• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.4
• /
• pp.394-402
• /
• 2001

In order to investigate the composition of dried layer, Porphyra yezoensis cultured at the south coast of Korea, the dried laver was analyzed separately for extractive nitrogen, free and combined amino acids, ATP and related compounds and quaternary ammonium basis using specimens collected monthly from January to April 1998. The extractive nitrogen contents of dried layer extracts were $976\~1,196\;mg/100\;g$ (on dry basis). Twenty-eight to thirty-one kinds of free amino acids were found in the dried laver extracts and their total amounts were 5,648-6,845 mg/100 g (on dry basis). The extracts were rich in free amino acids such as alanine, glutamic acid, taurine, phosphoserine and aspartic acid. Eighteen to twenty-two kinds of combined amino acids from oligopeptides were found in the extracts and their total amounts were $1,194\~1,406\;mg/100\;g$ (on dry basis). The amounts of ATP and related compounds were $111.6\~195.5\;mg/100\;g\;(3.30\~6.00{\mu}mol/g$ on dry basis). Homarine was detected in all samples but glycinebetaine, $\beta$-alaninebetaine and $\gamma$-butyrobetaine disappeared during processing, TMAO was detected in all samples but low TMA was found in some. During processing of dried layer, P. yezoensis, free amino acids, ATP and its related compounds were increased but the other constituents such as combined amino acids, TMAO and TMA and betaines were decreased in all specimens.

• Korean Journal of Food Science and Technology
• /
• v.13 no.2
• /
• pp.121-126
• /
• 1981

An adenine-guanine doubless and $\beta$-alanine requiring mutant, D-1550-40, which had been derived from Brevibacterium ammoniagenes ATCC 6872, produced a copious amount of xanthosine-5'-monophosphate (XMP). The optimum concentration of adenine and guanine for maximal accumulation of XMP was about 75 ml/l and 100 ml/l for growth. Concentrations higher than 100 mg/l of adenine and guanine inhibited cell growth and XMP accumulation strongly. The inhibition, however, could be recovered by adding $100{\mu}g$ of biotin per liter or 0.3% of casamino acids to the culture solution. High concentrations of phosphate and magnesium salts (1.0 to 1.5%(w/v) in media) were found to be indispensable for XMP accumulation, and the presence of manganese in the culture medium stimulated both growth of cells and accumulation of XMP leaving 5'-inosinic acid unaffected. The maximal accumulation of XMP reached to 60.5 mg/l after 4 days of fermentation which had been started with a medium containing 100 mg of adenine-guanine, 5 mg of $MnSO_4{\cdot}H_2O$ and $100{\mu}g$ of biotin per liter. The specific XMP synthesis(mg of XMP/mg of cells) was increased with the increase of the cell growth rate.

• Journal of Life Science
• /
• v.20 no.6
• /
• pp.853-860
• /
• 2010

The DevSR two-component system is a major regulatory system involved in redox sensing in Mycobacterium smegmatis. The DevSR system consists of the DevS histidine kinase and its cognate DevR response regulator. When exposed to hypoxic conditions, the DevS histidine kinase is activated to phosphorylate the DevR response regulator, leading to the transcriptional activation of the DevR regulation. The ligand-binding state of the heme embedded in the N-terminal GAF domain of DevS determines the kinase activity of DevS. In this study, we demonstrated that the redox-responsive cysteine (C547) in the C-terminal kinase domain is involved in the redox-dependent control of DevS kinase activity. The formation of an intersubunit disulfide bond between the C547 residues in the presence of $O_2$ led to inactivation of DevS kinase activity. The reduction of the oxidized DevS with reductants such as $\beta$-mercaptoethanol and dithiothreitol resulted in the restoration of DevS kinase activity. It was demonstrated in vivo by complementation test that the substitution of C547 to alanine partially impaired the sensory function of DevS in M. smegmatis.

• Korean Journal of Food Science and Technology
• /
• v.3 no.3
• /
• pp.163-167
• /
• 1971

Tasty constituents of the Chinese quince such as polyphenols, amino acids, sugars and organic acids were surveyed through the course of this study. The results are as follows: 1. The major moiety of the polyphenol constituents were catechin, leucoanthocyan, and associated tannins. 2. Amino acids were mostly composed of aspartic acid, glutamic acid, arginine and ${\beta}-alanine$. 3. Citric and malic acids were the main organic acids. 4. Sugars detected were glucose, fructose, sucrose and xylose. 5. When compared with apple and/or pear: the total amount of amino acids were quite similar, sugars decreased from half to one third, but the total amount of polyphenol constituents increased from 20 up to 50 times and 3 to 5 times in organic acids. These indicates unambiguously that the origin of rough and acidic taste is due to these high level of polyphenols and organic acids.

