• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.962-968
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• 2002

Effects of gamma-irradiation of 1 to 10 kGy on the microbial growth, contents of amino acids, fatty acids, and free sugars, and changes in acid values in soybean powder were studied. Irradiation doses at $3{\sim}5\;kGy$ inhibited the mold growth completely in two kinds of imported soybean powders. Contents of sulfur-containing amino acids, such as cysteine, in both soybean powders decreased with irradiation, whereas no significant changes in free amino acid and fatty acid contents of both soybean powders were observed. Free sugar contents of stachyose and sucrose in Chinese soybean powder decreased with increasing irradiation dose level, whereas, those of other sugars remained unchanged. Results of this study confirm that $3{\sim}5\;kGy$ irradiation can be safely applied to apply to soybean powder without causing significant quality deteriorations microbiologically and chemically.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.720-726
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• 1995

Chemical components relevant to the characteristic taste of the Korean native persimmon(Diospyros kaki, Thumb) leaf tea were analyzed. Samples were processed by using three different methods ; SHT(steamed and then hot-air dried), DHT(dried in the shade, steamed and then hot-air dried) and RHT(roasted and then hot-air dried). The components analyzed were general compositions of dried perisimmon leaves and extracted solution. The composition of moisture, ash, crude lipid and total nitrogen did not show significant variation among different processing methods of the persimmonleaf tea. The contents of caffeine, tannin and vitamin C in persimmon leaf tea were in the range of $178.4~209.8{\mu}mol/g$, 29.1~38.5mg% and 325.3~2084.7mg%, respectively. The vitamin C content was significantly higher in the RHT than other treatments. The contents of caffeine, tannin and vitamin C in the tea extracted solution were in the range of $101.5~130.1{\mu}mol/g$, 15.4~25.9mg% and 111.0~1274.3mg%, respectively. The vitamine C in the tea solution was the highest in the RHT treatment and 61.1% of vitamin C in the leaf tea was extracted out in these processing methods. The major amino acids contained in the leaf tea were in decreasing order glutamic acid, aspartic acid, leucine and phenylalanine, these four amino acids consisting 38.9~39.8% of the total amino acid contained in the persimmon leaf tea. The major amino acids contained in the tea solution were glutamic acid, proline, histidine and arginine. Six kinds of 5'-nucleotides, CMP, AMP, UMP, IMP, GMP and hypoxanthine were detected and CMP was the most abundant component in fresh leaf, leaf tea and tea solution. The second highest 5'-nucleotides in both leaf tea and tea solutions were GMP, AMP and UMP in all processing method. The highest free sugar contained in the fresh leaf tea and tea solution was sucrose.

• Culinary science and hospitality research
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• v.20 no.2
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• pp.65-78
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• 2014

This study was aimed to develop short necked clam stock, which is the base of sauce, soup, etc., using various nourishing elements in short necked clams. In short necked clam stock with different heating times, the moisture content was significantly different (p < 0.05). For the color value of short necked clam stock, L value was the highest in S1(31.15), while the highest a value was found in S5(-0.36) and the highest b value in S5(0.67). pH was the lowest as 7.35 in S5. When heating time increased, pH decreased significantly (p < 0.001). The sugar content was the highest as $3.30^{\circ}Brix$ in S5 and the lowest as $2.63^{\circ}Brix$ in S1. The salinity content was the lowest as 0.73% in S1, and it increased significantly(p < 0.001) with increased heating time. Na was the highest among the mineral contents and the highest K, Mg, Ca, Fe contents were found in S5 heated for 60 mins. Twenty one kinds of free amino acid were detected in short necked clams. The highest essential amino acid content was arginine, the highest flavor enhancing free amino acid was glycine, and the highest derivative amino acid was taurine. The test for characteristic differences of short necked clam stock showed that savory taste and savory flavor of S4 heated for 50 mins were the highest. According to the results of acceptance test, S3 showed the best results. In conclusion, short necked clam stock showed great preference with increased heating time, and the preference has increased when it was simmered for 35~40 mins.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.132-137
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• 2010

