• Journal of the Korean Society of Food Science and Nutrition
• /
• v.18 no.1
• /
• pp.115-122
• /
• 1989

The mechanisms of aflatoxin $B_1(AFB_1)$ degradation by ammonia and alkaline pH during the storage of Korean soy sauces were studied. In the 0.05%, 0.1% and 0.5% of ammonia solutions, almost all of $AFB_1$(96-100%) was degraded after 2 to 24 hrs of incubation at $30^{\circ}C$. Increased levels of ammonia in both home made soy sauce(HMSS) and commercial soy sauce(CSS) caused slow increases in pH. The pH change was higher in CSS than in HMSS. The degradations of $AFB_1$ were not observed in the samples of HMSS, CSS, distilled water and 20 % of NaCl solution during the storage, however, when the pHs of the samples were adjusted to 10, the toxin was completely removed in all samples. $AFB_1$ was stable at pH 5 and 7 in bath buffer solutions and buffer solutions+0.2% ammonia, however, $AFB_1$ was degraded completely at pHs more than 9. $AFB_1$ was not degraded even at high concentrations of ammonia(0.2-1.0%) when the pH was maintained at 7 in the buffer solution. It indicated that ammonia content in the system was not important but the higher pH was the reason to degrade $AFB_1$. When the pHs of HMSS, CSS, buffersolution and buffer solution + 0.2% ammonia were adjusted to 5 and then reacted with $AFB_1$ for 5 days, the toxin was stable in all samples. However, when the pHs of the samples were adjusted to 7, about 60-70 % of $AFB_1$ was degraded in HMSS and CSS after 5 days of incubation during which the pH was not changed, but $AFB_1$ in the buffer solution and buffer solution + 0.2% ammonia was not degraded at all in the same conditions.

• Applied Biological Chemistry
• /
• v.22 no.2
• /
• pp.91-96
• /
• 1979

Several herbs were tested for their antimicrobial activities during preservation of soy sauces. The herbs which resulted in retarded growth of film yeasts were extracted and added to various media such as koji-extract agar, buion-peptone agar to elucidate effects on the growth of film yeasts, Aspergillus oryzae and Bacillus subtilis. The results obtained were as follows: 1) Addition of phellodendron powder resulted in retarded formation of film in fermented soy sauces. Film was produced after 2 days without addition of the phellodendron powder. However, formation of film was observed after 8 days when 0.5 per cent of the phellodendron powder was added, and after 12 days when 1.0 per cent of the powder was added to fermented soy sauce. 2) For the amino acid soy sauce, formation of film was retarded for 6 days by 0.5 per cent of the pow der and for 8 days by 1.0 per cent of the powder. 3) Repression of film yeasts by addition of helenii and camphora powder was recognized respectively, but other herbs were appeared to have no detectable effects. 4) Growth of film yeast and Asp. oryzae way, retarded for 5 days on koji-extract agar plates which contain 0.5 per cent of phellodendron extract. Bac. subtilis also showed retarded growth for 5 days on buion-peptone agar plates containing the same amount of the extract. 5) Retarded growth of film yeast for 5 days was obtained when grown on koji-extract agar plates containing 15 per cent of sodium chloride and 0.3 per cent of phellodendron powder, however, no growth of Asp. oryzae was obtained on this concentration of sodium chloride. Growth of Bac. subtilis was repressed for 5 days on buion-peptone agar plates which contain 15 per cent of sodium chloride and 0.1 per cent of phellodendron powder.

• Microbiology and Biotechnology Letters
• /
• v.26 no.5
• /
• pp.450-455
• /
• 1998

Aspergillus oryzae M-2-3 strain (argB$\^$-/) was transformed with pTAalp plasmid which was constructed for expression of the alkaline pretense gene, alpA, and 16 transformants were selected on arginine minus medium. When these transformants were tested for productivity of alkaline proteases using agar plate containing skim milk, the halo was observed around each colony of transformants, but not observed around the host strain in this condition. Southern analysis showed that the pTAalp plasmid having alpA gene was integrated into the chromosome of the host strain. The highest level of alkaline protease production was obtained in the culture filtrate of the transformant No. 14, which was estimated to 80-90% of total secreted proteins, and the enzyme activity was 64-450 times higher than those of host strain and industrial strain. Total nitrogen content and the digestion rate in soybean Koji extracts were also increased to 1.5 times in Aspergillus oryzae transformant No. 14.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.8
• /
• pp.1177-1185
• /
• 2003

The contents of organic acids in traditional and modified fermented foods were compared, and propionic acid produced during fermentation was investigated. Organic acids in traditional and modified soy sauces were lactic acid, acetic acid, citric acid, formic acid, succinic acid and oxalic acid while propionic acid was found in traditional soy sauces only. Similarly, lactic acid, acetic acid, citric acid, oxalic acid, formic acid, succinic acid and propionic acid were found in traditional and modified soy paste. The organic acids in traditional and modified kochujang were citric acid, acetic acid, formic acid, lactic acid, malic acid, oxalic acid and succinic acid while propionic acid was not found in modified kochujang. The major organic acid in persimmon and commercial (fermented) vinegars was acetic acid. Propionic acid was uniquely found in persimmon vinegars. Also, content of tannic acid in persimmon vinegars was 366.9 ∼ 909.8 mg%.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.4
• /
• pp.550-556
• /
• 2014

