• Title/Summary/Keyword: pH Indicator

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Isolation and Characterization of Prophage cured strain derivatives from Lactobacillus casei YIT 9018 (Lactobacillus casei YIT 9018로부터 Prophage cured strain의 분리 및 특성)

  • 이정준;김경태;백영진
    • Microbiology and Biotechnology Letters
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    • v.18 no.3
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    • pp.215-220
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    • 1990
  • Prophage cured strain derivatives from Luctobacillirs araei YIT 9018 were isolated from thermoinducible mutant of the parent lysogenic strain. Two thermoinducible mutants were isolated from L. casei YIT 9018 strain treated with N-methyl-N'-nitro-N-nitrosoguanidine. Prophage cured strains were selected after heat induction of thermoinducible strains at $42^{\circ}C$ for 30 min in MRT medium containing anti- 4 FSV serum. The prophage cured strains, L. casei HYM 1213 and L. casei HYM 4024, could be used an indicator strain for temperate phage $\phi$ FSW. The growth, lactic acid producing ability and carbohydrates fermentation of L. casei HYM 1213 were similar to the parent L. cmei YIT 9018 strain, but A. casei HYM 4024 was not. One of the prophage cured strain, L. cmei HYM 1213, could be used industrially .to produce lactic acid beverages because this strah could not induce the virulent phage$\phi$FSV. The physiological characterization of L. casei HYM 1213 strain was similar to the parent L. casei YIT 9018 strain.

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Evaluation of Largehead Hairtail Trichiurus lepturus Freshness Using Sensory and Chemical Analyses (갈치(Trichiurus lepturus)의 선도 판정을 위한 관능평가 및 화학적 분석에 따른 품질 평가)

  • Yu, Jeong-Wan;Kim, Hyeon-Jae;Seol, Da-Eun;Ko, Ji-Yun;Kim, Seong-Hee;Yang, Ji-Young;Lee, YangBong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.52 no.6
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    • pp.735-739
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    • 2019
  • The purpose of this study was to measure pH, trimethylamine (TMA), and total volatile basic nitrogen (TVB-N) as indicators of freshness during largehead hairtail Trichiurus lepturus storage, and to compare these indicators with those obtained by the sensory evaluation of quality index method (QIM) sensory evaluation. Largehead hairtail samples were stored at 4℃ and evaluated every 3 days until decay. The QIM sensory evaluation indicated scores of 0, 8.9, and 20 on storage days 0, 6, and 20, respectively. By day 15, the samples were completely decayed. The pH slowly increased during the storage period, reaching a maximum of 7.4. In the day 6, TMA and TVB-N contents were 2.97 and 15.57 mg/100 g, respectively. Thus, at 4℃, the largehead hairtail starts to decay after 6 days and, after 9 days, cannot be consumed safely

Selection of Beef Quality Factors Represented by Time-Temperature Integrator (TTI)

  • Kim, Eun-Ji;Kim, Kee-Hyuk;Jung, Seung-Won;Chung, Ku-Young;Lee, Seung-Ju
    • Food Science of Animal Resources
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    • v.32 no.5
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    • pp.598-603
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    • 2012
  • Beef qualities which can be properly predicted by time-temperature integrator (TTI), a chromatic indicator, were selected in terms of its similarity of temperature dependence between beef qualities and TTI, denoted by Arrhenius activation energy ($E_a$). The high similarity is required to afford accurate prediction. A devised enzymatic TTI based on laccase (an oxidase), which catalyses the oxidation on 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) producing color development, was applied. The factors of beef quality, such as volatile basic nitrogen (VBN), pH, color (CIE $L^*$, $a^*$), Warner-Bratzler shear force (WBSF), Pseudomonas spp. count, and lactic acid bacteria (LAB) count were considered for the selection. $E_a$ (55.48 kJ/mol) of the TTI was found to be similar to those of the beef qualities (all referred) in the order of LAB count (53.54 kJ/mol), CIE $a^*$ value (61.86 kJ/mol), pH (65.51 kJ/mol), Pseudomonas spp. Count (44.54 kJ/mol), VBN (67.98 kJ/mol), WBSF (40.67 kJ/mol), and CIE $L^*$ value (33.72 kJ/mol). The beef qualities with more similar $E_a$ to that of the TTI showed less difference between real and TTI predicted levels. In conclusion, it was found out that when applying TTI to food packages, their $E_a$ similarity should be checked to assure accurate estimation of food quality levels from TTI response.

