• 제목/요약/키워드: Lactic acid

검색결과 4,039건 처리시간 0.029초

동결 및 동결건조가 Lactic Starter Cell에 미치는 영향 (Effect of Freezing and Lyophilization on Lactic Starter Cell)

  • 이상기;박무영
    • 한국미생물·생명공학회지
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    • 제8권1호
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    • pp.19-25
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    • 1980
  • 난산균의 효율적인 보존문제로서 Lactobacillus bulgaricus NLS-4를 사용하여 동결 및 동결건조법이 이 균주의 생존도 및 활성도에 미치는 영향을 조사하였다. 동결 및 동결건조처리 후 전반적인 생존도 및 활성도는 저하되나 초발미생물농도를 높여준 경우 모두 증대되어 동결시에는 최고 생존도 및 활성도가 각각 46% 및 0.25% lactic acid였고 동결건조 시에는 22% 및 0.29% lactic acid였다. 동결 및 동결건조 처리전 보호물질로서 각각 10% glycerol과 G. C. G. S. 현탁용액을 첨가한 경우 대조군인 10% skim milk를 첨가한 경우보다 생존도 및 활성도가 증가하여 동결시에는 최고 생존도 62%, 최고 비교활성도 95%를 나타냈고 동결건조시에는 각각 79%, 126%를 나타냈다. 결론적으로는 미생물농도가 생존도 및 활성도를 높이기 위한 가장 중한 인자임을 알 수 있었고 보호물질의 첨가도 효과적임을 알 수 있었다.

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젖산과 옥살산을 이용한 폐 이차 리튬이온 전지 양극 활물질로부터 희유금속들의 회수 (Recovery of Rare Metals from the Waste Secondary Lithium Ion Battery Cathode Active Materials Using Lactic Acid and Oxalic acid)

  • 김연정;한지선;최식영;오인경;홍용표;유건상
    • 대한화학회지
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    • 제63권6호
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    • pp.446-452
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    • 2019
  • 젖산을 이용하여 안전하게 양극활물질에 있는 Co, Mn, Ni을 침출할 수 있는 방법을 개발하였다. 양극활물질을 젖산으로 침출 시켰을 때, 젖산의 농도는 1N과 4 N 이상에서 보다는 2 N에서 가장 높은 효율을 보였다. 양극활물질을 단계적으로 젖산 용액에 첨가 하였을 때, 최대 용해도는 2 N의 젖산 용액에서 1 L 당 30 g이었다. 젖산 용액에 옥살산을 첨가하였고 희유금속들은 1 L 당 4 g에서 가장 경제적인 회수율을 보였다. 본 연구를 바탕으로 해서, 양극활물질로부터 희유금속들을 회수하기 위한 최적의 조건은 무게비로 옥살산과 양극활물질이 7 : 1이라는 것을 확인할 수 있었다. 첨가하여, 옥살산에 의해서 생성된 침전물은 Co, Ni, Mn 3성분이 결합되어 있는 다핵 결정성 물질이었다.

Evaluating Commercial Spray Applications of Lactic Acid, Hot Water, and Acidified Sodium Chlorite for the Reduction of Escherichia coli on Beef Carcasses

  • Kang, Dong-Hyun;Lee, Sun-Young
    • Food Quality and Culture
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    • 제2권1호
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    • pp.55-60
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    • 2008
  • This study examined the effects of lactic acid spray, hot water spray, or their combined treatment, as well as the effects of acidified sodium chlorite (ASC), for the decontamination of Escherichia coli on beef carcass surfaces using a commercial intervention system. With this system, the effects of 2 or 4% lactic acid (v/v), hot water ($89{\pm}1^{\circ}C$), or their combined treatment, were examined in terms of reducing inoculated E. coli. ASC (266 ppm), which was adjusted to pH 2.5 using acetic acid or citric acid, was applied using a hand-held spray system. When the beef carcasses were treated with 2 or 4% lactic acid for 10.4 s, less than 1 log reductions of inoculated E. coli were observed. A hot water spray treatment for 9.8 s resulted in a 2.1 log reduction of inoculated E. coli. However, when the hot water was followed with either 2 or 4% lactic acid, no difference in E. coli reduction was found between the hot water alone or the combined treatment with lactic acid. When ASC was adjusted to pH 2.5 with acetic acid and citric acid, 3.8 and 4.1 log reductions of E. coli were observed, respectively. Overall, the lactic acid spray treatment was least effective, and the ASC treatment was most effective, for the E. coli decontamination of beef carcasses. Therefore, these data suggest that ASC would be a more effective intervention against E. coli than most of the methods currently being used. However, more research is required to evaluate the effects of ASC on other organisms, as well as to identify application methods that will not affect meat quality.

