• Polymer(Korea)
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• v.29 no.6
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• pp.599-604
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• 2005

The hyaluronic acid (HA) with excellent biocompatibility has been combined with lactide, the ester dimer of polylactide, with good biodegradability to produce biocompatible materials which can control the period of degradation in a human body. By freeze frying method, HA and lactide were crosslinked with crosslinking agent, 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC). Degree of lactide and EDC reaction was determined by the analysis of nuclear magnetic resonance spectroscopy. Both lactyl group and EDC conversion increased as the mole ratio of lactide to HA increased from 5 to 13. The membrane swelled less and became more brittle with the more addition of lactyl group resulting from the higher mole ratio of lactide to HA. Swelling ratio decreased and tensile modulus increased due to the more addition of lactyl group as the EDC concentration increased or reaction temperature decreased. Drug release experiment from various membranes with different degree of crosslinking showed that permeability decreased with increasing degree of crosslinking. The degradation became slower with the more addition of lactyl group. Mechanical property and degradation rate of the synthesized membrane were shown to be controlled through adjusting operation parameters such as mole ratio, temperature, and crosslinking agent concentration.

• Food Science of Animal Resources
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• v.20 no.3
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• pp.181-191
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• 2000

젖산균의 생장을 위한 질소, 탄소 공급원으로서 corn steep liquor의 이용 가능성을 시험하고 반응 표면 분석(Response surface metho-dology)을 이용하여 젖산균의 최적 생상 배지 조성을 연구하였다. 반응 표면 분석에서 L.fermentum의 생장배지에 첨가되 corn steep liquor와 yeast extract의 농도(p<0.01) 그리고 corn steep liquor와 yeast extract의 교호작용(P<0.05)이 L.ferm-entum의 생장에 큰 영향을 미치는 것으로 나타났으며, 이때 생균수가 최대인 corn steep liquor의 함량은 10.77%, yeast extract는 3.39%.Tween 80은 1.69%으로 예측되었다. 한편, Lc, lactis ssp. lactis 의 생장배지는 corn steep liquor 의 농도(P<0.01) 그리고 corn steep li-quor와 $\beta$-glycerophosphate disodium salt의 교호작용(P<0.05)인 Lc. lactis ssp. lactis의 생장에 큰 영향을 미치는 것으로 나타났으며 이때 생균수가 최대인 corn steep liquor의 함량은 3.5%, $\beta$-glycerophosphate disodium salt는 4.38%로 예측되었다. MRS broth와 예측된 최적 배지에서 L.fermentum의 젖산과 초산의 생성량은 각각 0.166, 0.114과 0.273, 0.081 M이고 M 17glc broth와 최적배지에서 Lc. lacti ssp. lactis의 젖산과 초산의 생성량은 각각 0.089, 0.003과 0.189, 0.003M이었다. 따라서 corn steep liquor는 L. fermentum와 Lc. lactis ssp, lactis 의 생장을 위해 질소 또는 탄소 공급원으로서 배지에 첨가 될 수 있는 우수한 농업 부산물로 판단되었다.

• Journal of the Korean Chemical Society
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• v.63 no.6
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• pp.446-452
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• 2019

We have developed a method that can leach Co, Mn, and Ni in the cathode active material safely using lactic acid. When cathode active material was leached by lactic acid, lactic acid showed the highest efficiency at 2 N than 1 N and above 4 N concentration. When the cathode active material was added incrementally into the solution of lactic acid, the maximum solubility was 30 g/L at 2 N concentration. Oxalic acid was added in the solution of lactic acid and it showed that rare metals represent the most economical recovery efficiency at 4 g/L. Based on this study, it was found that the optimal condition for recovery of rare metals from cathode active material is oxalic acid : cathode active material = 7 : 1 as a ratio of weight. In addition, it was observed that the precipitate produced by oxalic acid is a polynuclear crystalline material bonded with 3 components of Co, Ni, and Mn.

