Amounts Of Glutamic Acid Research Articles

Removal of Aluminum from Synthetic Rare Earth Leach Solution by Selective Complexation and Turbidity Point Extraction

During the leaching process of ion-adsorbed rare earth ores, large amounts of non-rare earth impurities such as aluminum and iron will be generated. This study selected glutamic acid as a complex agent to selectively calculate aluminum ions; then, added non-ionic surfactants and extract and separate aluminum ions from a rare earth solution using the cloud point extraction method. The effects of solution pH, reaction temperature, equilibration time, amount of glutamic acid, reaction time, and amount of Triton X-114 on aluminum extraction were investigated. The results showed that with a Mglu:MAl ratio of 3:1, a solution pH of 4.5, a constant temperature of 40 °C, and the addition of 10 mL Triton X-114 after 10 min of reaction time, the single extraction efficiency of aluminum ions reached 78.01%, and the extraction efficiency of rare earths was only 5.09% after 10 min of equilibration time. The reaction equation of glutamic acid with aluminum ions was determined, and the lowest extraction concentration of aluminum ions in the glutamic acid complexation extraction solution was found to be cAl = 0.045 ± 0.003 g/L, with a separation coefficient of β(Al/RE) = 66.15. This result indicated that the aluminum ions in the mixed solution could be effectively separated from the rare earth ions when using glutamic acid as a complexing agent in combination with the turbidity point extraction method.

Incorporation of Glutamic Acid or Amino-Protected Glutamic Acid into Poly(Glycerol Sebacate): Synthesis and Characterization.

Poly(glycerol sebacate) (PGS), a soft, tough elastomer with excellent biocompatibility, has been exploited successfully in many tissue engineering applications. Although tunable to some extent, the rapid in vivo degradation kinetics of PGS is not compatible with the healing rate of some tissues. The incorporation of L-glutamic acid into a PGS network with an aim to retard the degradation rate of PGS through the formation of peptide bonds was conducted in this study. A series of poly(glycerol sebacate glutamate) (PGSE) containing various molar ratios of sebacic acid/L-glutamic acid were synthesized. Two kinds of amino-protected glutamic acids, Boc-L-glutamic acid and Z-L-glutamic acid were used to prepare controls that consist of no peptide bonds, denoted as PGSE-B and PGSE-Z, respectively. The prepolymers were characterized using 1H-NMR spectroscopy. Cured elastomers were characterized using FT-IR, DSC, TGA, mechanical testing, and contact angle measurement. In vitro enzymatic degradation of PGSE over a period of 28 days was investigated. FT-IR spectroscopy confirmed the formation of peptide bonds. The glass transition temperature for the elastomer was found to increase as the ratio of sebacic acid/glutamic acid was increased to four. The decomposition temperature of the elastomer decreased as the amount of glutamic acid was increased. PGSE exhibited less stiffness and larger elongation at break as the ratio of sebacic acid/glutamic acid was decreased. Notably, PGSE-Z was stiffer and had smaller elongation at break than PGSE and PGSE-B at the same molar ratio of monomers. The results of in vitro enzymatic degradation demonstrated that PGSE has a lower degradation rate than does PGS, whereas PGSE-B and PGSE-Z degrade at a greater rate than does PGS. SEM images suggest that the degradation of these crosslinked elastomers is due to surface erosion. The cytocompatibility of PGSE was considered acceptable although slightly lower than that of PGS. The altered mechanical properties and retarded degradation kinetics for PGSE reflect the influence of peptide bonds formed by the introduction of L-glutamic acid. PGSE displaying a lower degradation rate compared to that for PGS can be used as a scaffold material for the repair or regeneration of tissues that are featured by a low healing rate.

A Comparative Study on the Taste Characteristics of Satellite Cell Cultured Meat Derived from Chicken and Cattle Muscles.

