• Title/Summary/Keyword: L-lactic acid

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Effects of Safflower Seed Powder on the Quality Characteristics of Kimchi (홍화씨 분말 첨가가 김치의 품질에 미치는 영향)

  • 박우포;박규동;엄현섭
    • Food Science and Preservation
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    • v.9 no.2
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    • pp.200-204
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    • 2002
  • This study was carried out to investigate the effect of safflower powder on the characteristics of kimchi. Quality indexes were pH, titratable acidity, reducing sugar content, microbial counts, and sensory evaluation. Safflower powder enhanced the decrease in pH and increase in titratable acidity during fermentation at l0$^{\circ}C$, and the changes were more conspicuous until 15 days. Stabilized levels in pH was attained, but steady increase in titratable acidity was shown after that time. Microbial loads of total and lactic acid bacteria showed a faster stationary phase for kimchi samples with safflower powder than control. Control was better scores in sensory evaluation, but there were no significant differences in aroma and taste except sample with 3% safflower powder.

Cellular-uptake Behavior of Polymer Nanoparticles into Consideration of Biosafety

  • Do, Jeong-Hoe;An, Jeong-Ho;Joun, Yong-Seung;Chung, Dong-June;Kim, Ji-Heung
    • Macromolecular Research
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    • v.16 no.8
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    • pp.695-703
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    • 2008
  • Nanoparticles have tremendous potential in cancer prevention, detection and augmenting existing treatments. They can target tumors, carry imaging capability to document the presence of tumors, sense pathophysiological defects in tumor cells, deliver therapeutic genes or drugs based on the tumor characteristics, respond to external triggers to release an appropriate agent, document the tumor response, and identify the residual tumor cells. Nanoparticles < 30 nanometers in diameter show unexpected and unique properties. Furthermore, particles < 5 nanometers in size can easily penetrate cells as well as living tissues and organs. This study evaluated the safety of nano materials in a living body and the relationship between the living tissue and synthetic nano materials by examining the in-vitro cytotoxicity of poly(lactic-co-glycolic) acid (PLGA) nano-spheres and fluorescein isothiocynate(FITC)-labeled dendrimers as polymer nanoparticles. PLGA was chosen because it has been used extensively for biodegradable nanoparticles on account of its outstanding bio-compatibility and its acceptance as an FDA approved material. The dendrimer was chosen because it can carry a molecule that recognizes cancer cells, a therapeutic agent that can kill those cells, and a molecule that recognizes the signals of cell death. Cytotoxicity in L929 mouse fibroblasts was monitored using MTT assay. Microscopic observations were also carried out to observe cell growth. All assays yielded meaningful results and the PLGA nanoparticles showed less cytotoxicity than the dendrimer. These nano-particles ranged in size from 10 to 100 nm according to microscopy and spectroscopic methods.

Effect of Thyme and Rosemary on The Quality Characteristics, Shelf-life, and Residual Nitrite Content of Sausages During Cold Storage

  • Jin, Sang Keun;Choi, Jung Seok;Lee, Seung Jae;Lee, Seung Yun;Hur, Sun Jin
    • Food Science of Animal Resources
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    • v.36 no.5
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    • pp.656-664
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    • 2016
  • The effects of thyme and rosemary on the quality characteristics of sausages during cold storage were investigated. Sausages were prepared with thyme and rosemary powder (1 and 2%) and stored for 6 weeks at 10℃. The pH was significantly decreased in sausages by addition of thyme and rosemary compared to that observed in the control before and after storage. At 4 weeks of storage, the residual nitrite content was decreased by thyme and rosemary compared to the control. Lightness (L*) and yellowness (b*) were increased during storage, whereas redness (a*) and whiteness (W) were decreased before and after storage by addition of thyme and rosemary. The amount of TPC and lactic acid bacteria was lower at the end of storage in sausage containing thyme and rosemary. The 2, 2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging capacity of sausages was increased by addition of thyme and rosemary compared to that in the control before and after storage. In particular, T2 (0.2% thyme addition) showed the highest DPPH radical scavenging capacity during storage. In a sensory evaluation, flavor and overall acceptability were lower in sausages containing thyme and rosemary than in the control. However, at the end of storage (6 wk), aroma, flavor and overall acceptability were not significantly different among the sausage samples.