• Food Science and Preservation
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• v.23 no.3
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• pp.326-334
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• 2016

Omija (Schizandra chinensis) extract (OE) was fermented by using Lactobacillus plantarum EJ2014 to produce a beverage fortified with gamma-aminobutyric acid (GABA). After 2 days of fermentation in the presence of 2% monosodium glutamate (MSG) and 0.5% yeast extract (YE), the four-fold-diluted OE showed a higher viable cell count ($2.2{\times}10^9CFU/mL$) and lower acidity (1.2%) than that of the unfermented OE. In particular, addition of MSG as a precursor resulted in a small increase in the initial pH. MSG (2%) was completely converted to GABA (0.92%) during lactic acid bacteria fermentation for 3 days. Furthermore, the acidity of the fermented OE decreased from 1.74% to 0.56%. In addition, the original red color of the OE disappeared during LAB fermentation. However, when the fermented OE was mixed with 50% of the original OE, the original red color was recovered, with 19.56 and 13.92 for Hunter L and a values, respectively. The mixture of 50% original OE and 50% fermented OE showed the highest sensory score including the highest overall preference. In conclusion, the OE fortified with GABA and probiotics was produced by fermentation with a static culture, L. plantarum EJ2014.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.541-545
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• 1997

This study was conducted to investigate the effect of cocoon silk fibroin hydrolyzate(CSFH) on shelf-life extension of kimchi. CSFH was added in kimchi in the concentration of 0.3%(w/w), 0.6% and 0.9%. Kimchi with CSFH showed higher pH and lower titratable acidity than control and it was supposed that the growth of lactic acid bacteria was inhibited by CSFH. In model system, for complex lactic acid bacteria, CSFH showes antimicrobial activity.

• KSBB Journal
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• v.18 no.1
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• pp.70-73
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• 2003

TLC condition was developed for its simple separation and quantitative analysis of lactic acid. Rapid and clear separation of lactic acid by silica gel TLC plate was obtained by using nitromethane : 1-propanol : $H_2O$ (2 : 5 : 1.5, v/v/v) and a suitable dipping solution of 40 mg bromocresol purple in 100 mL 5% ethanol (pH 10.0). The lactic acid was shown as a bright yellow spot on a light cinnabar background. The quantitatively detectable concentration range of lactic acid was between 0.5 and 4% with 99.4%, confidence. Quantitative TLC analysis result was confirmed with HPLC and with enzymatic Quantitative analysis methods (by using lactate dehydrogenase).

• Journal of the East Asian Society of Dietary Life
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• v.25 no.1
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• pp.183-192
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• 2015

This study aimed to produce fermented extracts with sugar made from lotus root (LR) and Platycodon grandiflorum (PG), using lactic acid fermentation, and confirmed their physiological and anti-oxidative activities as basic data for manufacturing functional drinks through sensory tests. For the final sugar concentrations, PG showed $48.1^{\circ}brix$ and LR showed $52.0^{\circ}brix$. Sugar concentrations during lactic acid fermentation following dilution of sugar to $12^{\circ}brix$, ranged from $11.5{\sim}12.1^{\circ}brix$ for PG and $11.9{\sim}12.4^{\circ}C$ for LR. During lactic acid fermentation, lactic acid bacteria numbers tended to decrease in both fermented LR and PG extracts with sugar as the fermentation period increased. For DPPH radical scavenging ability, LR was three times higher in control without lactic acid fermentation while PG showed significant increases in L. acidophilus (77%), L. brevis (90%), and L. delbrueckii (177%) during lactic acid fermentation. For total polyphenol content, LR showed a higher concentration than PG, and except for fermented L. delbrueckii extract showing similarity with the control, contents of fermented extracts decreased. In the case of PG, CUPRAC, increased significantly in L. brevis, whereas FRAP, increased significantly in L. delbrueckii with lactic acid fermentation. For reducing power, except for fermentation with L. brevis, all PG showed lower reducing power activities. In the sensory test of fermented LR and PG extracts with sugar, both fermented extracts showed better results with L. brevis or L. delbrueckii than control or those with L. acidophilus in every item. Based on these results, it is highly possible to develop fermented extract drinks with sugar using LR or PG. In particular, lactic acid bacteria such as L. delbrueckii and L. brevis showed generally higher activities with potential as a functional drink.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.6
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• pp.829-832
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• 2003

