• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.688-691
• /
• 2000

Ferritin, an iron-storage protein, is found in bacteria and some animal tissues such as liver, spleen, and bone marrow. It is more effective and causes less side reactions than the traditional ferrous sulfate, and thus has been used primarily to treat iron deficiency in pregnancy anaemia. Currently, the ferritin extracted from the bovine and equine spleens are sold as a commercial product. Its market is estimated as several hundreds of million US dollars. However, because of the recent warnings against the viral diseases of animal origins such as mad cow disease, a safer ferritin is sought after. Our research team has successfully developed a production process for recombinant human ferritin. Its expression titer from yeast is high enough to be economically viable, and its particle formation characteristics are as effective as well.

• Food Science and Preservation
• /
• v.3 no.2
• /
• pp.171-178
• /
• 1996

This study was carried out for the purpose of improving the persimmon vinegar. The acetic acid bacteria strain JST-3, using acetic acid fermentation was isolated from the traditional persimmon vinegar. The optimum conditions for high yield of acetic acid were studied in the shaking bath. Acetic acid bacteria was cultured at 3$0^{\circ}C$ for 4 days and transferred to persimmon alcoholic juice for acetic acid fermentation. The optimum initial acidity for acetic acrid fermentation was 1%(w/v) and the addition of glucose or yeast extract was observed to produce relatively low yield of acetic acid. Succinic and acetic acid were major organic acid in the persimmon vinegar, The contents of lactic acid which was known to increase off-flavor were very low. Sensory evaluation revealed that the persimmon vinegar prepared in this study was superior to two commercial ones in the aroma and taste.

• The Korean Journal of Food And Nutrition
• /
• v.13 no.2
• /
• pp.158-163
• /
• 2000

Killer yeast, Hansenular capsulata S-13 were treated with heat, ethylmethane sulfonate and N-methyl-n'-nitro-n-nitrosoguanidine and a mutant(S13-E1), showing 2-fold higher killer toxin activity than that of parent strain to killer sensitive strain, Saccharomyces cerevisiae ATCC 38026 was obtained. Hansenular capsulata S13-E1 showed strong killer toxin activity to Saccharmyces mellis and Saccharomyces sal년 and four strains of gas-producing yeasts from traditional Doenjang and Kochujang. The culture condition for killer toxin production by Hansenular capsulata S13-E1 was optimized to be 1.0% potato extract, each 0.5% of peptone and glucose, and 0.025% MgSO4 with initial pH 4.5 at 3$0^{\circ}C$ and 36 hr of batch cultivation.

• Journal of the East Asian Society of Dietary Life
• /
• v.14 no.4
• /
• pp.379-386
• /
• 2004

Jeung-Pyun is a traditional Korean fermented rice cake leavened by yeast. To develop a functional Jeung-Pyun, mulberry leaf(ML) were added to the rice at the levels of 0, 2, 4, 6, 8%, respectively. Physicochemical, sensory, texture and surface characteristics of Jeung-Pyun were examined. The specific volumes of all the Jeung-Pyun's with ML were significantly lower than that of control(0% ML) and 4% ML sample showed the highest volume among them. The pH of ML Jeung-Pyun batters decreased with fermentation time. Overall quality of Jeung-Pyun with ML obtained lower value than the control. Among the texture properties measured with rheometer, hardness, cohesiveness, gumminess and brittleness of ML Jeung-Pyun decreased according to the amount ML added and springiness was not significantly different. The surface structure by SEM showed that Jeung-Pyun added with 4% ML had the largest and the most uniform air cells. In conclusion, the most acceptable concentrations of ML on the basis of overall quality in sensory evaluation and physicochemical characteristics were 2% or 4%.

• Journal of the East Asian Society of Dietary Life
• /
• v.2 no.1
• /
• pp.17-33
• /
• 1992

Information about processing method of Kwahaju can get from the 41 kinds classical literature traditional yakju. The contents of those classical literature consist of sixty items about Kwahaju, number of art-less-brewed alcoholics and compounded alcoholics. Interpreted content was classified and analyzed. Selected 40 items, about Kwahaju among previous 60 items, compounded brewages, were distributed into two groups of alcoholics ; Seoul Kwahaju and Kimchun Kwahaju. Both group of alcoholics, grunded on the periodical conversion of processing method through four centuries were set one thing to another and analyzed. The materials used for Kwahaju, compounded alcoholics, were waxy rice mainley, regular rice, yeast(Nuruk), wheat, barley seedings and Soju, Kwahaju, usually, is brewed for worm or hot season and store up the alcoholics for summer. It should be reminded to be durable alcoholics, not soon pureficated out or needing repair.

• Applied Biological Chemistry
• /
• v.48 no.3
• /
• pp.228-232
• /
• 2005

A yeast strain producing phytase, isolated from a mash of Korean traditional Yakju, was identified as a strain of Saccharomyces cerevisiae and designated as Saccharomyces cerevisiae CY strain. Phytase was produced by CY strain both intracellularly and extracellularly. Total phytase activity by the shaking culture was about two times higher than that of the static culture. The portion of extracellular phytase to total phytase activity ranged between 23 and 49 percent, depending on the glucose concentration in the culture medium. Phytase production was reached at approximately 1 U/ml as total phytase activity and the maximum intracellular phytase activity was 0.17-0.19 U/mg-DCW at late logarithmic growth phase. The optimum reaction pH and temperature of intracellular phytase were 3.5 and $40^{\circ}C$, respectively. Over 95% of the phytate was degraded by growing cells after 36 hours yeast cell culture and about 90% of total phytate was effectively degraded by suspending the whole cell with the biomass of 0.4 mg-DCW/ml-reaction solution after 12 hours degradation reaction.