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냉면용 동치미액 제조를 위한 항균 활성이 높은 젖산균의 선발 (Screening of high Antibacterial Lactic Acid bacteria for the Preparation of Dongchimi-Juice for Naengmyon)

  • 조신호
    • 한국식품영양학회지
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    • 제12권1호
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    • pp.69-76
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    • 1999
  • In order to screen lactic acid bacterial starter having high antibacterial activity and giving good flavor in Dongchmi for Naengmyon antibacterial activity and acid producing ability of 24 strains of Kimchi lactic acid bacteria were tested. Among 24 strains tested Leuconostoc mesenteroides subsp. mesenteroides C16, Leu. paramesenteroides C18 Lactobacillus bavaricus B01, B06, C19, C32 Lac. homohiochii B21 and B22 showed high antibacterial activity and their antibacterial activities were more active against Listeria monocytogenes and Staphylococcus aureus than against Escherichia coli and Salmonella typhimurium. The odors of Dongchimi-juices fermented with Leu. mesenteroides or Leu. paramesenteroides were more favorable than those with Lac. bavaricus or Lac. homohiochii. But the odors of Naengmyon-broths which were made with each Dongchimi-juice were not significantly different each other. In consideration of antibacterial ac-tivity and flavor of Dongchimi-juice two strains of lactic acid bacteria Lac. homohiochii B21 and Leu. mes-enteroides subsp. mesenteroides C16 were finally screened out as Dongchimi starters.

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이온음료 제조를 위한 동치미의 최적 담금 조건에 관한 연구 (Studies on the Optimum Fermenting Conditions of Dongchimi for Production of Ion Beverage)

  • 고은정;허상선;박만;최용희
    • 한국식품영양과학회지
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    • 제24권1호
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    • pp.141-146
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    • 1995
  • 본 연구의 목적은 이온음료 제조를 위한 동치미 최적 담금 조건을 설정하고자 각 담금 조건 소금농도 2.0, 2.4%, 숙성온도 0.5, $10^{\circ}C$에 따른 동치미액의 성분 분석을 행하였다. pH 감소속도 및 총산도는 동치미의 숙성온도가 높을수록 빠른 증가경향을 나타내었으며 유기산은 lactic acid, citric acid, malic acid가 검출되었고, 그 중 lactic acid 생성량이 가장 많았으며 succinic acid는 $0^{\circ}C$ 숙성 말기에 미량 검출되었다. 젖산균은 염도에 관계없이 숙성초기에 증가하다가 감소하는 경향을 나타내었고 젖산균이 증가하는 기간에 lactic acid 함량도 증가하는 경향을 나타내어 젖산균수와 lactic acid 함량 변화는 일치하는 경향을 보여주고 있다. 휘발성 성분은 3-methyl pentane, ethyl thioethene, 2,3-diaza-indolizine, dimethyl disulfide 등으로 추정되었다. 이온 음료 제조를 위한 최적 담금 조건은 비휘발성 유기산이 최대로 검출되는 최적 숙기인 pH 4.2~3.9, 산도 0.1~0.4에 이르는 동치미로 $0^{\circ}C$에서 24~29일, $5^{\circ}C$에서 9~12일, $10^{\circ}C$에서 16~22 숙성시킨 동치미를 최적 담금조건으로 설정하고자 한다.

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김치의 위생학적 우수성 (Hygienic Superiority of Kimchi)

  • 김용석;신동화
    • 한국식품위생안전성학회지
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    • 제23권2호
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    • pp.91-97
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    • 2008
  • Kimchi is a representative traditional food in Korea and a type of vegetable product that is the unique complex lactic acid fermentation in the world. It can be considered as a unique fermented food generated by various flavors, which are not included in raw materials, that can be generated by mixing and fermenting various spices and seasonings, such as red pepper powder, garlic, ginger, and salted fish, added to Chinese cabbages. Functionalities in Kimchi have been approved through several studies and the probiotic function that is mainly based on lactic acid bacteria including their physical functions in its contents has also verified. Studies on the verification of the safety of Kimchi including its physiological functions have been conducted. In particular, the function of lactic acid bacteria, which is a caused of the fermentation of Kimchi. Although the lactic acid bacteria contributed to the fermentation of Kimchi is generated from raw and sub-materials, the lactic acid bacteria attached on Chinese cabbages has a major role in the process in which the fermentation temperature and dominant bacteria are also related to the process. The salt used in a salt pickling process inhibits the growth of the putrefactive and food poisoning bacteria included in the fermentation process of Kimchi and of other bacteria except for such lactic acid bacteria due to the lactic acid and several antimicrobial substances generated in the fermentation process, such as bacteriocin and hydrogen peroxide. In addition, the carbon dioxide gas caused by heterolactic acid bacteria contributes to the inhibition of aerobic bacteria. Furthermore, special ingredients included in sub-materials, such as garlic, ginger, and red pepper powder, contribute to the inhibition of putrefactive and food poisoning bacteria. The induction of the change in the intestinal bacteria as taking Kimchi have already verified. In conclusion, Kimchi has been approved as a safety food due to the fact that the inhibition of food poisoning bacteria occurs in the fermentation process of Kimchi and the extinction of such bacteria.