This study investigated the amino acid and nucleotide-related compound composition and taste characteristics of cultured muscle tissue (CMT) obtained by culturing satellite cells isolated from chicken and cattle and compared them to those of traditional meat (TM). The content of all amino acids except valine and tyrosine was significantly different between CMT and TM (p<0.05). The amount of glutamic acid was not significantly different between CMT and TM in cattle, but the glutamic acid in chicken CMT was lower than that of TM (p<0.05). Among the nucleotide-related compounds, only the content of inosine-5'-monophosphate (IMP) was significant, and the amount of IMP in CMT derived from chicken and cattle was significantly lower than that of TM (p<0.05). There were significant differences in the taste characteristics assessed by an electronic tongue system, and the umami, bitterness, and sourness values of CMT were significantly lower than those of TM from both chicken and cattle (p<0.05). The results of the present study suggest that it is necessary to develop a satellite cell culture method that could increase the umami and bitterness intensity of CMT and adjust the composition of the growth medium to produce cultured meat with a taste similar to that of TM.

Comparison of nutritional composition, chemical preservative, and glutamic acid content of canned food with freshly cooked and home-cooked food products

Thermal preservation using the canning method is a promising alternative for retaining the maximum quality of the foods. Recently, the rising awareness of the nutritional value of canned products has received the attention of various researchers, as canned food can offer both healthy and convenient solutions to consumers. The present study reported the nutritional values and presence of food additives and preservatives in different Ayam BrandTM canned foods in tomato sauce namely sardines (CS), mackerel (CM) and baked beans (CB), canned tuna flakes in water (CTF) and canned tuna in mayonnaise (CTM) compared to the fresh and home-cooked food samples. The canned products, CS and CM contain significantly higher (p&lt;0.05) amounts of Omega-3 but are lower in protein compared to their fresh counterparts. The calcium compositions of canned sardines and mackerels are 10-fold higher than fresh and home-cooked, contributed by the soft and brittles bones which enriched with calcium. The nutritional values of canned products were maintained throughout the storage period throughout the span of 3 years, with insignificant changes (p&gt;0.05). Regardless of canned or fresh food samples, there was no total dietary fiber, benzoic acid, sorbic acid and sulfur dioxide detected in all samples except for the dietary fiber in the baked beans. CS and CTM contained significantly (p&lt;0.05) higher amounts of glutamic acid than their fresh counterparts and the glutamic acid in all canned products ranging from 0.001-0.37 mg/g which is within the acceptable daily intake of 13 g/day. The natural glutamic acid was contributed by the raw materials of fish and tomato sauces themselves. No MSG was detected in all canned products. Therefore, it is safe to consume canned food products that greatly representing fresh and home-cooked foods without compromising with the nutritional values

Alterations in some physiological processes of Bactrocera oleae Rossi (Diptera: Tephritidae) following pyridalyl treatment

Pyridalyl is one of the recently discovered insecticides which has shown toxicity against several insect pests with slight- or non-lethal effects against natural enemies. Cytotoxicity and prevention of protein synthesis have been reported as pyridalyl mode of action. In the current study, adults of Bacterocera oleae, as a major pest of olive, were fed on protein hydrolysate diet containing LC50 concentration of pyridalyl to determine the possible mode of action through gene expression and amino acid profile. Results showed that treated flies had significantly higher gene expressions of cytochrome P450, insulin receptor-like, antioxidant enzymes (catalase, peroxidase, superoxide dismutase) and the enzymes involved in cell death; caspase1, caspase3, caspase8 and caspase9 compared to control. Moreover, determination of amino acid profile in the whole body of both control and pyridalyl-treated B. oleae revealed the significant higher amounts of glutamic acid, glutamine, histidine, threonine, citrulin, arginine, taurine, alanine, tyrosine, α-amino butric acid, methionine and isoleucine in the treated adults while the control flies had the higher amounts of serine, glycine and tryptophane. No significant differences were found in the amounts of asparagine and phenylalanine between control and treatments. These results are in accordance with earlier findings on mode of action of pyridalyl through activation of cytochrome P450 system and alterations in protein synthesis machinery although here other mechanisms were also reported including activation of insulin receptor and antioxidant enzymes. Moreover, it is the first report on cytotoxicity through apoptosis with engagement of caspases.