• Food Science and Preservation
• /
• v.19 no.5
• /
• pp.645-651
• /
• 2012

The food functional properties of Pleurotus eryngii cultivated with different wavelengths of light-emitting diode (LED) light were analyzed in this study. The levels of total soluble solids of Pleurotus eryngii increased with all the LED lights, except mixed LED light ($B^*R$, $B^*G$ and $R^*G$). Thirty one kinds of components were detected by analyzing the free amino acids. The total free amino acid contents had a slightly higher tendency in the control group, but the ratios of eight essential amino acids among the total amino acids of Pleurotus eryngii cultivated under all the LED lights, including the blue light (blue, $B^*R$, $B^*G$ and $B^*R^*G^*U$) and the green light, were higher than that in the control group. K was the highest-content of mineral, and Mn was the lowest-content. The Ca content increased through cultivation under all the LED lights, except the blue light, but the Fe content (under the green and $B^*R$ lights), K content (under the red and UV-A lights) and Mg content (under the $R^*G$, UV-A and red lights) increased under the exclusive LED light. The total phenolic compounds increased by cultivation under all the LED lights, except the UV-A and mixed lights ($R^*G$ and $B^*R^*G^*U$). The DPPH radical scavenging activity was also improved by all the LED lights, except the mixed light ($R^*G$).

• Food Science and Preservation
• /
• v.9 no.1
• /
• pp.28-35
• /
• 2002

This study was conducted to evaluate the quality characteristics of different soy sauces. The soybean sauces brewed tty the A. oryzae koji(SAO), M. pilosus-1 koji(SMP) and the mixture of 50% M. pilosus-1 koji(SAM) during 90 days fermentation. Total nitrogen contents of the SAM, SAP and SMP were 13.6%, 1.15% and 1.22%, respectively. Content of amino type nitrogen in SAM was 0.78%, and the content was higher than those of SAO and SMP. Total free amino acid contents of SAO, SMP and SAM were 533.8, 732.4 and 807.3 mg/100 mL. The highest contents of free, amino acids were glutamic acid(65.20 mg/100 mL) in SAG, alanine(101.42 mg/100mL) in SMP, glutamic acid(130.52 mg/100 mL) in SAM. The highest activities of pretense and ${\beta}$-amylase showed in SAM, and the lowest activities of ${\alpha}$-amylase and glucoamylase were in SAO and SMP respectively. Hue angle values showed 56.3 in SAO, 29.0 in SMP and 32.2 in SAM. Monacolin K contents, as inhibitor of cholesterol bio-synthesis were 6.21 $\mu\textrm{g}$/mL for SMP and 3.10 $\mu\textrm{g}$/mL for SAM, and the inhibitory activities of SMP ane SAM aginst HMG-CoA reductase were 21.5 md 10.2%, respectively. Sensory scores for color, flavor, savory taste and overall taste of SAM was higher than those of SAO and SMP.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.4
• /
• pp.579-588
• /
• 2001

In order to investigate the composition and monthly variation of extractive nitrogenous components in the laver Porphyra dentata cultured at the south coast of Korea, the fresh laver was analyzed separately for the amounts of free amino acids, combined amino acids, ATP and its related compounds, and quaternary ammonium basis in fresh laver were measured. The extractive nitrogen contents of fresh laver extracts were 760~870 mg/100g (dry basis). Twenty-seven to thirty-one kinds of free amino acids were detected in the laver extracts and their total amounts were 2,404~3,966 mg/100g (on dry basis). The laver extracts showed rich in free amino acids such as alanine, taurine, glutamic acid, glutamine and aspartic acid. Sixteen to twenty-three kinds of combined amino acids were detected in the extracts and their total amounts were 1,429~2,692 mg/100g (on dry basis). Proline, glutamic acid, glycine, phosphoserine, serine were the amin combined amino acids in the extracts. The amounts of ATP and related compounds were 73.3~94.4 mg/100 g (2.04~4.43 $\mu$mol/g, on dry basis). Homarine and trigonelline were detected in all specimens but $\beta$-alaninebetaine, ${\gamma}$-butyrobetaine were found in some. Small amounts of trimethylamine were detected in all samples. Free and combined amino acids were occupying almost 90% of extractive nitrogen. Most of free and combined amino acids showed a marked monthly variation with a maximum in January and March, and a minimum in February and April. The fresh laver P. dentata did not differ much from the fresh laver P. yezoensis in qualitative com-position of extractive components, but their contents were generally low level.

