• Title, Summary, Keyword: fermentation

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The Quality Characteristics of Chunggujang Prepared by Bacillus Subtilis NRLSI IV on the Different Inoculum Levels and Fermentation Times (Bacillus Subtilis NRLSI IV로 제조한 청국장의 접종포자농도와 발효시간에 따른 품질 특성)

  • Kim Kyung-Mi;Kim Haeng-Ran;Park Hong-Ju
    • The Korean Journal of Community Living Science
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    • v.17 no.3
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    • pp.123-131
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    • 2006
  • To compare the quality characteristics, chunggugjang was prepared with Bacillus subtilis NRLSI IV on the different inoculum levels$(10^2,\;10^4,\;10^6,\;and\;10^8 CFU/ml)$ and fermentation times(0, 12, 24, 36, and 48 hours). Although significant change in total nitrogen content was not found, the content of amino type, soluble and ammonia type nitrogen was generally increased according to the increase in fermentation time. Decomposition rate of nitrogen was also increased by fermentation time and nitrogen solubility was the highest value(62-75.9%) at 48 hour fermentation. In results of color changes, it was found that L and a value were decreased but there was no significant changes in b value as fermentation time was increased. In chunggugjang made with long fermentation time, hardness was decreased and relative viscosity of viscous substance was gradually decreased after little increase at initial fermentation time. The effect of inoculum level on hardness and relative viscosity were similar to that of fermentation time, i.e. the decrease of these at high inoculum level. In activity of V-GTP, 36 hour incubation could produce the highest value whereas no effect of inoculum level was found during fermentation except at 48 hour. In chunggugjang made with $10^2CFU/mL$ of Bacillus subtilis NRLSI IV, the content of glucose, sucrose, raffinose and stachyose was dramatically decreased at initial fermentation time and that of phytic acid, oxalic acid, citric acid, tartaric acid and malic acid was also decreased during fermentation, although the increase in acetic acid was found.

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Effect of Fermentation Temperature on Quality of Doenjang (숙성온도가 된장의 품질에 미치는 영향)

  • Kim, Moon-Seok;Kim, Eun-Mi;Chang, Kyu-Seob
    • Korean Journal of Agricultural Science
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    • v.35 no.1
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    • pp.1-9
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    • 2008
  • There were four types of Doenjang fermentation as following conditions for investigation ; 1) low temperature fermentation at $13^{\circ}C$ for 180 days, 2) low temperature at $13^{\circ}C$ for 7 days to room temperature at $30^{\circ}C$ for 10 days, to low temperature at $13^{\circ}C$ for 163 days, and for 173 days, 3) low temperature at $13^{\circ}C$ 7 days to room temperature at $30^{\circ}C$, 4) room temperature at $30^{\circ}C$ for 180 days. There were no changes of moisture, NaCl and total nitrogen content during fermentation period of four types conditions, but pH and amino type nitrogen decreased in room temperature at $30^{\circ}C$ for 180 days. It required 3 times more fermentation period until same quantity of the amino type nitrogen. The low temperature fermentation sample was lower than room temperature fermentation sample in pH and amino type nitrogen. The yeast decreased in low temperature fermentation sample taken 15 to 30 days longer than room temperature sample. The yeast is increased up to 30 days, and decreased little by little. After 60 days, it remained a few without effectiveness on the Doenjang quality. The low temperature fermentation sample showed brighter than room temperature fermentation sample. Different fermentation condition affected Doenjnag quality, especially, low temperature fermentation sample showed bright color in Doenjnag. So low temperature fermentation must be expected as good method for getting high quality Doenjnag.

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The Fermentation Characteristics of Saccharomyces cerevisiae F38-1 a Thermotolerant Yeast Isolated for Fuel Alcohol Production at Elevated Temperature (연료용 알콜의 고온발효를 위해 분리한 고온성 효모균주 Saccharomyces cerevisiae F38-1의 발효 특성)

  • 김재완;김상헌;진익렬
    • Microbiology and Biotechnology Letters
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    • v.23 no.5
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    • pp.624-631
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    • 1995
  • The fermentation characteristics of Saccharomyces cerevisiae F38-1, a newly isolated thermotolerant yeast strain from a high temperature environment have been studied using a fermentation medium containing 20% glucose, 0.2% yeast extract, 0.2% polypeptone, 0.3% (NH$_{4}$)$_{2}$SO$_{4}$, 0.1% KH$_{2}$PO$_{4}$, and 0.2% MgSO$_{4}$ without shaking at 30$\circ$C to 43$\circ$C for 5 days. The fermentability was over 90% at 30$\circ$C, 88% at 37$\circ$C, 77% at 40$\circ$C and 30% at 43$\circ$C. A similar fermentation result was obtained at pH between 4 and 6 at 30$\circ$C and 40$\circ$C. Aeration stimulated the growth of the strain at the beginning of the fermentation, but it reduced alcohol production at the end of alcohol fermentation. Optimal glucose concentration was determined to be between 18 and 22% at 40$\circ$C as well as 30$\circ$C, but the growth was inhibited at the glucose concentration of over 30%. A fermentability of over 90% was observed at 40$\circ$C in 2 days when the medium was supplemented by 2% yeast extract. A higher inoculum size increased the initial fermentation rate, but not the fermentation. A fermentability of over 90% was achieved in 2 days at 40$\circ$C in a fermentor experiment using an optimized medium containing 20% glucose and 1% yeast extract.