Characterization of Lactobacillus reuteri BCLR-42 and Lactobacillus plantarum BCLP-51 as novel dog probiotics with innate immune enhancing properties

  • Kim, Eun Jin;Kang, Yeong Im;Bang, Tae Il;Lee, Myoung Han;Lee, Sang Won;Choi, In Soo;Song, Chang Seon;Lee, Joong Bok;Park, Seung Yong
    • Korean Journal of Veterinary Research
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    • v.56 no.2
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    • pp.75-84
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    • 2016
  • Probiotics that are able to provide beneficial effects on animal health have become important ingredients of dog foods. This study was conducted to characterize the probiotic potentials of two strains, Lactobacillus reuteri BCLR-42 and Lactobacillus plantarum BCLP-51, that were derived from feces of healthy dogs and evaluated based on tolerance to low pH and bile acid, antimicrobial activities, enzyme profiles, sensitivity to antibiotics, and innate immune enhancing potentials. Both strains showed survival of more than 90% at pH 3 and 0.2% bile acid and exhibited broad antimicrobial activities against indicator bacteria. Moreover, both strains showed high sensitivity to antibiotics, except vancomycin, metronidazole, and gentamicin. The alkaline phosphatase was negligible (score 0), whereas they showed strong beta galactosidase activity (score range 5 or 3, respectively). The phagocytosis and oxidative burst activities of canine granulocytes were significantly enhanced in response to both strains. These results show that both strains have the capability to act as probiotics and the potential for application as ingredients in dog foods.

Modulation of Chemical Carcinogen-Induced Unscheduled DNA Synthesis by Dehydroepiandrosterone (DHEA) in the Primary Rat Hepatocytes

  • Kim, Seung-Hee;Han, Hyung-Mee;Kang, Seog-Youn;Jung, Ki-Kyung;Kim, Tae-Gyun;Oh, Hye-Young;Lee, Young-Kyung;Rheu, Hang-Mook
    • Archives of Pharmacal Research
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    • v.22 no.5
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    • pp.474-478
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    • 1999
  • Modulation of unscheduled DNA synthesis by dehydroepiandrosterone (DHEA) after exposure to various chemical carcinogens was investigated in the primary rat hepatocytes. Unscheduled DNA synthesis was induced by treatment of such direct acting carcinogens as methly methanesulfonate (MMS) and ethyl methanesulfonate (EMS) or procarcinogens including benzo(a)pyrene (BaP) and 7, 12-dimethylbenz(a)anthracene (DMBA). Unscheduled DNA synthesis was determined by measuring [methyl-3H]thymidine radioactivity incorporated into nuclear DNA of hepatocytes treated with carcinogens in the presence or absence of DHEA. Hydroxyurea $(5{\times}10^{-3} M)$was added to growth medium to selectively suppress normal replication. DHEA at concentrations ranging from $(1{\times}10^{-6} M)$ to$(5{\times}10^{-4} M)$ did not significantly inhibit unscheduled DNA synthesis induced by either MMS $(1{\times}10^{-4} M)$ or EMS $(1{\times}10^{-2} M)$. In contrast, DHEA-significantly inhibited unscheduled DNA synthesis induced by BaP $(6.5{\times}10^{-5} M)$ and DMBA.$(2{\times}10^{-5} M)$. DHEA-induced hepatotoxicity in rats was examined using lactate dehydrogenase (LDH) release as an indicator of cytotoxicity. DHEA exhibit no significant increase in LDH release compared with the control at 18 h. These data suggest that nontoxic concentration of DHEA does not affect the DNA excision repair process, but it probably influence the enzymatic system responsible for the metabolic activation of procarcinogens and thereby decreases the amount of the effective DNA adducts formed by the ultimate reactive carcinogenic species.

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Dietary Iron Intake and Body Iron Status of Myocardial Infarction Patients in Chunan Area

  • Kim, Hee-Seon
    • Journal of Community Nutrition
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    • v.1 no.2
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    • pp.140-147
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    • 1999
  • It has been known for some time that elevated body iron could be a risk factor for coronary heart disease. The present study was conducted to determine body iron status and dietary iron intake of patients with myocardial infarction(MI). Seventy five patients from the Chunam area with their first MI history within he past 2 months were recruited. The serum iron concentration, total iron binding capacity(TIBC) and percent transferrin saturation(TS) were selected as indicators of body iron status. Twenty four hour recall was conducted by trained interviewers to asses the dietary intake. Most women (91.3%) showed waist to hip ratio(W/H) greater than 0.85 while 17.3% of men were assessed to have a tendency of abdominal obesity(W/H>0.95). The average BMI of women was 25.80 and that of men was 23.98. The average diet intake of participants was below the recommended dietary allowances (RDA) for most nutrients. He average dietary iron intake was 10.03 mg/day for all subjects while women's iron intake was significantly lower than men's. However, a great proportion of participants (77%) showed a tendency to have normal iron status. About 9% of the participants were assessed as iron deficient and 14% had an iron overload. The mean serum iron concentration was 125 g/dl ranging from 13.3 to 280.6 g/dl. Iron intake from animal sources were significantly associated with body iron status (r=0.257, p=0.026) when TIBC was used as an iron status indicator. When iron status was assessed with TS, it was directly associated with iron intake from animal sources(r=0.278, p=0.05) for he subjects in the normal iron status group. He results of the present study showed that the nutrient intake of Mi patients in Chunan was not quite adequate while iron status was mostly in the normal range. Further studies are needed to investigated whether there is a possible difference in iron metabolism of the MI patients.

