• 한국식품영양학회지
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• 제13권4호
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• pp.319-327
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• 2000

배추김치에 0.25% chitosan, 0.5% chitosan, 0.5% chitosan+0.04M Na-malate, 0.5% chitosan+0.04M Na-lactate, 0.5% chitosan+04M Na-citrate를 첨가하여 김치의 숙성 과정 중 pH, 산도, pH/TA ratio, ascorbic acid 함량 및 Pectin질의 변화에 대한 영향을 알아보았다. 그 결과는 다음과 같다. 1. 김치의 숙성과정 중 pH는 감소하는 경향을 보였으며, 대조군, 0.25% chitosan 첨가군, 0.5% chitosan 첨가군, 0.5% chitosan+Na-citrate 첨가군, 0.5% chitosan+Na-malate 첨가군, 0.5% chitosan+Na-lactate 첨가군의 순으로 감소하였다. 2. 김치의 숙성과정 중 산도는 증가하는 경향을 보였으며, 대조군, 0.5% chitosan+Na-malate 첨가군, 0.25% chitosan 첨가군, 0.5% chitosan+ Na-citrate 첨가군. 0.5% chitosan 첨가군, 0.5% chitosan+Na-lactate 첨가군의 순으로 증가하였다. pH/TA ratio는 김치의 숙성 중 감소하는 경향을 보였으며. 대조군, 0.25% chitosan 첨가군, 0.5% chitosan+Na-malate 첨가군, 0.5% chito-san+Na-citrate 첨가군, 0.5% chitosan+Na-lactate 첨가군의 순으로 감소하였다. 3. Ascorbic acid 함량은 3일째에 가장 높은 함량을 보였으며, 0.5% chitosan에 유기산염 병용첨가군이 다른 군들보다 월등히 높았다. 그 후 숙성기간이 경과할수록 감소하였다. 4. AIS 함량의 변화는 숙성기간이 지날수록 모두 감소하는 경향을 보였으며, 대조군, 0.25% chit-osan 첨가군, 0.5% chitosan 첨가군, 0.5% chito-san+Na-citrate 첨가군, 0.5% chitosan+Na-lactate 첨가군, 0.5% chitosan+Na-citrate 첨가군 순으로 감소하였다. 5. AIS로부터 펙틴을 추출하여 HWSP, HXSP, HCISP로 분획한 함량비는 대조군이 숙성이 진행됨에 따라 HWSP가 증가하고 HCISP는 감소하는 경향을 보인 반면, chitosan 첨가군은 숙성이 진행됨에 따라 HWSP가 감소하고 HCISP는 증가하는 경향을 나타내었다. 위와 같은 결과로부터 chitosan의 첨가는 김치의 보존성 향상에 효과를 보였으며. 유기산염과 병용첨가군이 단독첨가군보다 더욱 효과적이었다. 유기산염의 종류에 따른 병용에 있어서는 Na-lactate 첨가군이 Na-citrate와 Na-malate 첨가군보다 효과적으로 나타났다.

• 한국식품과학회지
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• 제32권6호
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• pp.1285-1290
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• 2000

본 실험은 수소이온 농도, 염, Sodium tripolyphosphate(STPP) 농도에 따른 돈육 등심 드립의 열변성을 DSC를 이용하여 조사한 것이다. pH가 증가함에 따라 돈육 등심 드립의 열안정성은 증가하였으며 특히 $T_1$이 $pH\;5.5{\sim}6.0$에서 $6.33^{\circ}C$의 가장 큰 증가를 보였다. 0.1 N, 0.2 N NaOH/1, 2 N HCl 및 $0{\sim}5%$ NaCl과 $0{\sim}0.5%$ sodium tripolyphosphate(STPP)로 처리하였을 때, pH가 증가함에 따라 드립의 열안정성은 증가하였으며, 특히 $T_1$이 $pH\;5.5{\sim}6.0$에서 $6.33^{\circ}C$의 가장 큰 증가를 보였다. 그리고 NaCl농도의 증가는 드립의 열안정성을 감소시켰는데 그중 $T_1$은 5% NaCl농도 수준에서 $9.41^{\circ}C$의 감소를 보였다. 한편 STPP는 드립이 열안정성을 증가시켰으며 0.5% STPP농도 수준에서 $T_1$이 $5.84^{\circ}C$의 증가를 보였다. $40{\sim}100^{\circ}C$로 증가함에 따라 $Lightness(L^*)$는 41.13에서 69.54로 증가하였고 $redness(a^*)$는 26.70에서 5.40으로 감소하였다. 특히 $L^*-$과 $a^*-$값 모두 $40{\sim}60^{\circ}C$에서 약 78%의 가장 큰 변화를 보였다.