Expression of manB Gene from Escherichia coli in Lactococcus lactis and Characterization of Its Bifunctional Enzyme, Phosphomannomutase

  • Li, Ling;Kim, Seul Ah;Fang, Ruosi;Han, Nam Soo
    • Journal of Microbiology and Biotechnology
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    • v.28 no.8
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    • pp.1293-1298
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    • 2018
  • Phosphomannomutase (ManB) converts mannose-6-phosphate (M-6-P) to mannose-1-phosphate (M-1-P), which is a key metabolic precursor for the production of GDP-D-mannose used for production of glycoconjugates and post-translational modification of proteins. The aim of this study was to express the manB gene from Escherichia coli in Lactococcus lactis subsp. cremoris NZ9000 and to characterize the encoded enzyme. The manB gene from E. coli K12, of 1,371 bp and encoding 457 amino acids (52 kDa), was cloned and overexpressed in L. lactis NZ9000 using the nisin-controlled expression system. The enzyme was purified by Ni-NTA column chromatography and exhibited a specific activity of 5.34 units/mg, significantly higher than that of other previously reported ManB enzymes. The pH and temperature optima were 8.0 and $50^{\circ}C$, respectively. Interestingly, the ManB used in this study had two substrate specificity for both mannose-1-phosphate and glucose-1-phosphate, and the specific activity for glucose-1-phosphate was 3.76 units/mg showing 70% relative activity to that of mannose-1-phosphate. This is the first study on heterologous expression and characterization of ManB in lactic acid bacteria. The ManB expression system constructed in this study canbe used to synthesize rare sugars or glycoconjugates.

Effect of Chitosan-Liquid Calcium Addition on the Quality of Kimchi during Fermentation (키토산-액상칼슘 첨가 김치의 숙성 중 품질에 미치는 영향)

  • Jang, Se-Young;Jeong, Yong-Jin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.5
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    • pp.715-720
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    • 2005
  • This study was carried out to investigate the effect of chitosan-liquid calcium (CLC) on the high-calcium kimchi fermentation. The $0.5\%$ of CLC retarded the decreasing rate of pH and the increasing rate of titratable acidity, and these effects were more conspicuous with liquid calcium. Total microbes and lactic acid bacteria counts were lower in CLC $(0.5\%)$ added kimchi during fermentation. The a-value of kimchi juice was gradually increased but the L- and b-values were decreased. The calcium content of the kimchi supplemented with $0.5\%$ of CLC was maintained in the range of $207\~228\;mg\%$. In sensory evaluation test of $0.5\%$ CLC-added kimchi, the staled flavor was decreased, the crispness was maintained and the overall taste was increased to highest level after 15-day fermentation.

Physiological Effects of Different Underwear Materials Thermoregulatory Response during Exercise with Sweating at Cold Environments (한랭환경하에서 운동발한시 인체의 체온조절반응에 대한 내의소재의 생리학적 의의)