This study was performed to investigate the effect of apple and maltitol as ingredients on the quality of Jochung, a grain syrup. Four kinds of Jochung products were prepared from steamed-rice, apple juice, heated-apple sarcocarp (at $70^{\circ}C$, 60 min), and a mixture (sarcocarp : maltitol＝5:1, w/w) by saccharifying (at $55^{\circ}C$, 8 hrs) with a malt (100 g/500 g rice), mixing the ingredients (steamed-rice : ingredient＝5:5, w/w), filtering, and heating the filtrate (at $95^{\circ}C$, 2 hrs): product (A) with apple juice added before saccharified, product (B) with apple juice added after saccharified, product (C) with heated-apple sarcocarp added after saccharified, and product (D) with the mixture added after saccharified. The product (D) had the lowest pH value ($4.60\pm0.01$) of any other products. The contents of reducing sugar and total phenolic compound were the highest in the product (A) among all the products, which comprised $68.10\pm6.71$% and $7.36\pm0.85$ mg/g, respectively, resulting in good quality. The solidity and the dextrose equivalence had the highest value in the product (B) and the product (C), respectively. The malic acid content ($4.10\pm0.02$%) of the product (D) was the highest of any other organic acids identified by HPLC. Hunter L, a, and b values of the product (D) were the highest compared to other products. In sensory evaluation, the product (A) had generally higher score in all sensory attributes. It was concluded from the chemical and sensory evaluation that adding the apple juice before saccharified might be an effective method for manufacturing good quality rice-Jochung.

• Food Science and Preservation
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• v.24 no.6
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• pp.849-856
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• 2017

In this study, we investigated the variation in free sugars, organic acids, amino acids, antioxidant activity and anti-inflammatory effect of Solanum nigrum Linne fruits according to harvest time. Four kinds of free sugars (fructose, glucose, sucrose, maltose) were detected in S. nigrum fruit, and the free sugar contents varied significantly with harvest time. Organic acid content of S. nigrum fruit showed the highest in malic acid and acetic acid, and the highest content of total organic acids was found in S. nigrum fruit harvested on October $18^{th}$ and October $25^{th}$. For the total polyphenol content, S. nigrum fruit harvested on October $18^{th}$ was the highest. The strongest DPPH and ABTS radical scavenging activity was showed in S. nigrum fruit harvested on October $11^{th}$ and October $18^{th}$. The anti-inflammatory activity and antioxidant effects were the highest in the ethanol extract from S. nigrum fruit collected on October $18^{th}$ and October $11^{th}$. Thus, it seems the best to harvest of S. nigrum fruit harvested on October $11^{th}$ and October $18^{th}$.

• Korean Journal of Food Science and Technology
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• v.42 no.6
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• pp.739-742
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• 2010

In order to select a superior yeast, 8 kinds of commercial active dry yeasts (Lalvin 1116, Lalvin 1118, Lalvin D-47, Lalvin Bourgovin, Parisienne, Fermivin, Red Star Monrachet, and Red Star Premier Cuvee) were utilized for omija wine fermentation. During fermentation, the physicochemical characteristics and sensory properties of the various omija wines were evaluated. According to the results, pH and titratable acidity were in ranges of 3.0-3.3% and 1.8-2.4%, respectively. Sugar content was $24^{\circ}Bx$ at early fermentation and changed to $8.4-10.2^{\circ}Bx$ at 24 days of fermentation. While the omija wines fermented by Lalvin D-47 and Red Star Premier Cuvee showed the highest alcohol contents (13.0%), the omija wine fermented by Parisienne showed the lowest alcohol content (10.8%). The omija wine fermented by Lalvin 1118 had an alcohol content of 12.0% and showed the lowest yeast count of 5.8 log CFU/mL. Hunter's values (L, a, and b) were all different among the 8 omija wines. Moreover, the omija wine fermented by Lalvin 1118 showed the highest scores for taste ($6.75{\pm}1.68$), swallowing ($6.65{\pm}1.50$), and overall acceptability ($6.70{\pm}1.34$). It is concluded that Lalvin 1118 was the best yeast among 8 tested commercial active dry yeasts, having a high potential for omija wine fermentation.