• 대한핵의학회지
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• 제10권1호
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• pp.1-14
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• 1976

The etiologic role of renin-angiotensin system and sodium-volume status in the pathophysiology of various forms of hypertension was investigated. Plasma renin activity (PRA) was measured by radioimmunoassay, while sodium-volume status was evaluated by the determination of total exchangeable sodium(NaE) using isotope dilution method. The subjects consisted of 25 controls, 24 patients with essential hypertension, with chronic renal failure (13 with hypertension, 9 without hypertension) and with malignant hypertension. The results were as follows: 1. An inverse correlation between NaE and PRA was noted in control subjects (r=-0.598, p<0.001) and normal renin essential hypertension(r=-0.551, p<0.05) and the chronic renal failure with hypertension. (r=-0.790, p<0.001) 2. NaE increased markedly the in chronic renal failure with hypertension ($66.9{\pm}8.69mEq/kg$ of LBM, p<0.001) and the chronic renal failure without hypertension ($54.9{\pm}9.28mEq/kg$ of LBM, p<0.05), while mild increase was noted in malignant hypertension ($51.7{\pm}6.24mEq/kg$ of LBM, 0.05$50.1{\pm}7.24mEq$) as well as in its renin subgroups.(p>0.1) 3. Absolute value of PRA was not deviated significantly from control group ($2.53{\pm}1.416ng/ml/hr$) except in malignant hypertension ($6.09{\pm}2.042$, p<0.001). But PRA was inappropriately high in relation to prevailing NaE in the chronic renal failure with hypertension (eleven of thirteen patients) and malignant hypertension (ten of fourteen patients), while PRA variatiation was within physiologic range in the chronic renal failure without hypertension. 4. The NaE-PRA product was markedly increased in the chronic renal failure with hypertension ($514.4{\pm}42.10$, p<0.001) and in malignant hypertension ($442.7{\pm}55.03$, p<0.001), while moderately increased NaE-PRA product was noted in the chronic renal failure without hypertension ($402.6{\pm}59.67$, p<0.001). No significant difference in NaE-PRA product was noted in essential hypertension ($354.4{\pm}62.38$, p>0.1). It is suggested that renin-angiotensin system plays a predominant role in the pathogenesis of malignant hypertension and in hypertension of chronic renal failure, though sodium retention is also contributing factor. PRA variation in essential hypertension does not appear to be associated with any consistent change in Na-volume status, suggesting the existence of another mechanism in the genesis of hypertension and PRA variation.

• 한국식품과학회지
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• 제35권2호
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• pp.206-210
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• 2003

DFD육의 가공적성과 NaCl 농도에 따른 batter의 이화학적 변화를 연구하기 위하여 NaCl 농도$(0{\sim}3%)$를 다르게 하여 DFD육 batter와 정상육 batter를 제조한 후 pH, 가열감량, 직경감소율, 단백질용해성, 유화안정성, 점도 및 경도를 조사하였다. DFD육 batter와 정상육 batter는 NaCl 농도가 0%에서 3%로 증가함에 따라 가열전 pH가 DFD육은 0.23, 정상육은 0.2 unit 감소하였으며, 가열후 batter의 pH는 정상육과 DFD육 모두 가열전에 비해 다소 증가하였다. DFD육 batter의 가열감량과 직경감소율은 정상육 batter보다 낮았으며 NaCl 농도가 증가함에 따라 감소하였다. 단백질 용해성은 DFD육과 정상육 모두 NaCl 농도가 증가함에 따라 증가하였으며 DFD육의 단백질용해성이 정상육보다 높은 것으로 나타났다. 유화안정성에 있어서 DFD육 batter는 NaCl 농도가 증가함에 따라 지방분리가 급격히 감소하였으며, 정상육 batter에 비교하여 유화안정성이 다소 우수한 것으로 평가되었다. DFD육 batter의 점도는 정상육 batter보다 높게 나타났으며 NaCl 농도가 증가함에 따라 증가하였다. 또한 DFD육 batter의 경도는 NaCl 농도가 증가함에 따라 증가하였으며, 정상육 batter보다 높았다. 본 실험의 결과를 종합해 볼 때 육제품 원료육으로서 DFD육의 이용가치는 매우 우수한 것으로 사료된다.