• Korean Journal of Food Science and Technology
• /
• v.31 no.6
• /
• pp.1458-1464
• /
• 1999

The whole body of three species of fishes, raw anchovy (Engraulis japonica), big eyed herring (Harengula zunasi), and northern sand lance (Ammodytes personatus) catched at the south adjacent coast of Korea, were analyzed for extractive nitrogen, free amino acids, combined amino acids, ATP and its related compounds quaternary ammonium bases, and guanidino compounds using specimens collected in May and July 1991, and the composition of these nitrogenous components were compared with each other. The contents of extractive nitrogen in anchovy, big eyed herring, and northern sand lance were 633 mg, 601 mg, and 455 mg/100 g, respectively. Thirty-one or thirty-two kinds of free amino acids were found in the extracts of the three species of fishes. Histidine, taurine, alanine, leucine, carnosine, glutamic acid, and lysine were the major free amino acids in every sample. The composition of the major extractive components such as free amino acids, combined amino acids, ATP and its related compounds, TMAO, and creatine in the extracts were similar to each other, but their contents were some different individually.

• Food Science and Preservation
• /
• v.19 no.4
• /
• pp.594-603
• /
• 2012

This study developed a high-utility type of vinegar from Rubus coreanus by optimizing its fermentation conditions. In the alcohol fermentation process, the optimal conditions for the maximization of the alcohol contents were an initial sugar concentration of 15 $^{\circ}Brix$, a temperature of $30^{\circ}C$ and 4 days. The optimal conditions for the acetic acid fermentation were 9 days of fermentation at $30^{\circ}C$ and 200 rpm, with 6% alcohol and 2% initial acidity. The sucrose, fructose, and glucose contents were 952.90, 491.01, and 386.62 mg%, respectively. The free organic acids were acetic, malic, succinic, malonic, oxalic, and lactic acids. The total free amino acid content was 104.33 ${\mu}g/mL$, with alanine, glutamic acid, ${\gamma}$-amino-N-butyric acid, and o-phospho-ethanolamine as the major amino acids. The K, Na, and Mg contents were 1,686.10, 172.50, and 69.33 ppm, respectively. The total phenolic and anthocyanin contents were 25.19 and 80.71 mg/100 mL, respectively. The DPPH- and $ABTS^{.+}$ radical scavenging activities were approximately 65 and 94%, respectively. Moreover, the vinegar's ${\beta}$-carotene bleaching activity and reducing power showed that it had strong anti-oxidant properties. These results show that Rubus coreanus vinegar has anti-oxidant properties and may be used as functional food.

• Food Science and Preservation
• /
• v.10 no.4
• /
• pp.534-539
• /
• 2003

This study was conducted to analyze components of the fruit of Etaeagnus multiflora to form a part of studies on the nutritional and functional materials of fruits and leaves of E. multiflora, and the development of a functional food. The moisture content of the fruit was 82.34%, and the content of carbohydrate, crude protein, lipid and ash was 15.4, 1.29, 0.79 and 0.54%, respectively. The pH of the fruit extract was 3.29, acidity 0.64%, and brix 14.0. Total sugar was contained 1.03/100g and reducing sugar was 3.27 g/100g. The content of soluble protein was 0.48 g/100g, and polyphenol was 0.28 g/100g. The glucose and fructose as a free sugar was 401.96 and 370.34 mg/100g, and account for a great portion of the components. Total content of free sugary was 0 mg/100g. The total amount of organic acid was 294.44 mg/100g, and the content of citric acid was 265.01 mg/100g, malic acid 18.16 mg/100g, and succinic acid 8.50 mg/100g. In the free amino acid, the concentration of serine was the highest (13.93mg/100g), and alanine, aspartic acid, cystine and methionine were high in the above order. The content of ascorbic acid was 131.35 mg/100g and that of dehydroascorbic acid was 431.37 mg/100g. Potassium, magnesium and sodium content were 627.44, 140.28, and 56.70 mg/100g, respectively.