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Detection of C-Reactive Protein Using Direct-binding Quartz Crystal Microbalance Immunosensor (직접결합방식 수정진동자 면역센서에 의한 C-Reactive Protein 검출)

  • Kim, N.;Kim, D.K.;Cho, V.J.
    • KSBB Journal
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    • v.22 no.6
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    • pp.443-446
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    • 2007
  • A prognostic indicator of coronary heart disease, C-reactive protein, was tried to be determined by a batch-type quartz crystal microbalance immunosensor. The sensor was operated by direct-binding mode and the optimum concentration for the corresponding antibody for immobilization was $50{\mu}g/ml$. The reaction buffer for the system was 0.1 M sodium phosphate (pH 7.0) and system operation was performed in the order of baseline stabilization, analyte addition and measurement, and regeneration of the sensor chip with 10 mM NaOH. When plotted in double-logarithmic scale, the sensor showed a linear detection range of 0.27-106.00 nM for rat C-reactive protein with the limit of detection of 0.53 nM. It also showed a good reusability.

The Review of Metabolic Acidosis During Exercise (운동 시 대사적 산성화에 관한 고찰)

  • Yoon, Byung-Kon
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.4
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    • pp.1433-1441
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    • 2018
  • The development of acidosis during intense exercise has traditionally been explained by the increased production of lactic acid which causes the release of a proton and the formation of the acid salt sodium lactate. Through this explanation, when the rate of lactate production is high enough to exceed cellular proton buffering capacity, cellular pH is decreased. This biochemical process has been termed lactic acidosis. This belief has been an interpretation that lactate production causes acidosis and fatigue during intense exercise. However, this review provides clear evidence that there is no biochemical support for lactate production causing acidosis and fatigue. Metabolic acidosis is caused by an increased reliance on nonmitochondrial ATP turnover. Lactate production is essential for muscle to produce cytosolic $NAD^+$ to support continued ATP regeneration from glycolysis. In addition, Lactate production consumes protons. Although lactate accumulation can be a good indirect indicator for decreased cellular and blood pH, that is not direct causing acidosis.

The Sanitary Characteristics of Differenct Commercial Seasoned Shrimp Soy Sauce (시판 간장새우살장의 위생 특성)

  • Lee, Jong Soo;Lim, Jeong Wook;Kim, Hye Jin;Park, Sun Young;Kim, Ye Jin;Shon, Suk Kyung;Kim, Jin-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.53 no.6
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    • pp.851-860
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    • 2020
  • Shrimp in seasoned soy sauce (S-SS) is a popular seafood product in Korea, but it could be potentially hazardous; thus, this study was conducted to investigate its safety. Commercial S-SS were collected and analyzed for pH, volatile basic nitrogen (VBN), hygenic indicator microorganisms (viable cell count, coliforms, and Escherichia coli), food poisoning bacteria (Staphylococcus aureus, Vibrio parahaemolyticus, and Listeria monocytogenes), preservatives (dehydroacetic acid, sorbic acid, benzoic acid, and its salt, parahydroxybenzoate), tar colorants, and sensory properties. Domestic and foreign standards were also investigated for S-SS. Commercial S-SS ranged from to 6.2-7.3 for pH, 13.7-39.1 mg/100 g for VBN, and 4.6-6.9 log CFU/g for viable cells. The coliforms and E. coli of commercial S-SS were from ND to 3.4 log CFU/g and negative, respectively. Food poisoning bacteria, preservatives, and tar colorants were not detected in commercial S-SS. Only the coliform count and presence of E. coli in commercial S-SS exceeded the set standards of vietnam, while all items were within domestic and foreign standards.