To develop natural food preservatives, ethanol and water extracts were prepared from the cornus (Cornus of officianalis) and antimicrobial activities were examined against 10 microoganisms which were food borne pathogens and/or food poisoning microoganisms, food-related bacteria and yeasts. Ethanol extract exhibited antimicrobial activity for the microoganisms tested, except lactic acid bacteria and yeast. Especially, minimum inhibitory concentrations (MIC) of the ethanol extracts were determined as 0.25 mg/mL against bacteria and 2 mg/mL against target lactic bacteria and yeasts. Antimicrobial activity of the ethanol extracts were not destroyed by the heating at 121$^{\circ}C$ for 15 min and not affected by pH. The ethanol extract of cornus exhibiting high antimicrobial activities were fractionated in the other of diethylether and butanol fractions to test antimicrobial activity The antimicrobial activity adjust bacteria test was highest in the ethanol fraction.

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.235-236
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• 2014

군의 교육훈련간 디브리핑과 피드백 장치 활용을 통한 심폐소생술 교육방법을 적용하여 보다 효과적인 교육 방법을 확인하고 심폐소생술 수행 전 후 피로도를 검사하여 심폐소생술 술기가 숙달된 인원과 숙달되지 않은 인원의 피로도 차이를 분석함으로써 심폐소생술 교육프로그램의 기초자료를 제공하고자 한다. 현재 야전에서 응급처치교육을 받은 적이 없는 비 의무병인자로 전투병 생존법 교육 소집 대상자 중 참여 희망자 50명을 대상으로 하였다. 연구방법은 3가지 교육방법(디브리핑, 피드백장치, 디브리핑과 피드백장치 조합) 을 적용한 3개의 그룹에서 1,2,3차의 평가와 전체 디브리핑을 통해 심폐소생술 수행능력의 질적 향상에 미치는 영향과 동일 대상 중 희망자 20명에 한하여 심폐소생술 수행(5분) 전 후 혈중 젖산 농도 측정 및 주관적인 문답(1~10점)을 통해 심폐소생술 수행에 따른 피로도 실험을 진행하였다. 3가지 교육방법에 따른 심폐소생술수행능력 향상은 모든 그룹에서 유의하였으며(p<.001), 그룹별 심폐소생술 수행능력 향상효과의 차이는 디브리핑과 피드백장치를 조합하여 적용한 그룹에서 유의하게 높았다(p<.01). 심폐소생술 수행능력이 숙달되기 전 후의 피로도에 대해서는 본인이 느끼는 피로도는 유의한 차이는 없었으나 혈중 젖산농도에 따른 피로도는 유의한 차이로 전보다 후가 낮아졌다(p<.01).

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.37-43
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• 2018

Optimization of the lactic acid fermentation process was carried out to produce an old antler extract fortified with ${\gamma}$-aminobutyric acid (GABA). An old antler extract (OAE; 5%, w/v) obtained using a herbal extractor showed the highest contents of solids (1.75%) and proteins ($980{\mu}g/mL$). It also showed the highest total amino acid contents of $13,659{\mu}g/mL$, with glycine, proline, and glutamine concentrations of 1,945, 3,405, and $1,641{\mu}g/mL$, respectively. For the over-production of GABA, OAE was fermented with Lactobacillus plantarum EJ2014 in the presence of 0.5%, 1.5% glucose, and 3.5% MSG at $30^{\circ}C$ for 7 days. The fermented OAE showed high viable cell count of $2.0{\times}10^8CFU/mL$, pH of 6.56 and 0.77% acidity after 7 days. In particular, the acidity was greatly decreased by fermentation for 3 days, and 1.4% GABA was produced by the efficient conversion of the substrate, mono sodium glutamate.