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The effect of the ammonium thiocyanate on the fermentation of the yeasts.(Saccharomyces brenerei-Hefe-Rasse XII, Saccharomyces formosensis No. 396 IAM) and Saccharomyces cerevisiae IAM) (Ammonium thiocyanate 농도가 주정효모(Saccharomyces brenerei Hefe-Rasse XII, Saccharomyces formosensis No. 396 IAM) 및 맥주효모(Saccharomyces cerevisiae IAM)의 발효작용에 미치는 영향)

  • 조운복;이상태
    • Korean Journal of Microbiology
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    • v.6 no.1
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    • pp.29-35
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    • 1968
  • There are many reports on the effect of salts to the fermentation of the yeasts, but there are a few reports on the effect of the ammonium thiocyanate(NH$_4CNS$) on the fermentation of the yeasts(Saccharomyces brenerei-Hefe-Rasse X11, Saccharomyces formosensis No. 396 IAM and Saccharomyces cerevisiae IAM). A study has been made on the effects of the ammonium thiocyanate on the fermentation of the above yeasts. The results of the research are as belows: 1) The addition of 0. 00001 mol. of ammonium thiocyanate makes the fermentation of the yeast(Sacch. formosensis No. 39 IAM) facilitate, but has not influenced the another yeast (Sacch. brenerei-Hefe-Rasse XII). 2) The addition of 0. 001 mol. of ammonium thiocyanate makes fermentation of Rases XII the fastest, but the on other yeast (Sacch. formosensis No - 396 IAM) was accelerated by the addition of 0. 1 mol., and it seems to have abnormal fermentation by the addition of 0. 0001 mol. The addition of ammonium thiocyanate(0. 00001-0. 001 mol.) inhibited the fermentatirn of the yeast(Sacch. cerevisiae IAM), but the concentration of 0. 1 mol. does not interrupt the fermentation of Sacch. cerevisiae IAM and increased the fermentation. 3) The order of effects to the fermentation of each yeast is Sacch. brenerei-Hefe-Rasse XII, Sacch. formosensis No. 396 IAM, Sacch. cerevisiae IAM.

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Antioxidative Materials in Domestic Meju and Doenjang 1.Lipid Oxidation and Browning during Fermentation of Meju and Doenjang (재래식 메주 및 된장중의 항산화성 물질에 관한 연구 1. 메주 발효 및 된장 숙성중의 지질산화와 갈변)

  • 이종호;김미혜;임상선
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.20 no.2
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    • pp.148-155
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    • 1991
  • Lipid oxidation and browning during fermentation of domestic Meju and Doenjang were examined in order to elucidate the antioxidative effects of browning products and phenol compounds from Meju and Doenjang. Peroxide values of lipids from Meju were detectable and slightly increased until 3 weeks of fermentation, but started to be decreased after 3 weeks of fermentation and notdetectable after 6 weeks. Peroxides were not detected in Doenjang during the whole fermentation, but started to be decreased after 3 weeks of period of 22 weeks fermentation. Carbonyl value were increased during the whole period of Meju fermentation, but started to be decreased at the early stage of Doenjang fermentation. Hydrophilic fraction of browning products from Meju was much higher than lipophilic fraction and the former fraction was dramatically increased at the early stage of the fermentation. But the both fractions maintained high values during Doenjang fermentation. Hydrophilic browning products and phenol and phenol compound in Meju showed strong antioxidative against linoleic acid.

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Bacterial Contamination and Its Effects on Ethanol Fermentation

  • Chang, In-Seop;Kim, Byung-Hong;Shin, Pyong-Kyun;Lee, Wan-Kyu
    • Journal of Microbiology and Biotechnology
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    • v.5 no.6
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    • pp.309-314
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    • 1995
  • Samples were collected from a commercial ethanol production plant to enumerate the bacterial contamination in each step of a starch based ethanol production process. Though the slurry of raw material used in the process carried bacteria with various colony morphology in the order of $10^4$ per ml, only the colonies of white and circular form survived and propagated through the processes to the order of $10^8$ per ml at the end of fermentation. Almost all of the bacterial isolates from the fermentation broth were lactic acid bacteria. Heterofermentative Lactobacillus fermentum and L. salivarius, and a facultatively heterofermentative L. casei were major bacteria of an ethanol fermentation. In a batch fermentation L. fermentum was more detrimental than L. casei to ethanol fermentation. In a cell-recycled fermentation, ethanol productivity of 5.72 g $I^{-1} h^{-1}$ was obtained when the culture was contaminated by L. fermentum, whilst that of the pure culture was 9.00 g $1^{-1} h^{-1}$. Similar effects were observed in a cell-recycled ethanol fermentation inoculated by fermentation broth collected from an industrial plant, which showed a bacterial contamination at the level of 10$^8$ cells per ml.

