• 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.

• Journal of the Korean Society of Food Culture
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• v.31 no.4
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• pp.348-356
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• 2016

The purpose of this study was to investigate the chemical contents (sugar, nitrogen, and amino acids) and sensory characteristics of traditional soy sauce according to three different methods. The samples were taken from four different periods (0, 20, 40, and 60 days after fermentation). Total sugar contents increased in all groups according to ripening period, and Gyupjang (G) showed the highest sugar content among the groups. Total nitrogen and amino acid contents of all groups increased after 60 days of ripening, and Gyupjang (G) and Gyupjang mixed with salt water (SG) had higher total nitrogen content compared to Chungjang (S) at the same period. The results from the sensory evaluation show that preferable sensory characteristics, such as color preferences, sweetness, umami taste, and overall preference, were significantly higher in Gyupjang (G) and Gyupjang mixed with salt water (SG) than in Chungjang (S). Preferable sensory characteristics had significantly high positive correlation with most amino acids, total nitrogen, and sugar contents, except for glutamine. Based on the significant difference in preferable sensory characteristics between Gyupjang mixed with salt water (SG) and Chungjang (S), Gyupjang mixed with salt water (SG) can be used to improve sensory characteristics. This research implies that adding salt water during the manufacturing Gyupjang process is advisable to yield high quality soy sauce.

• Korean journal of food and cookery science
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• v.16 no.2
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• pp.99-111
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• 2000

The purpose of this study was to assess the qualities of cook/chilled soy sauce-glazed soybean curd with various packaging conditions as a trial to develop health-oriented convenience foods. The effects of three packaging methods, linear low density-polyethylene (LLD-PE), top sealing, and modified atmosphere packaging(MAP) on the shelf-life of HACCP-based cook/chilled soy sauce-glazed soybean curd were evaluated during 20 days of chilled storage in terms of time-temperature, microbiological (total aerobic plate count, psychrotrophic plate count, coliform, and fecal coliform count), chemical(pH and peroxide value(POV)), and sensory evaluation. The results of microbiological and chemical analyses were within the limits of the microbial and chemical standards for all phases after cooking. No significant differences were detected in microbial counts of the samples for all three packaging methods. However, sensory evaluation indicated that the top sealing and MAP methods showed a longer shelf-life than LLD-PE packaging. Recommended shelf-life of the product was 12 days for LLD-PE packaging, and 16 days for both top sealing and MAP. In conclusion, MAP was considered as the most effective packaging method for assuring microbial and sensory quality of this cook/chilled product.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1447-1458
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• 2009

Volatile extracts obtained from traditional Chinese-type soy sauces prepared with soybean (SSSB) and defatted soy meal (SSDSM) by solid phase microextraction (SPME) and direct solvent extraction (DSE) were analyzed by gas chromatography-mass spectrometry (GC-MS). The volatile flavor compounds and relative contents of different chemical classes detected in SSSB and SSDSM were compared for their differences. Results showed that significant differences in both constituents of volatile flavor compounds and relative contents of different chemical classes were observed for both kinds of soy sauces. A total of 152 and 131 compounds were identified in SSSB and SSDSM, respectively, and 102 volatile flavor compounds were common in both kinds of soy sauces. Moreover, relative contents of acids, aldehydes, esters, furan(one)s, miscellaneous compounds, phenols, pyrazines, pyrrol(idinon)es, and sulfur-containing compounds in both kinds of soy sauces were all significantly different.

• Korean Journal of Food Science and Technology
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• v.4 no.3
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• pp.182-186
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• 1972

The possibility of substituting corn or barley for the wheat, one of the raw materials for soy sauce, was studied by measuring the amylase and proteolytic activities of koji. Also optimum conditions of koji making were determined. It was found that substitution of up to 60% of wheat content (of the total bean and wheat content) with corn, yielded good quality of soy sauce. It is also found that barley can substitute 70% of wheat content (35% of the total content).