Glutamic Acid as an Efficient and Green Catalyst for the One-Pot Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles under Thermal, Solvent-Free Conditions

A high-yielding synthesis of 1,2,4,5-tetrasubstituted imidazoles is described, involving the reaction of 1,2-dicarbonyl compounds, aryl aldehydes, amines and ammonium acetate in the presence of a catalytic amount of glutamic acid under thermal, solvent-free conditions. The salient features of this protocol are aerobic conditions, a non-hazardous green catalyst, short reaction times and mild reaction conditions.

Effects of deep-frying to sardine croquettes’ chemical composition

Fish croquettes were produced with sardine meat and effects of deep-frying on chemical composition of the products were determined in this study. The crude fat and ash increased in the sardine croquettes while water and crude protein decreased with frying process (P<0.05). Amino acid analyses showed that amount of glutamic acid, lysine and leucine were the highest ones respectively. The amount of leucine, isoleucine, lysine, phenylalanine and threonine decreased while the amount of the methionine remained in the same level statistically after deep-frying. The essential amino acids for human expect tryptophan were specified in sardine meat and croquettes. Total of saturated fatty acids in sardine meat decreased associated with increasing of unsaturated fatty acids during the croquette production and deep-frying process. Polyunsaturated fatty acids such as docosahexaenoic acid, eicosapentaenoic acid and linoleic acid were detected in all groups. Considering the elemental composition of the final product after deep-frying, this research study indicates that deep-frying does not effect a number of trace elements. Also, toxic elements for human health were not detected in any products.

Nutritional value and proteases of Lentinus citrinus produced by solid state fermentation of lignocellulosic waste from tropical region.

This paper examined the growth and yield performance of Lentinus citrinus on cupuaçu exocarp (Theobroma grandiflorum) mixed with litter (CE + LI) or rice bran (Oryza sativa) (CE + RB) in the ratio of 2:1 (800 g:200 g) to investigate the nutritional composition and proteolytic potential of the fruiting body produced. Significance values of yield were determined on substrate combinations. In CE + LI the biological efficiency of the mushrooms was 93.5% and the content of fat (4.5%), fiber (11.0%), protein (27.0%) and amino acids were higher when compared with CE + RB. Among the amino acids, the amount of glutamic acid, aspartic acid, alanine, arginine and leucine was high. The biological efficiency on CE + RB reduced to 84.2% and based on the nutritional value, carbohydrates (53.59%), energy (324.33 kcal) and minerals such as zinc, iron, copper, potassium and phosphorus were higher in this substrate combination. Protease activity from fruiting body was significant in CE + LI (463.55 U/mL). This protease showed an optimal activity at 50 °C in neutral and alkaline pH with maximum stability at 30 °C at alkaline pH. This is the first report of L. citrinus fruiting body nutritional composition with potential for human food and application in industrial processes.

PGC-1α-Mediated Branched-Chain Amino Acid Metabolism in the Skeletal Muscle

Peroxisome proliferator-activated receptor (PPAR) γ coactivator 1α (PGC-1α) is a coactivator of various nuclear receptors and other transcription factors, which is involved in the regulation of energy metabolism, thermogenesis, and other biological processes that control phenotypic characteristics of various organ systems including skeletal muscle. PGC-1α in skeletal muscle is considered to be involved in contractile protein function, mitochondrial function, metabolic regulation, intracellular signaling, and transcriptional responses. Branched-chain amino acid (BCAA) metabolism mainly occurs in skeletal muscle mitochondria, and enzymes related to BCAA metabolism are increased by exercise. Using murine skeletal muscle overexpressing PGC-1α and cultured cells, we investigated whether PGC-1α stimulates BCAA metabolism by increasing the expression of enzymes involved in BCAA metabolism. Transgenic mice overexpressing PGC-1α specifically in the skeletal muscle had increased the expression of branched-chain aminotransferase (BCAT) 2, branched-chain α-keto acid dehydrogenase (BCKDH), which catabolize BCAA. The expression of BCKDH kinase (BCKDK), which phosphorylates BCKDH and suppresses its enzymatic activity, was unchanged. The amount of BCAA in the skeletal muscle was significantly decreased in the transgenic mice compared with that in the wild-type mice. The amount of glutamic acid, a metabolite of BCAA catabolism, was increased in the transgenic mice, suggesting the activation of muscle BCAA metabolism by PGC-1α. In C2C12 cells, the overexpression of PGC-1α significantly increased the expression of BCAT2 and BCKDH but not BCKDK. Thus, PGC-1α in the skeletal muscle is considered to significantly contribute to BCAA metabolism.