• Journal of Microbiology
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• 제33권2호
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• pp.120-125
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• 1995

.betha.-galactosidase activity of Escherichia coli cells containing operon fusion nhaA'-'lacZ was monitored to study the regulation of expression of nhaA gene under various conditions. The expression of the fusion was enhanced only by chemicals containing Na$^{+}$ or Li$^{+}$. This Na$^{+}$ or Li$^{+}$. This Na$^{+}$(Li$^{+}$)-specific enhancement of .betha.-galactosidase activity represented the increase in the rate of synthesis of .betha.-galactosidase rather than the decrease in the breakdown rate. The induction pattern was influenced by copy numbers of the gene. Induction by Na$^{+}$ or Li$^{+}$ was concentration and time dependent, reaching maximum 5-6 fold induction after 2 hours at 0.4-0.5 M for Na$^{+}$ or at 0.25-0.35 M for Li$^{+}$, Although the expression was induced at much lower concentration of Na$^{+}$ at alkaline pH values than at neutral pH in the presence of Na$^{+}$, alkaline pH itself did ot induced the expression of the fusion in the absence of Na$^{+}$. Temperature shift and growth phase of culture did not affect the level of induction.he level of induction.

• 대한한의학회지
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• 제16권1호통권29호
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• pp.281-294
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• 1995

The effect of Sam Hwa San on the Na-K-ATPase activity was evaluated in microsomal fraction prepared from rabbit cerebral cortex to determine whether Sam Hwa San affects Na-K-ATPase activity of nervous system. Sam Hwa San markedly inhibited the Na-K-ATPase activity in a dose-dependent manner with an estimated $I_{50}$ of 0.12%. Optimal pH for the Na-K-ATPase activity was at 7.5 in the presence or absence of Sam Hwa San. The degree of inhibition by the drug more increased at acidic and alkalic pHs than neutral pH. Kinetic studies of substrate and cationic activation of the enzyme indicate classic noncompetitive inhibition fashion for ATP, Na and K, showing significant reduction in Vmax without a change in Km. Dithiothreitol, a sulfhydryl reducing reagent, partially protects the inhibition of Na-K-ATPase activity by Sam Hwa San. Combination of Sam Hwa San and ouabain showed higher inhibition than cumulative inhibition. These results suggest that Sam Hwa San inhibits Na-K-ATPase activity in central nervous system by reacting with, at least a part, sulfhydryl group and ouabain binding site of the enzyme protein, but with different binding site from those of ATP, Na and K.

• 한국환경과학회지
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• 제13권12호
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• pp.1015-1021
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• 2004

This study was conducted to investigate the changes of chlorophyll contents and chlorophyll fluorescence in barley(Hordeum vulgare L.) 7 day old seedling treated with 0.2M, 0.4M, 0.6M, 0.8M, and 1.0M NaCI concentration containing Hepes buffer(pH 7.5). Barley was affected by NaCI treatment. The chlorophyll a, b and carotenoid of barley decreased with an increase in NaCI concentration. However, chlorophyll a, b and carotenoid of barley were not greatly influenced by o.8M and 1.0M NaCl. Fv, Fv/Fm and qP were gradually decreased by higher concentration of NaCI. qP, qNP, qR and qE were gradually decreased by 6hr. During barley chloroplast was development NaCI affected chlorophyll synthesis than photosynthetic activity. Whereas barley seedling leaves were more influenced photosynthetic activity than chlorophyll contents by NaCI.

