. Yeast counts showed a increasing trend not depends on fermenting temperature and they were lower counts than those in Baechu kimchi. Waxy rice paste which added to Chonggak kimchi resulted in increasement of glucose as a carbon source and stimulated to reproduce the microbes in Chonggak kimchi.

• Food Science and Preservation
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• v.19 no.1
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• pp.131-137
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• 2012

This study was carried out to investigate the physiochemical and microbiological changes of dandelion during fermentation. Thirty and fifty percentage raw sugar groups (SFE30 and SFE50) were introduced into dandelions and fermented for 120 days at $15-20^{\circ}C$. This study was conducted to investigate the utilization of sucrose on lactic acid bacteria from dandelions and their effect on the pH, titratable acidity, microorganism and formation of organic acids in dandelions during fermentation. The number of lactic acid bacteria increased remarkably up to 15 days of fermentation and then decreased rapidly thereafter. The maximum number of lactic acid bacteria, 7.9 log CFU/mL was reached at pH 4.17 and the pH of dandelion showed a slight decrease during fermentation and decreased steadily up to 90 days to reach an optimum pH of 4.0. The titratable acidity of dandelions fermented increased during fermentation. The concentration of organic acid, amino acid and free sugar in SFE30 was higher than both SFE50 and DWE. The results of dandelions fermented were remarkably retarded in the 50% raw sugar group compared to the 30% raw sugar group.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.1
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• pp.57-62
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• 2015

"Nokyang" (Hordeum vulgare L.), a new whole-crop silage barley cultivar, was developed by the breeding team at the Department of Rice and Winter Cereal Crop, National Institute of Crop Science, RDA, Korea in 2012. It was derived from combining "Nagyoung" and breeding line "SB77368-B-145". Among the combinations made in 2001, a promising line, "SB01T2017", showed good characteristics in terms of potential forage yield in the yield trial at Iksan from 2007 to 2009. In 2009, the promising line was designated as "Iksan457" and placed in regional yield trials at six locations around Korea for three years from 2010 to 2012, and was released under the name of "Nokyang." It has the growth habit of a group III creeping plant type, with a light-green leaf and common spike. Its average heading and maturing dates were on May 6 and June 4, respectively, which were later than cultivar "Youngyang." "Nokyang" also showed strong winter hardiness, and a resistance to shattering and barley yellow mosaic virus (BaYMV) similar to those of the check cultivar. The best thing among the traits of one is a new good quality with the plant green at the latter growing period. The average forage dry matter (DM) yields in the regional yield trial were about 12.8 and 11.5 MT $ha^{-1}$ in upland and paddy field, respectively, which were higher than those of the check cultivar, by 7% and 2%, respectively. This cultivar would be suitable for an area of the Korean peninsula where the daily minimum temperature in January is above $-8^{\circ}C$.