Fermentative Quality of Guineagrass Silage by Using Fermented Juice of the Epiphytic Lactic Acid Bacteria (FJLB) as a Silage Additive

  • Bureenok, S.;Namihira, T.;Tamaki, M.;Mizumachi, S.;Kawamoto, Y.;Nakada, T.
    • Asian-Australasian Journal of Animal Sciences
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    • 제18권6호
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    • pp.807-811
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    • 2005
  • This experiment examined the characteristics of fermented juice of epiphytic lactic acid bacteria (FJLB) prepared by the addition of glucose, sucrose and molasses as a fermentation substrate. The effect of FJLB on the fermentative quality and changes in chemical composition during fermentation of guineagrass silage were also investigated. The pH value of the silages treated with FJLB rapidly decreased, and reached to the lowest value within 7 days of start of fermentation, as compared to the control. The number of lactic acid bacteria (LAB) in the treated silages increased for the first 3 days, thereafter the number of LAB declined gradually up to the end of the experiment. Silages treated with FJLB had larger populations of LAB than the control. Ammonia-nitrogen production increased throughout the ensiling period, which in the control and no-sugar added FJLB silages were higher than the other treated silages. Lactic acid levels varied with the time of ensiling and among the silage treatments. For any sugar FJLB treated silages, the lactic acid increased initially, and then slightly reduced to less than 50 g/kg of dry matter until 49 days after ensiling, except the silage treated with glucose added FJLB. Nevertheless, lactic acid content of the control decreased constantly from the beginning of ensiling and was not found after 35 days. Moreover, acetic acid content increased throughout the ensiling period. All the FJLB treated silages had significantly (p<0.05) lower pH and ammonia-nitrogen content, while significantly (p<0.05) higher lactic acid content and V-score value compared with the control. This study confirmed that the applying of FJLB with any sugar substrate improved fermentative quality of silage.

밀가루 입국과 유산균을 이용하여 만든 Seed mash를 첨가한 발효액종의 특성 (Characteristics of Flour Ferment with Seed Mash Containing Wheat Flour Koji and Lactic Acid Bacteria)

  • 이명구;강상모;이시경
    • Applied Biological Chemistry
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    • 제49권2호
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    • pp.97-102
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    • 2006
  • 빵의 노화와 풍미 향상을 목적으로 빵 제조시 첨가하기 위하여 제조한 유산균, 효모, seed mash을 첨가하여 배양한 발효액종(flour ferment)의 특성을 조사한 결과는 다음과 같다. Seed mash를 첨가하지 않은 발효액종은 배양 6시간 경과시 pH와 TTA가 각각 5.6 및 2.5이었으며, seed mash 5%와 각기 다른 유산균을 첨가한 발효액종은 pH가 4.63-4.69와 TTA가 9.0-9.9이었다. 4시간 발효시킨 발효액종에 함유된 유기산은 대조구의 경우 프로피온산이 0.09mg/g, 젖산과 초산이 각각 0.06 및 0.04 mg/g 검출되었으며, seed mash와 효모만을 발효시킨 발효액종에서는 프로피온산이 0.21 mg/g, 젖산과 초산이 각각 0.16, 0.06 mg/g, seed mash와 유산균, 효모를 혼합 배양한 발효액종에서는 젖산이 0.23-0.27 mg/g으로 가장 높았으며, 프로피온산이 0.21 mg/g, 초산이 0.06-0.08 mg/g 검출되었다. 발효액종의 향기성분은 seed mash, 효모, 유산균을 혼합 배양한 발효액종에서 ethyl caprylate, ethyl caproate, ethyl acetate, ethyl caprate, phenylethyl acetate등의 에스테르 화합물이 대조구에서 보다 많이 검출되었다.

Effect of addition of lactic acid bacteria on quality of rye silage harvested at early heading stage

  • Kuppusamy, Palaniselvam;Choi, Ki-Choon;Srigopalram, Srisesharam;Ilavenil, Soundharrajan;Park, Hyung-Su;Jung, Jeong Sung
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.285-285
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    • 2017
  • This study is aimed to analyze the effect of lactic acid bacteria inoculants (LAB) on quality of rye silage fermentation, harvested at early heading stage. The nutritive values were similar between the control and LAB inoculated silages. The pH of rye silage in LAB inoculation significantly decreased as compared to control (p<0.05). In addition, the content of lactic acid in LAB inoculation significantly increased (p<0.05), but the content of acetic acid in LAB treatments decreased. In addition, lactic acid bacterial counts in LAB inoculation significantly increased as compared to control (p<0.05). Therefore, we suggest that rye silage could be improved by novel lactic acid inoculation.

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