  • Kwon, Oh-Kyung;Kim, Tae-Kyu;Son, Du-Hun;Park, Sung-Han
    • Fashion & Textile Research Journal
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    • v.1 no.1
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    • pp.43-49
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    • 1999
  • This study conducted 4 different kinds of underwear materials, which were A (Cotton 100%), B (Wool 100%), C (Cotton/Wool, 50/50%) and D (Acrylic/Cotton, 50/50%) and were done in a climate chamber under cold ambient $10{\pm}1^{\circ}C$, $40{\pm}5%RH$ by 6 male subjects who were in good health. Physiological parameters such as rectal and local skin temperature(forehead, forearm, hand, trunk, thigh, leg, foot, back and chest), heart rate, body weight loss, clothing microclimate, blood lactic acid concentration, and wearing sensation were measured. Started with a 15-min rest period, 15-min of exercise 1 (the condition of 4.5 mile/hr walking speed equivalent to with 8.5 Kcal energy consumption on the treadmill) period, 15-min rest period, exercise 2 (after 3minutes warming-up at 3.0. 3.7, 4.5. 5.2. 6.0, 6.7 mile/hr) until exhaustion period, and final 15-min of recovery period were performed. The results were as follows: The lowest mean skin temperature was acrylic/cotton in order of wool > cotton/wool > cotton > acrylic/cotton (F=13. 79. p<0.00l). Most of all skin temperature by parts of body had turned out in sequence of temperature wool > cotton/wool > acrylic/cotton > cotton. Fore arm part showed highest temperature about $32.43^{\circ}C$ on wool and had a tendency approximately $1.8^{\circ}C$ higher than cotton which had the lowest temperature, and had the biggest difference among garments in terms of skin temperature. The back temperature within clothing showed about $2^{\circ}C$ higher than the chest temperature within clothing. but the back humidity within clothing showed about 4~12% higher than the chest humidity within clothing. Body weight loss by each garment was this sequence; cotton > acrylic/cotton > wool > cotton/wool.

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Fermentation and Quality of Kimchi Prepared wth Chiness Cabbages Harvested from Field and Hydroponic Cultivation

  • Kim, Soon -Dong;Kim, Mee -Kyung;Youn, Kwang -Sup;No, Hong-Kyoon;Han, Duck-Chul
    • Preventive Nutrition and Food Science
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    • v.4 no.4
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    • pp.241-245
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    • 1999
  • The potential of hydroponic cultivated Chinese cabbage as a kimchi material was evaluated. The hydroponic-grown (HG) Chinese cabbage was heavier in weight, taller in height, wider in width, but less in number of leaves compared with the field-grown (FG) Chinese cabbage. The former showed higher contents of calcium, iron, vitamin A and niacin, and lower lipid and vitamin C than the latter. During fermentation of 28 days at 1$0^{\circ}C$, FG and HG kimchis showed comparable pH and acidity values, besides that the FG and HG kimchis showed a pH value of 4.2 and 4.0, respectively, at the 14th day. The FG kimchi showed higher numbers of total microbes as well as total and typical lactic acid bacteria than the HG kimchi at the 7th day. However, both kimchis did not show any difference at 14th day. There was no significant difference in the {TEX}$L^{*}${/TEX} value between FG and HG kimchis. However, HG kimchi showed a more reddish hue than FE kimchi between the 7th and 14th day of fermentation. In sensory evaluation, the HG kimchi revealed a slightly more sour taste and a less crispy texture than the FE kimchi at the 14th day. However, both kimchis did not show any difference in overall quality until the 21st day of fermentation.

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Isolation and Characterization of Some Promoter Sequences from Leuconostoc mesenteroides SY2 Isolated from Kimchi

  • Park, Ji Yeong;Jeong, Seon-Ju;Kim, Jeong A;Kim, Jeong Hwan
    • Journal of Microbiology and Biotechnology
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    • v.27 no.9
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    • pp.1586-1592
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    • 2017
  • Some promoters were isolated and characterized from the genome of Leuconostoc mesenteroides SY2, an isolate from kimchi, a Korean traditional fermented vegetable. Chromosomal DNA of L. mesenteroides SY2 was digested with Sau3AI and ligated with BamHI-cut pBV5030, a promoter screening vector containing a promoterless cat-86. Among E. coli transformants (TFs) resistant against Cm (chloramphenicol), 17 were able to grow in the presence of $1,000{\mu}g/ml$ Cm and their inserts were sequenced. Transcription start sites were examined for three putative promoters (P04C, P25C, and P33C) by primer extension. Four putative promoters were inserted upstream of a promoterless ${\alpha}$-amylase reporter gene in $pJY15{\alpha}$. ${\alpha}$-Amylase activities of E. coli TFs containing $pJY15{\alpha}$ (control, no promoter), $pJY03{\alpha}$ ($pJY15{\alpha}$ with P03C), $pJY04{\alpha}$ (with P04C), $pJY25{\alpha}$ (with P25C), and $pJY33{\alpha}$ (with P33C) were 66.9, 78.7, 122.1, 70.8, and 99.3 U, respectively. Cells harboring $pJY04{\alpha}$ showed 1.8 times higher activity than the control. Some promoters characterized in this study might be useful for construction of food-grade expression vectors for Leuconostoc sp. and related lactic acid bacteria.