Orbital Frontal Cortex D1 Dopamine Receptor Modulate Glutamate and NMDA Receptor in Depression Induced by Chronic Unpredictable Mild Stress

Stressors play a pivotal role in the occurrence of depressive illnesses. Disorders of monoamine neurotransmitters and their receptors may be the fundamental causes of depression. Additionally, abnormal expression of glutamic acid(Glu) and its receptor may be a major reason for depression. Consequently, the study of the relationship between monoamine and glutamic acid neurotransmitter in stress-induced depression has significances to reveal the profound mechanism of depression. NR2B subunits which are highly expressed in the cortex, hippocampus and olfactory bulb, are one of the key subunits of NMDA receptors. Orbital frontal cortex(orbital frontal cortex, OFC), which plays a significant role in higher brain function, such as emotional and complex behavior, is one of the major sub-regions of prefrontal. This study was to investigate the effect of orbital frontal cortex D1 dopamine receptor on Glu and its receptors, especially on NR2B subunits of N-methyl-D-aspartic acid(NMDA) receptors in depression induced by chronic unpredictable mild stress(CUMS). CUMS-induced depression model was established in Sprague-Dawley rats, and intra-orbital frontal cortex microinjections of D1 dopamine receptor agonist SKF38393 and its antagonist SCH23390 were respectively adopted by rat brain stereotaxic coordinates. The behavioral observations were conducted by measurement of sucrose preference test, open-field test and tail suspension test. The concentration of Glu and the expression ofNR2B subunits in orbital frontal cortex were detected by high-performance liquid chromatography(HPLC) and Western blot(WB) respectively. In comparison to control groups, depression-like behavioral changes were observed in CUMS rats, the concentration of dopamine and its D1 receptor were decreased; conversely, the increase of Glu and NR2B subunits of its NMDA receptors were observed in orbital frontal cortex. Depression-like behavioral of CUMS rats was obviously improved after pretreatment with injection of SKF38393, the expression of Glu and NR2B subunits of its NMDA receptors were also decreased. Normal rats showed depression-like behavioral which similar to the CUMS rats after pretreatment with injection of D1 dopamine receptor antagonist SCH23390, meanwhile, in orbital frontal cortex the expression of Glu and NR2B subunits of its NMDA receptors were significantly increased. These results suggest that the lowered dopamine release may be caused by chronic unpredictable mild stress, as the result of insufficient dopamine, orbital frontal cortex releases extra amounts of glutamic acid and its NMDA receptors are over activated. All those above then may lead to depression. Antidepressant effect of dopamine may be functioned by inhibiting the expression of Glu and NR2B subunits of its NMDA receptors.

Biochemical change of fermented scallop (Argopecten irradians Lamarck) flour paste in different fermentation periods

The aim of this paper was to study the biochemical changes in fermented scallop flour paste (SFP) during different fermentation periods. SFP was prepared with scallop muscles, flour koji, salt, rice koji, and neutral protease at 40°C for 12 days. Biochemical changes during fermentation were investigated. By reducing sugar content, formaldehyde nitrogen content, total acid content, and free amino acids (FAAs), the concentration of SFP was increased but water activity was decreased. Most FAAs were increased, and the amounts of glutamic acid, glycine, alanine, and leucine were high. Some amino acid concentrations were higher than their taste threshold, such as the glutamate of umami, the glycine and alanine of sweet and umami, and the arginine and lysine of bitter and sweet. They contributed significantly to the characteristic taste of SFP. Therefore, SFP is a potential seasoning agent with nutritional properties and good taste.