The Effects of the Perceived Motivation Type toward Corporate Social Responsibility Activities on Customer Loyalty (기업사회책임활동적인지인지동기류형대고객충성도적영향(企业社会责任活动的认知认知动机类型对顾客忠诚度的影响))

  • Kim, Kyung-Jin;Park, Jong-Chul
    • Journal of Global Scholars of Marketing Science
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    • v.19 no.3
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    • pp.5-16
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    • 2009
  • Corporate social responsibility (CSR) activities have been shown to be potential factors that can improve corporate image and increase the ability of corporations to compete. However, most previous studies related to CSR activities investigated how these activities influence product and corporate evaluation, as well as corporate image. In addition, some researchers treated consumers' perceptions of corporate motives as moderator variables in evaluating the relationship between corporate social responsibilities and consumer response. However, motive-based theories have some weaknesses. Corporate social responsibility activities cause two motives(egoistic vs. altruistic) for consumers, but recently, Vlachos et al. (2008) argued that these motives should be segmented. Thus, it is possible to transform the original theory into a modified theory model (persuasion knowledge model, PKM). Vlachos et al. (2008) segmented corporate social responsibility motives into four types and compared the effects of these motives on customer loyalty. Prior studies have proved that CSR activities with positive motives have positive influences on customer loyalty. However, the psychological reasons underlying this finding have not been determined empirically. Thus, the objectives of this research are twofold. First, we attempt to determine why most customers favor companies that they feel have positive motives for their corporate social responsibility activities. Second, we attempt to measure the effects of consumers' reciprocity when society benefits from corporate social responsibility activities. The following research hypotheses are constructed. H1: Values-driven motives for corporate social responsibility activities have a positive influence on the perceived reciprocity. H2: Stakeholder-driven motives for corporate social responsibility activities have a negative influence on the perceived reciprocity. H3: Egoistic-driven motives for corporate social responsibility activities have a negative influence on perceived reciprocity. H4: Strategic-driven motives for corporate social responsibility activities have a negative influence on perceived reciprocity. H5: Perceived reciprocity for corporate social responsibility activities has a positive influence on consumer loyalty. A single company is selected as a research subject to understand how the motives behind corporate social responsibility influence consumers' perceived reciprocity and customer loyalty. A total sample of 200 respondents was selected for a pilot test. In addition, to ensure a consistent response, we ensured that the respondents were older than 20 years of age. The surveys of 172 respondents (males-82, females-90) were analyzed after 28 invalid questionnaires were excluded. Based on our cutoff criteria, the model fit the data reasonably well. Values-driven motives for corporate social responsibility activities had a positive effect on perceived reciprocity (t = 6.75, p < .001), supporting H1. Morales (2005) also found that consumers appreciate a company's social responsibility efforts and the benefits provided by these efforts to society. Stakeholder-driven motives for corporate social responsibility activities did not affect perceived reciprocity (t = -.049, p > .05). Thus, H2 was rejected. Egoistic-driven motives (t = .3.11, p < .05) and strategic-driven (t = -4.65, p < .05) motives had a negative influence on perceived reciprocity, supporting H3 and H4, respectively. Furthermore, perceived reciprocity had a positive influence on consumer loyalty (t = 4.24, p < .05), supporting H5. Thus, compared with the general public, undergraduate students appear to be more influenced by egoistic-driven motives. We draw the following conclusions from our research findings. First, value-driven attributions have a positive influence on perceived reciprocity. However, stakeholder-driven attributions have no significant effects on perceived reciprocity. Moreover, both egoistic-driven attributions and strategic-driven attributions have a negative influence on perceived reciprocity. Second, when corporate social responsibility activities align with consumers' reciprocity, the efforts directed towards social responsibility activities have a positive influence on customer loyalty. In this study, we examine whether the type of motivation affects consumer responses to CSR, and in particular, we evaluate how CSR motives can influence a key internal factor (perceived reciprocity) and behavioral consumer outcome (customer loyalty). We demonstrate that perceived reciprocity plays a mediating role in the relationship between CSR motivation and customer loyalty. Our study extends the research on consumer CSR-inferred motivations, positing them as a direct indicator of consumer responses. Furthermore, we convincingly identify perceived reciprocity as a sub-process mediating the effect of CSR attributions on customer loyalty. Future research investigating the ultimate behavior and financial impact of CSR should consider that the impacts of CSR also stem from perceived reciprocity. The results of this study also have important managerial implications. First, the central role that reciprocity plays indicates that managers should routinely measure how much their socially responsible actions create perceived reciprocity. Second, understanding how consumers' perceptions of CSR corporate motives relate to perceived reciprocity and customer loyalty can help managers to monitor and enhance these consumer outcomes through marketing initiatives and management of CSR-induced attribution processes. The results of this study will help corporations to understand the relative importance of the four different motivations types in influencing perceived reciprocity.

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