• Fisheries and Aquatic Sciences
• /
• v.14 no.3
• /
• pp.192-197
• /
• 2011

The objective of this study was to select an effective microbial strain to improve the functional qualities of Eisenia bicyclis water extract by fermentation. For this purpose, several microorganisms isolated from traditional Korean fermented foods were inoculated and cultivated in E. bicyclis water extract. Ultimately, yeast strain YM-1 was selected for further study based on its total phenolic compound (TP) content and antioxidant activity, which were enhanced by microbial fermentation. The extract fermented by YM-1 exhibited a superior TP content and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity compared to extracts fermented by other microbes. The highest TP content and DPPH radical scavenging activity were observed after one day of YM-1 fermentation. Yeast strain YM-1 was identified as Candida utilis based on an analysis of its physiological characteristics. During fermentation of the extract by C. utilis YM-1, no significant difference was observed in the proximate composition, including moisture, crude lipid, crude protein, and crude ash. Fermentation by C. utilis YM-1 resulted in enhanced biological activity, including increases in the TP content and antioxidant activity. Thus, fermentation by C. utilis YM-1 is an attractive strategy for developing value-added food ingredients.

• Journal of Life Science
• /
• v.14 no.5
• /
• pp.815-820
• /
• 2004

A bacterum containing antitumor activity was isolated from traditional korean food, Jeotgal. Through the 16s rRNA sequence analysis, the bacterium was identitied as a strain of Bacillus subtilis SW-l. The best culture condition for antitumor activity of the bacterium is 3% of soluble starch and 1 % of yeast extract as corbon and nitrogen sources, respectively. Cytotoxicitic concentrations of the culture supernatant of B. subtilis SW-1 against cancer cell lines, A549 and SK-OV3 were 30 ul/ml and 40 ul/ml, respectively, as $IC_{50}$/ values. In DNA fragmentation assay, the culture supernatant showed the programmed cell death (apoptosis) to cause degrading the chromosomal DNA like ladder. Taken together, the culture supernatant of the B. subtilis SW-1 has some possibility to be used as an antitumor agent.

• Food Science of Animal Resources
• /
• v.33 no.3
• /
• pp.325-330
• /
• 2013

Kefir is traditional fermented milk produced by various lactic acid bacteria (LAB) and yeast, which produce lactic acid, ethanol, carbon dioxide, and other flavor compounds. The purpose of this study was to evaluate the effects of different commercial oligosaccharides, such as maltotriose, fructooligosaccharide (FOS), galactooligosaccharide (GOS), and isomaltooligosaccharide (IMO), on the fermentation properties of kefir. First, we determined the acidification kinetic parameters, such as $V_{max}$, $t_{max}$(h), $t_{pH5.0}$(h), and $t_f$(h) of fermented milk supplemented with 4% (w/w) of different oligosaccharides. The probiotic survival and chemical composition (pH, organic acids profile, and ethanol content) of kefir during fermentation were also measured. Compared to control fermentation, all oligosaccharides increased acidification rate and reduced the time to complete fermentation (pH 4.7). The addition of FOS, in particular, resulted in the lowest $t_f$(h) and the highest populations of LAB and yeast during fermentation. All oligosaccharides increased ethanol production during fermentation. Further, significant differences were observed in the formation rates of six organic acids during fermentation. This study provided comparative data on the properties of commercial oligosaccharides for kefir manufacturing. Consequently, FOS especially had the potential for adequate and effective oligosaccharides in commercial kefir for the improvement of cost- and time-effectiveness.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.55 no.6
• /
• pp.769-776
• /
• 2022

As an aquatic plant, the lotus leaf Nelumbo nucifera is rich in polyphenols, carotenoids, and flavonoids. We analyzed the chemical (pH, acidity, sugar, alcohol), microbiological (lactic acid bacteria, yeast), and antioxidant activity of Makgeolli supplemented with 5% and 10% lotus leaf (ll) during fermentation for 7 days. The pH of the non-additive group (control) was 3.10-6.03, that of the 5% added group was 3.17-5.77, and that of the 10% added group was 3.27-5.70, which decreased significantly (P<0.05) as the fermentation time elapsed. The acidity and sugar content were 1.89-2.12% and 9.10-12.90 Brix, respectively, which were significantly higher (P<0.05) as the amount of added ll increased. The alcohol content was 5.90-7.20% and was the highest on the seventh day of fermentation. The lactic acid bacteria was 6.07-7.17 log CFU/mL, which was higher in ll Makgeolli. Yeast increased until day 3 and then decreased to 3.27-5.86 log CFU/mL. DPPH (1,1-diphenyl-2-picrylhdrazyl) and ABTS [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)] radical scavenging activities were higher in ll Makgeolli (DPPH 68.72-81.48%, ABTS 90.71-91.67%). In this study, the commercialization potential of ll Makgeolli was expanded by enhancing the quality and antioxidant function of Makgeolli added with ll.