A simple automated system for measuring soil respiration by gas chromatography

An automated dynamic closed chamber system for CO(2) sampling and analysis was developed for the measurement of soil respiration under laboratory conditions. The system is composed by a gas chromatograph linked to a fully computerised sampling system composed by 16 sample jars and 2 multiposition valves. Besides CO(2), the system can automatically and simultaneously measure CH(4), N(2)O and other gases of environmental interest. The detection limits of the system for CO(2), N(2)O and CH(4) were 2, 1 and 4ppmv, respectively. The accuracy of the system, expressed as percent bias, was -0.88, -0.94 and -3.17% for CO(2), N(2)O and CH(4), respectively, with relative standard deviation of 0.42, 0.68 and 0.61%. Measurement of CO(2) evolved following acidification of a known amount of reagent grade CaCO(3) showed a standard recovery of 96.8+/-2.5% reached within 30s after acidification. A linear response of CO(2) respiration was obtained for a wide range of operative conditions (5-60min accumulation time, 10-80g soil sample size, 10-60mLmin(-1) air flow rate, 15-25 degrees C temperature of incubation) demonstrating the flexibility of the system, which allows for the measurement of soil samples characterised by different rates of gas evolution. Moreover, the results obtained with soil samples showed that within the above conditions the proposed system is not affected by potential limitations of static closed chamber systems such as CO(2) dissolution in the soil solution, reduced rate of CO(2) diffusion from soil to headspace and CO(2) inhibition of microbial activity. The system was also capable to detect significant changes in N(2)O emissions from soil amended with different amounts of glutamic acid. The automatic and frequent measurements provided by the system make possible an accurate description of the dynamics of gas evolution from soil samples under laboratory conditions.

Optimization of Corynebacterium glutamicum Glutamic Acid Production by Response Surface Methodology

Response surface methodology (RSM) was used to evaluate the effects of fermentation parameters for glutamic acid (GA) production by Corynebacterium glutamicum CECT690 in submerged fermentation using palm date waste as substrate. To attain this purpose at the first stage, inoculum size, substrate concentration, penicillin concentration, phosphate concentration, and inoculum age were optimized for GA production. The next stage, the level of air flow rate in a 5-l fermenter (batch mode) which was run in optimized conditions was determined. The first stage gave the following results for the fermentation conditions optimized using RSM in 500-ml shake flasks: inoculum size 2% (v/v), substrate concentration 25% (w/v), penicillin concentration 1 U/ml, phosphate concentration 4 g/l, and inoculum age 10 h. Moreover, the maximum GA amount predicted by the model was 39.32 mg/ml. This was in agreement with the actual experimental value (36.64 mg/ml). In the second stage of the study, the amounts of GA were 118.75, 142.25, and 95.83 mg/ml in optimized conditions with the three levels of air flow rate of 0.6, 1.2, and 1.6 vvm, respectively. The present results demonstrate the potential of date waste juice as a substrate for producing GA by cultivation of C. glutamicum.