• Korean Journal of Food Science and Technology
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• v.7 no.4
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• pp.200-207
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• 1975

This experiment was carried out to investigate the chemical composition and microflora of soy sauce during storage under the different temperature. The results obtained are as follows. (1) Total nitrogen, color density, specific gravity and sodium chloride concentration of soy sauce showed a increasing tendency in the progress of storage period. Open-storage state at $30^{\circ}C\;and\;15^{\circ}C$ were responsible to the increase of components as compare with close-storage state at $5^{\circ}C$. (2) pH and buffer action were not almost changed during the storage. (3) Alcohol and sugar contents of soy sauce showed a decreasing tendency in the process of storage period, especially in the case of open state alcohol being almost disappeared within 11 months in all groups. (4) The number of common bacteria in one ml of soy sauce were counted as $96{\times}10^4$ before pasteurization and $10^3$ after pasteurization. The osmophilic bacteria was counted as $38{\times}10^4$, $10^2$ after pasteurization. (5) The spore number of mold in one ml of soy sauce were counted $32{\times}10^7$ before pasteurization, 58 after pasteurization and 10 to $10^2$ in the progress of storage period. (6) The bacteria number of soy sauce were somewhat decreased with the passing, of the time. The group of high temperature and open state were more notable than low temperature and close state.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.714-719
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• 2001

An interest in traditional foods is growing in an effort to preserve dietary culture in Korea. Blue crab preserved in soy sauce, one of the Korean traditional foods is especially popular in summer and is produced in the Jeollanam-do province, Korea. However, there has been no report on processing of the blue crab. The objective of this research is to investigate changes of nutritional composition in blue crab preserved in soy sauce. Moisture content was a little higher in FBC (Fresh Blue Crab) than in PBC (Preserved Blue Crab) and ash content was greatly higher in PBC than in FBC. Salt content was 1.50% in FBC and 7.89% in PBC. The amount of free sugars in FBC was very low but was increased after preserved using soy sauce, especially of fructose significantly. After preserved, the pH of blue crab was also increased. The contents of most total amino acids in blue crab were decreased after preserved, but free amino acids were increased. Major total amino acids were glutamic acid, arginine and aspartic acid in two samples and major free amino acids were arginine, proline and alanine. Fatty acid content was decreased after preserved and major fatty acids were palmitic acid (16 : 0), oleic acid (18 : l), eicosapentaenoic acid (20 : 5) and docosahexaenoic acid (22 : 6).

• Applied Biological Chemistry
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• v.44 no.2
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• pp.81-87
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• 2001

Oyster jeot-gal were prepared in the form of salt-fermented oyster and oyster in soy sauce tentatively and used for investigation the retarding effect of its fermentation in a vacuum from the physicochemical and microbiological points of view. $_PH$ value decreased slightly but amino-N (AN) and volatile basic nitrogen (VBN) increased inversely during the fermentation periods. AN contents were greater in vacuum fermentation than in non-vacuum, whereas VBN were greater in non-vacuum. Total viable cell counts were similar to trend of gentle decrement after increment to some degree but showed higher in non vacuum than in vacuum. In vacuum product, total amino acid contents increased with the elapse of fermentation days or in time of reduction those were higher than in non-vacuum. On the results of chemical analysis, it showed that fermentation was delayed in vacuum and that vacuum fermentation was effective for the shelf-life extension of jeot-gal.

• Applied Biological Chemistry
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• v.4
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• pp.17-22
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• 1963

Changes of Enzymatic activities and chemical components during Koji preparation of soy sauce with various ratio of soy bean and wheat were studied as first step for checking the current ratio of raw materials for improved soy sauce and determination of proper ratio of them in the respect to its quality and taste, and following results could be obtained. 1. The Protease in the dryed Koji were mainly conmposed of a part which active at the neutral (about pH 6.0) range, while parts which active at acid and alkaline side were inferior. The more amount of wheat increases as raw materials of Koji, the stronger Protease activities of acid and neural side were, while the weaker alkaline side were. 2. Activity of Enzymes were increased rapidly in earlier stage then gradually in later stage or Protease and ${\beta}-Amylase$ rapidly throughout except drying of ${\beta}-Amylase$ during the course of Koji preparation. The more amount of wheat as raw material increases, the stronger Protease and ${\beta}-Amylase$ activity except. ${\beta}-Amylase$ were. 3. Reducing sugar, amino nitrogen, total nitrogen were increased, while total sugar were decreased during the course of Koji preparation. 4. The more amount of wheat increases as raw materials, the more increase reducing sugar, total sugar were, while the total nitrogen were decreased, no noticeable differences were observed in the amino nitrogen among the dryed Kojies.

• Korean Journal of Microbiology
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• v.7 no.2
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• pp.63-85
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• 1969

This study was carried out in order to obtain clear knowledge about the effects of Aspsulphueus which is parasitic on the bean paste ball, meju, made to brew soy sauce and bean paste for domestic uses in the general silkworm rearing farmhouseholds in Korea. The major research carried by the author during the past five years (1965-58) includes, 1) the cause of disease, 2) symptoms, 3) morphological and chemical changes of the larval body tissues and 4) methods to prevent the contagion of the disease.