Probiotics Inhibit Lipopolysaccharide-Induced Interleukin-8 Secretion from Intestinal Epithelial Cells

  • Oh, Hyun-Wook;Jeun, Gi-Hoon;Lee, Jin;Chun, Tae-Hoon;Kim, Sae-Hun
    • Food Science of Animal Resources
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    • v.32 no.4
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    • pp.434-440
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    • 2012
  • It has been suggested that probiotics could be useful for the prevention of symptomatic relapse in patients with inflammatory bowel disease (IBD). Interleukin (IL)-8 has been well recognized as one of the pro-inflammatory cytokines that could trigger inflammation and epithelial barrier dysfunction. In this study, the anti-inflammatory effects of probiotics were investigated using a human epithelial cell line (HT-29). Probiotics from infant feces and kimchi were tested for their cytotoxicity and effects on adhesion to epithelial cells. The present results show that seven strains could form 70 % adhesion on HT-29. The probiotics used in this study did not affect HT-29 cell viability. To screen anti-inflammatory lactic acid bacteria, HT-29 cells were pretreated with live and heat-killed probiotics, and lipopolysaccharide (LPS) ($1{\mu}g/mL$) was then added to stimulate the cells. The cell culture supernatant was then used to measure IL-8 secretion by ELISA, and the cell pellet was used to determine IL-8 and toll-like receptor (TLR-4) mRNA expression levels by RT-PCR. Some probiotics (KJP421, KDK411, SRK414, E4191, KY21, and KY210) exhibited anti-inflammatory effects through the repression of IL-8 secretion from HT-29 cells. In particular, Lactobacillus salivarius E4191, originating from Egyptian infant feces, not only decreased IL-8 mRNA expression, but also decreased TLR-4 expression. These results indicate that Lactobacillus salivarius E4191 may have a protective effect in intestinal epithelial cells.

Comparison of Nanopowdered and Powdered Ginseng-added Yogurt on Its Physicochemical and Sensory Properties during Storage

  • Lee, Su-Bin;Ganesan, Palanivel;Kwak, Hae-Soo
    • Food Science of Animal Resources
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    • v.33 no.1
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    • pp.24-30
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    • 2013
  • This study was conducted to compare the physicochemical and sensory properties of yogurt added with nanopowdered ginseng (NPG) and powdered ginseng (PG) of different concentrations (0.1, 0.3, 0.5, and 0.7%) (w/v) during the storage at $7^{\circ}C$ for 20 d. The pH and viscosity values of yogurt added NPG or PG decreased during the storage. The pH values of the yogurt samples were ranged from 4.0 to 4.6 as a reflective of the fresh state. Viscosity values of yogurt with NPG at lower concentrations 0.1 and 0.3% (w/v) showed higher values during increased storage time. DPPH radical scavenging activity was significantly higher in the NPG-added yogurt than in the PG during the storage period (p<0.05). The lactic acid bacteria (LAB) counts ranged from $3.0{\times}10^9$ to $1.3{\times}10^9$ and $2.2{\times}10^9$ to $1.1{\times}10^9CFU/mL$ in 0.3% NPG and PG-added yogurts, respectively. Increased storage period showed decrease in LAB counts irrespective of the type of ginseng powder and storage period. In sensory test, 0.1 and 0.3% NPG-added yogurt showed similar results to control in yellowness, viscosity, and bitterness. Based on the data obtained from the present study, it was concluded that the concentrations 0.1 and 0.3% (w/v) of NPG could be used to produce NPG-added yogurt without significant adverse effects on physicochemical and sensory properties, and enhance functional value of yogurt.