UPTAKE AND METABOLISM OF PLASMA GLUTAMINE BY THE SMALL INTESTINE

Abstract An isolated, vascularly perfused preparation of rat intestine extracted large amounts of glutamine (75 µmoles per hour), but no other amino acid, from a recirculated blood perfusate. With l-[U-14C]glutamine, the carbon was partly incorporated into tissue acid-insoluble material (14%) and the rest reappeared with little delay in intestinal venous blood in CO2 (57%), citrulline (6%), proline (5%), and organic acids (18%), predominantly citric acid and lactic acid. Perfusate glutamine was the source of 32% of the CO2 produced by the preparation, although the perfusate contained 10 to 15 mm glucose. Most glutamine uptake and metabolism occurred in the small intestinal mucosal cells and, from analyses of labeled tissue metabolites, appeared to proceed via glutamic acid. The rapid flow of glutamine carbon through mucosa may be explained in part by the small glutamine pool, only 0.2 µmole per g of tissue. Glutamine nitrogen taken up by intestine could be approximately accounted for by the quantities of citrulline (34%), alanine (33%), ammonia (23%), and proline (10%) released back into the perfusate. Glutamine uptake comparable to that found in the isolated organ was observed in vivo, from arteriovenous concentration measurements across intestine in fasted dogs, cats, hamsters, monkeys, and conventional and germ-free rats. Twenty-five to 33% of plasma glutamine was extracted in each pass through the tissue. Glutamine uptake persisted in rats during transport of large amounts of glutamic acid from the intestinal lumen into the blood and in rats injected with 6-diazo-5-oxo-l-norleucine. The results of these studies suggest that glutamine derived from blood is an important respiratory substrate for cells in the small intestinal mucosa and that intestine is a major site for metabolism of glutamine released into the circulation by other tissues.

Development of natto with germination-defective mutants of Bacillus subtilis (natto)

The effects of cortex-lysis related genes with the pdaA, sleB, and cwlD mutations of Bacillus subtilis (natto) NAFM5 on sporulation and germination were investigated. Single or double mutations did not prevent normal sporulation, but did affect germination. Germination was severely inhibited by the double mutation of sleB and cwlD. The quality of natto made with the sleB cwlD double mutant was tested, and the amounts of glutamic acid and ammonia were very similar to those in the wild type. The possibility of industrial development of natto containing a reduced number of viable spores is presented.

Aqueous Synthesis of Ordered Mesoporous Carbon via Self-Assembly Catalyzed by Amino Acid

In this manuscript, we demonstrate a synthesis of ordered mesoporous carbon via a self-assembly of resorcinol-formaldehyde polymer and surfactant F127 in aqueous phase in the presence of glutamic acid as the catalyst. It was found that the amounts of glutamic acid and surfactant F127 in the synthesis are important in determining the structural ordering of the resultant mesoporous carbons. The textural parameters of the obtained ordered mesoporous carbon are tunable simply by varying the pyrolysis temperature. The process has the advantage of being a single step self-assembly approach and only involves the use of simple organic precursors and water.

Changes in the amounts of water-soluble umami-related substances in porcine longissimus and biceps femoris muscles during moist heat cooking

Time course changes in amounts of glutamic acid, total free amino acid, inosine monophosphate (IMP), and 2%-trichloroacetic acid-soluble oligopeptides in whole, muscle only, and cooking juice during wet–heat cooking in pork longissimus and biceps femoris muscles were investigated because the movements of umami-relevant substances during cooking treatment had not previously been clarified in detail. The amounts of glutamic acid, total free amino acid, and IMP significantly ( P < .05) decreased and increased in muscle and cooking juice during 180 min of cooking, respectively. The whole amounts of glutamic acid and total free amino acid remained unchanged during cooking treatment. The whole amount of IMP, however, increased significantly at 10 min of cooking ( P < .05) and was maintained after the 10-min period. The extramuscular oligopeptides amount increased significantly in response to the cooking treatment ( P < .05). The intramuscular amount of oligopeptides decreased at 30 min of cooking but increased significantly ( P < .05) after 60 min. The whole meat oligopeptides amount increased significantly during a 180-min cooking treatment ( P < .05). These results indicate that glutamate, total free amino acid, and IMP were released from the muscle during cooking, and that IMP levels increased in the initial phase of cooking. In addition, oligopeptides increased during wet–heat cooking of pork muscles.