• Food Science and Preservation
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• v.20 no.3
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• pp.404-418
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• 2013

This study was conducted to investigate changes in the physicochemical properties (proximate compounds, reducing sugar, organic acid, ATP and related compounds, and free amino acid) of beachu kimchi (BK) with octopus, abalone, squid and webfoot octopus added during its storage at $4^{\circ}C$ for 35 days. The crude protein content of the seafood Kimchi, 1.98~3.41%, was higher than that of the BK. The organic acid level did not significantly differ in the four kinds of seafood during their fermentation, and their malate and succinate contents decreased while their lactate content increased. The levels of the ATP and related compound substances of the hypoxanthine contents were high but decreased during their fermentation. However, $3.40{\mu}mol/g$ of IMP was detected in the Kimchi with octopus added; $0.67{\mu}mol/g$ in the Kimchi with abalone added; and $1.80{\mu}mol/g$ in the Kimchi with squid added after they were fermented for 21 days, but the same were not detected in the BK. The taurine and ${\gamma}$-amino-n-butyric acid contents of the free amino acids in the seafood Kimchi were approximately two to 10 times and 1.5 to three times higher than in the BK, respectively.

• Applied Biological Chemistry
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• v.9
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• pp.9-27
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• 1968

Studies were carried out in order to elucidate chemical components and microflora in three types of soy-sauce, 12-year aged soy-sauce prepared by improved method. 7-year aged and 20-year aged soy-sauce prepared by ordinary method. They results are summarized as follows: 1. The followings are found to be the important factors affecting the quality of soy sauce. a. Organic acids, reducing sugars and free amino acids were increased in the course of storage. b. In the aged soy-sauces under study non-volatile organic acid increased while volatile organic acid decreased and the total acidity was dependent only upon tie latter. c. It was found that suit concentration decreased during the storage. 2. The results of investigation of microflora in the stored soy-sauce are shown as follows. Soy-sauce Improved Ordinary Microbe 12-Y. 20-Y. 7-Y. Aerobic bacteria colony/1ml. 6 123 2 Halophilic lactic acid bacteria colony/1ml. 4 6 10 Osmophilic yeast colony/1ml. $828{\times}10^4$ 248 - b. In the stored soy-sauces, aerobic bacteria are incapable of growing due to drop in pH value and the influence of salt concentration. c. Halophilic lactic acid bacteria are incapable of growing due to drop in pH value, even the salt concentrations decreased during the storage. d. Osmophilic yeast are still growing in low pH value and in the decreasing salt concentration during the strage. 3. The results of amino acid analysis by paper partition chromatographic and calorimetric methods are shown as follows. a. Fourteen kinds of amino acid and thirteen amino acids were detected in the soy-sauce of 12-year aged improved soy-sauce and 7-year aged and 20-year aged ordinary one, respectively. b. The contents of aspartic acid, glutamic acid, serine, valine, leucine, lysine, histidine and methionine increased in the 20-year aged ordinary soy-sauce compared to the 7-year aged one. On the other hand those of alanine, tyrosine, phenylalanine and cystine decreased. 4. The results of sugar analysis by paper chromatography are as follows. a. In the 12-year aged improved soy-sauce, galactose, glucose, arabinose, xylose, rhamnose, maltose and an unknown were detected, and their amounts were in the above order except maltose and an unknown. b. Both in the 7 and 12-year aged ordinary soy-sauces, galactose, arabinose, xylose, glucose and rhamnose were detected and the amounts of the sugars were in the above order. c. In the non-aged ordinary soy-sauce, glucose was not detected but detected from 7-year and 20-year aged ordinary soy-sauce. 5. The results of organic acid analysis by paper chromatography were as follows. a. As volatile acids, acetic, propionic and butyric acids were detected in the 7-year aged ordinary soy-sauce. On the other hand in both the 20-year aged ordinary soy-sauce and the 12-year aged improved ones, only acetic acid was abundant while propionic and butyric acids were round in trace. It was found that propionic and butyric acids, as the unpleasant flavor components, decreased during the storage. b. In the ordinary soy-sauce, citric acid were produced during the storage and lack, malic and tartaric acids increased in the course of aging while succinic, glycolic, fumaric and malonic acids were shown to decrease. Glutaric and oxalic acids disappeared. Citric acid was produced also in the improved soy-sauce, but lactic, tartaric, succinic, malic, and glycolic acids decreased, while both malonic and glutaric acids disappeared. From the above results the citric acid production was considered to be a favorable factor for the taste. c. In the aged soy-sauces, pyruvic, α-ketoglutaric and probably acetoacetic and oxaloacetic acids (both in trace) were present and their amounts were in the above order. All of the α-keto acid abruptly decreased during the storage.