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Novel Starter Culture for Kimchi, Using Bacteriocin-producing Enterococcus faecium Strain (Enterococcus faecium bacteriocin 생산균주를 starter로 이용한 김치의 제조)

  • 하덕모;차동수
    • Microbiology and Biotechnology Letters
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    • v.22 no.5
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    • pp.550-556
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    • 1994
  • For an extension of the palatable stage in Kimchi which was limited by further lowering pH as the fermentation proceeds, the starter culture of bacteriocin-producing Enterococcus faecium DU 0267 obtained from Kimchi was added at the preparation time, and pH, bacteriocin activity, growth of lactic acid bacterial group and gas production in Kimchi were examined during the fermentation at 10, 20 and 30$\circ$C . The pH of Kimchi fell rapidly to 4.0~4.2 in the early fermentation stage, and then, has gone down very slowly throughout further fermentation. The lactic acid bacte- ria, particularly lactobacilli and leuconostoc, were remarkably slower in its growth than those in the control. Although the patterns of these change during fermentation at different temperatures were similar, these effects by the addition of starter were enhanced at 10 and 20$\circ$C. The bacteriocin activity was increased rapidly during log phase of the bacteriocin producer strain in the early fermentation stage of Kimchi and reached their maximum after fermentation at 10$\circC, for 8 days and at 20 or 30$\circ$C for 2 days. Thereafter, the activity disappeared quickly. The gas production by fermentation was also suppressed considerably, and their volume produced after fermentation at 20$\circ$C for 14 days corresponded to 60% of those of the control.

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Investigation into the Ecological and Natural Dyeing with Medicinal Plants after Fermentation by NURUK and the Effect of Natural Additives

  • Park, Youngmi
    • Textile Coloration and Finishing
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    • v.24 no.4
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    • pp.260-269
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    • 2012
  • The aim of this study was to develop higher-value added dyeing materials with the fermentation-dyeing -mordanting system using only the natural ingredients by integrating traditional fermentation techniques with traditional dyeing technique. Nuruk, which is used mainly to ferment traditional foods, was used as a fermenting agent to ferment 5 different types of materials. Acidic burnt alum and alkaline calcium hydroxide were used as natural mordants. The dyeability checked after fermentation showed that both cotton and silk mordanted with Gardenia jasminoides did not show notable changes, and 10 days of fermentation was found to be appropriate. Sophora japonica L. performed better on cotton materials mordanted with slaked lime, and alkaline mordants were found to be more effective than acidic ones. With Rheum coreanum, a fermentation period of more than 24 days ($5^{th}$ fermentation) worked best on cotton material, showing a 5 fold increase in the K/S value after the $5^{th}$ slaked lime fermentation than with no fermentation. Rhus javanica L. was found to increase the color fastness to gentle washing and the fastness to light was found to possess 4 means that natural dyed fabric have the highest level of durability, the grade 1 the lowest level of fastness.

Effect of Bamboo (Pseudosasa japonica Makino)Leaves on the Physicochemical Properties of Dongchimi (대나무(이대)잎이 동치미의 발효 중 이화학적 특성에 미치는 영향)

  • 김미정;장명숙
    • Korean journal of food and cookery science
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    • v.15 no.5
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    • pp.459-468
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    • 1999
  • The purpose of this study was to evaluate the effect of bamboo(Idae) leaves on the taste and preservation of Dongchimi. Dongchimi was prepared by the method described in the literatures and fermented at 10$^{\circ}C$ for 75 days. The amounts of bamboo leaves used to cover the Donchimi was 1, 3, 5 and 7% of radish weight. Total vitamin C content increased gradually in the initial stage of the fermentation periods, and then it decreased gradually. Regardless of the amount of bamboo leves, the reducing sugar content increased gradually from the initial stage of fermentation increased rapidly after 8 days of fermentation. As the amount of bamboo leaves increased, the reducing sugar content was retained longer, which reflected the retardation of Dongchimi fermentation. The free amino acid contents in all of the Dongchimi samples were in order of arginine > glutaric acid > aspartic acid > alanine at the initial period of fermentation, but the order changed to arginine > alanine > glutamic acid > valine as fermentation proceeded over 23 days. Among the five non-volatile organic acids identified, the levels of malic acid and citric acid were decreased during fermentation, while those of lactic acid, fumaric acid, and succinic acid were increased. There was a significant increase in lactic acid, succinic acid, malic acid, and citric acid contents during fermentation. The content of water soluble pectin(WSP) was higher than other pectins at the initial stages, but the content of WSP decreased as fermentation proceeded.

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