Effects of the Insertion of Unilateral Extension Base Removable Partial Dentures on the Amount of an Umami Component Eluted during Mastication

Purpose: The purpose of this study was to investigate the effects of the insertion of unilateral extension base removable partial dentures (RPDs) on the elution of umami components during mastication in Kennedy Class II cases.Methods: Rishiri kelp cut into 25 mm×25 mm pieces was selected as the test food. Eight patients with unilateral molar teeth defects were instructed to masticate samples for 50 strokes each, on the edentate side with RPDs, on the edentate side without RPDs, and on the dentate side. The amount of glutamic acid extracted from the samples was determined by spectrometry; the difference between the amounts of glutamic acid in the original and chewed samples was regarded as the amount intraorally eluted. The ratios of the amounts of glutamic acid eluted intraorally to that present in the original samples were compared among the groups.Results: Bonferroni-adjusted Wilcoxon matched-pairs signed-rank tests revealed a significant difference between the ratios of the amount of glutamic acid eluted intraorally from samples chewed on the edentate side with RPDs and that from samples chewed on the edentate side without RPDs and between the ratios of the amount of glutamic acid eluted intraorally from samples chewed on the dentate side and that from samples chewed on the edentate side without RPDs (P<0.017). There was no significant difference between the ratios of the amount of glutamic acid eluted intraorally from samples chewed on the edentate side with RPDs and that from samples chewed on the dentate side (P=0.48).Conclusion: Our results suggested that the insertion of unilateral extension base RPDs were useful for the elution of umami components during mastication.