• 한국식품조리과학회지
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• 제5권2호
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• pp.9-17
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• 1989

This study was carried out in order to study the emulsifying properties of kidney bean protein isolate. Kidney bean protein isolate was tested for the purpose of finding out the effect of pH, addition of NaCl, and heat treatment on the solbulity and emulsion capacity, emulsion stability, surface hydropobicity and emulsion viscosity. The results were summarized as follows. 1 The solubility of kidney bean protein isolate was affected by pH and showed the lowest value at pll 4.5 which is isoelectric point of kidney bean isolate. When the kidney bean protein isolate was heated, the highest value observed at pH 2 and pH 7 was 96.11%, 97.41% respectively. 2. The emulsion capacity of kidney bean protein isolate was not significantly different with each pH. With addition of NaCl, emulsion capacity decreased steadily. When heated thr highest value observed at pH 2 and pH 7 was 82.91 ml oil/100 mg protein ($60^{\circ}C$), 82.08 m1 oil/100 mg protein ($80^{\circ}C$) respectively. 3. The emulsion stability was significantly higher at pH 4.5 than that of pH 2 and pH 7 (p 0.05) When NaCl was added, emulsion stability was generally increased after 2hrs. When heated, the highest value observed at pH 2 and pH 7 was 21.25% ($80^{\circ}C$),23.7%($100^{\circ}C$) respectively after 2hrs. 4. Surface hydrophobicity increased sharply as 0.2 M NaCl was added to pH 4.5. When heated, the surface hydrophobicity increased as the temperature increased. 5. The highest value of emulsion viscosity was observed at pH 4.5 and pH 7 when 0.2 M NaCl was added. Under heat treatment, the highest value was 48,000 cps at pH 4.5 ($40^{\circ}C$). In the case of pH 7, the highest value was 105,000 cpa at $100^{\circ}C$.

• 한국방사선학회논문지
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• 제7권1호
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• pp.85-91
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• 2013

감마선이 조사된 세포막 모델에서 $K^+$ 와 $Na^+$의 선택적 전달특성을 연구하였다. 이 실험에 사용된 세포막 모델은 $Na^+$ 슬폰화 폴리스티렌-디비닐벤젠(polystyrene-divinylbenzene) 혼성 중합막을 사용하였다. 이온의 초기플럭스는 $H^+$ 이온 농도의 증가와 함께 증가하였다. 이 실험의 조건을 pH 0.5-3, 온도 $15-65^{\circ}C$로 하여 첫 번째 조사되지 않은 막의 $K^+$와 $K^+/Na^+$의 선택도는 약 1.06 - 1.13이고 두 번째 조사된 막의 $K^+$와 $K^+/Na^+$의 선택도는 약 0에 가깝다. 조사된 막의 pH의 추진력은 조사되지 않은 막보다 약 4-5배 정도 유의성 있게 증가하였다. 세포막모델에서 $K^+$와 $Na^+$의 선택적 전달특성이 비정상적이기 때문에 세포장해가 세포에서 발현된다.

• Animal Bioscience
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• 제37권2호
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• pp.240-252
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• 2024

Objective: The aim of this study was to investigate the impact of dietary nicotinic acid (NA) on apparent nutrient digestibility, rumen fermentation, and rumen microbiota in uncastrated Xiangzhong black cattle. Methods: Twenty-one uncastrated Xiangzhong black cattle (385.08±15.20 kg) aged 1.5 years were randomly assigned to the control group (CL, 0 mg/kg NA in concentrate diet), NA1 group (800 mg/kg NA in concentrate diet) and NA2 group (1,200 mg/kg NA in concentrate diet). All animals were fed a 60% concentrate diet and 40% dried rice straw for a 120-day feeding experiment. Results: Supplemental NA not only enhanced the apparent nutrient digestibility of acid detergent fiber (p<0.01), but also elevated the rumen acetate and total volatile fatty acid concentrations (p<0.05). 16S rRNA gene sequencing analysis of rumen microbiota revealed that dietary NA changed the diversity of rumen microbiota (p<0.05) and the abundance of bacterial taxa in the rumen. The relative abundances of eight Erysipelotrichales taxa, five Ruminococcaceae taxa, and five Sphaerochaetales taxa were decreased by dietary NA (p<0.05). However, the relative abundances of two taxa belonging to Roseburia faecis were increased by supplemental 800 mg/kg NA, and the abundances of seven Prevotella taxa, three Paraprevotellaceae taxa, three Bifidobacteriaceae taxa, and two operational taxonomic units annotated to Fibrobacter succinogenes were increased by 1,200 mg/kg NA in diets. Furthermore, the correlation analysis found significant correlations between the concentrations of volatile fatty acids in the rumen and the abundances of bacterial taxa, especially Prevotella. Conclusion: The results from this study suggest that dietary NA plays an important role in regulating apparent digestibility of acid detergent fiber, acetate, total volatile fatty acid concentrations, and the composition of rumen microbiota.