홍조류의 영양 성분과 항산화 활성

갈래곰보(Meristotheca papulosa (Montagne) Kylin), 진두발 (Chondrus ocellatus, Holmes), 꼬시래기(Gracilaria verrucosa (Hudson) Papenfuss) 및 돌가사리(Gigartina tenella, Harvey) 를 대상으로 영양성분을 분석하고, 에탄을 추출물의 항산화 및 아질산염 소거 활성을 실험함으로서 그 기능성을 규명하고자 하였다. 회분의 함량은 시료간의 차가 커 꼬시래기의 경우 <TEX>$9.8{\pm}0.2g/100g$</TEX>이었으나 돌가사리는 <TEX>$17.8{\pm}0.6g/100g$</TEX>으로 가장 높은 함량이었다. 조섬유의 함량은 <TEX>$2.0{\pm}0.4{\sim}6.0{\pm}0.7\;g/100g$</TEX>의 범위였다. 페놀화합물은 꼬시래기에서 <TEX>$78.4{\pm}1.0mg/g$</TEX>으로 가장 높은 함량이었으며, 총 플라보노이드의 함량은 진두발과 꼬시래기에서 각각 <TEX>$14.9{\pm}0.5mg/g$</TEX>과 <TEX>$13.9{\pm}0.8mg/g$</TEX>으로 정량되어 갈래곰보와 돌가사리에 비해 약 2배 정도 더 높은 함량이었다. 무기물의 총 함량은 갈래곰보에서 12,107.7 mg/kg으로 가장 높았다. 구성 아미노산은 <TEX>$49.1{\sim}125.6mg/g$</TEX>으로 시료에 따른 함량 차가 켰으며 대부분의 시료에서 glutamic acid의 함량이 가장 높게 정량되었다. SOD 유사활성은 시료의 농도가 증가함에 따라 유의적으로 증가하는 경향을 나타내었으나 전체적인 활성은 낮았다. 전자공여능이 가장 높은 돌가사리의 경우 <TEX>$250{\mu}g/ml$</TEX>농도에서 <TEX>$53.96{\pm}0.98%$</TEX>로 50% 이상의 활성을 보였으며 1000 <TEX>${\mu}g/ml$</TEX>농도에서는 <TEX>$70.52{\pm}1.09%$</TEX>로 그 활성이 증가하였다. 100 <TEX>${\mu}g/ml$</TEX>의 농도에서는 시료들의 hydroxy radical 소거활성은 <TEX>$57.87{\pm}1.70{\sim}62.07{\pm}0.87%$</TEX>의 범위로 ascorbic acid나 BHT에 비해 유의적으로 높은 활성을 나타내었다. 아질산염 소거능은 꼬시래기에서 가장 높았는데 <TEX>$100{\sim}500{\mu}g/ml$</TEX> 농도에서는 <TEX>$24.04{\pm}1.9{\sim}27.52{\pm}0.82%$</TEX>의 범위였으나 1000 <TEX>${\mu}g/ml$</TEX> 농도에서는 <TEX>$34.81{\pm}1.36%$</TEX>로 증가하였다. 이상의 항산화 활성을 평가한 결과 본 실험에 사용된 홍조류 4종은 전자공여능과 hydroxy radical 소거활성이 우수하였다. Nutritional components of 4 kinds of red seaweeds, Meristotheca papulosa, Chondrus ocellatus, Gracilaria verrucosa, Gigartina tenella, were investigated to elucidate their functionality. Antioxidant activity and nitrite scavenging activity were analyzed from 70% ethanol extracted from these red seaweeds. Large difference in ash contents was found to exhibit among all samples analyzed in this study; <TEX>$9.8{\pm}0.2g/100g$</TEX> for Gracilaria verrucosa and Gigartina tenella for <TEX>$17.8{\pm}0.6g/100g$</TEX>. While its crude fiber content was almost the same as those in other sample within a range between <TEX>$2.0{\pm}0.4g/100g$</TEX> and <TEX>$6.0{\pm}0.7g/100g$</TEX>. Phenolic compounds content of Gracilaria verrucosa was also the highest as <TEX>$78.4{\pm}1.0mg/g$</TEX>, while the total flavonoids contents of Chondrus ocellatus and Gracilaria verrucosa were <TEX>$14.9{\pm}0.5mg/g$</TEX> and <TEX>$13.9{\pm}0.8mg/g$</TEX>, respectively. These amounts were two folds higher than Meristotheca papulosa and Gigartina tenella. The total content of minerals was the highest in Meristotheca papulosa(12,107.7 mg/kg). The amount of glutamic acid was relatively high despite of small variation in measured levels of composition amino acid (<TEX>$49.1{\sim}125.6mg/g$</TEX>) for most samples investigated. SOD-like ability was significantly increased with increasing sample concentration, but its activity was lower. Gigartina tenella with highest electron donation ability exhibited increases in activity as <TEX>$53.96{\pm}0.98%$</TEX> in concentration of 250 <TEX>${\mu}g/ml$</TEX> and <TEX>$70.52{\pm}1.09%$</TEX> in 1000 <TEX>${\mu}g/ml$</TEX>, respectively. In case of concentration of 100 <TEX>${\mu}g/ml$</TEX>, particularly, the level of hydroxy radical scavenging activity were <TEX>$57.87{\pm}1.70{\sim}62.07{\pm}0.87%$</TEX> which was significantly higher activity than ascorbic acid and BHT. Nitrite scavenging activity was the highest in Gracilaria verrucosa. Its activity was also increased from <TEX>$24.04{\pm}1.9{\sim}27.52{\pm}0.82%$</TEX> in <TEX>$100{\sim}500{\mu}g/ml$</TEX> concentration tp <TEX>$34.81{\pm}1.36%$</TEX> in concentration of 1000 <TEX>${\mu}g/ml$</TEX>.

Determination of glutamic acid by an oscillating chemical reaction using the analyte pulse perturbation technique

An analytical method for the determination of glutamic acid by the sequential perturbation caused by different amounts of glutamic acid on the oscillating chemical system involving the Cu(II)-catalyzed oscillating reaction between hydrogen peroxide and sodium thiocyanate in an alkaline medium is proposed. The method relies on the linear relationship between the changes in the oscillation amplitude of the chemical system and the concentration of glutamic acid. The reaction is implemented in a continuous-flow stirred-tank reactor, and changes in the oscillation amplitude on each perturbation are proportional to the glutamic acid concentration. The use of the analyte pulse perturbation (APP) technique permits sequential determinations on the same oscillating system owing to the expeditiousness with which the steady state is regained after each perturbation. The dynamic range lies between 2.5×10 −6 and 3.2×10 −4 M of glutamic acid, with the regression coefficient is 0.9987. The precision is excellent (less than 0.68% as relative standard deviation (R.S.D.)). Some aspects of the potential mechanism of action of glutamic acid on the oscillating system are discussed.