Rice bran contains both excellent nutritional value and functional advantages. Its utilization is limited due to reducing texture and low storage. To satisfy various tastes, Bacillus spp. having high amylase and protease activities were selected. Using the strains, we made whole grain soybean Meju with a reduced manufacturing period by increasing the concentration of total nitrogen. We made soy sauces with mashing ratios of soy bean and rice bran at 10:0, 9:1, 7:3, and 5:5, and then compared their physiochemical properties. After 2 weeks of fermentation, the sugar content increased from 21~22% to 30~32%. However, pH and salinity showed no differences. At a ratio of 9:1, total nitrogen, amino nitrogen content, and total free amino acid contents were the highest at 1.62%, 652.52 mg%, and 8,804.03 mg/kg, respectively, compared to other mashing ratios of soy bean and rice bran. Especially, the contents of aspartic and glutamic acid, which increase delicate flavoring, were higher in our soy sauce compared to those of general traditional soy sauce and brewed soy sauce, which were 504.25 and 1,262.25 mg/kg, respectively. Serine and alanine, which are related to sweet taste, were present at 49.50 and 518.75 mg/kg, respectively, which were the highest among all mixing ratios, at a ratio of 9:1. Compared to general traditional soy sauce and brewed soy sauce, the contents of histamine and tyramine among biogenic amines decreased to 35.85 and 41.04 mg/kg, respectively. Finally, a soy bean and rice bran mixing ratio of 9:1 was determined to be the optimal mixing ratio in the sensory evaluation.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.24 no.4
• /
• pp.19-25
• /
• 1979

Lowland and upland rice were grown under the both of lowland and upland conditions. Ecological variations in plant characteristics such as plant height, leaf emergence, length of leaf blade, leaf angle, leaf width, heading date, culm length, panicle length and straw weight were observed. Plant height, leaf emergence and heading were accelerated under the lowland condition for both lowland and upland varieties, while leaf length, leaf angle, leaf breadth, number of leaves were increased in upland condition for both lowland and upland varieties.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.2
• /
• pp.333-339
• /
• 1994

The metabolic transit of three samples( 14C glycine-glyucose melanoidin, glycine-glucose melanoidin and soybean sauce ) were studied on rats. The radioactivity of various organs and excreta intubated 14C glycine-glucose melanoidin on rats at various intervals(1, 3, 8, 12, 24, 48, 72 and 96 hrs were detected . And the brown pigment contents and hydrogen donating activities in the excreta which is obtained from three samples were detected during the 7 days after intubated. The total amount of 14C excreted in the fecese were 53% meaning that the rest of 47% melanoidin seemed to be retained in the body or metabolized . The radioactive compound showed a small retention in the liver and kidney. The brown pigment contents and hydrogen donating activities in the urine and feces increased proportionally to the activity of 14C. When the soybean sauce and glycine glucose melanoidin were intubated, the brown pigment contents excreted in the feces were found to be the highest after 1 st day of intubation. In the urine, the model melanoidin was excreted mostly after 3 days of intubation. The brown pigment contents and hydrogen donating activities of three samples of excreta agreed with each other. The soybean sauce retained longer than model melanoidin in the body is telling that it might have antioxidative activity in vivo.

• Journal of the Korean Society of Food Culture
• /
• v.28 no.6
• /
• pp.640-650
• /
• 2013

Soy sauce, a basic ingredient in Asian cuisine, is made of fermented soybeans, salt, water, and barley or wheat flour. The sensory characteristics of soy sauce are not only determined through its main ingredients but also by various flavor compounds produced during the fermentation process. This study was conducted to identify the sensory attributes of five different commercial soy sauce samples that differ in Meju types (traditional Meju or modified Meju) and usage types. Thirty three sensory attributes, including appearance (1), odor (16), flavor (14), and mouthfeel (2) attributes, were generated and evaluated by eight trained panelists. The collected data were analyzed by analysis of variance and principal component analysis. There were significant differences in the intensities of all sensory attributes among the soy sauce samples. Soy sauce made with traditional Meju had high intensity of fermented fish, beany, musty odors and salt, Cheonggukjang, fermented fish flavors. Whereas two soy sauces made with modified Meju were strong in alcohol, sweet, Doenjang, roasted soybean flavors. Two soy sauces for soup made with modified Meju had medium levels of briny, sulfury, fermented odors and bitter, chemical flavors and biting mouthfeel characteristic.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.5
• /
• pp.888-893
• /
• 2001

Soy sauce has a long history used as a food ingredient. However, hydrolyzed vegetable protein, mono-sodium glutamate, starch syrup, and fructose are added to soy sauce during fermentation for the taste and flavor of product. But consumers have been reluctant to the taste of these artificial additives. In this experiment, anchovy sauce was used to prepare soy sauce to enhance the quality and brine was used as a control. To evaluate the quality of soy sauce added with anchovy, total nitrogen (TN) and soluble nitrogen contents, total soild contents, total sugar reducing sugar. lactic acid content and protease activity were monitored during fer-mentation. Total microbial numbers and lactic acid bacteria were not significantly changed among the cases. Aerobic and anaerobic microorganisms. and lactic acid bacteria were not significantly changed among the cases we studied, For the total sensory test, it was also estimated that the cases using anchovy sauce were superior to the control. From the results mentioned above, we could obtain shorter fermenation period as well as the quality improvement in the case of using anchovy sauce instead of salty water in the fermented soy sauce production.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.6
• /
• pp.1152-1158
• /
• 1997

In order to develop new soysauce using mountain edible herbs, cirsium setidens Nakai and comfrey were added to the raw material of soysauce as a partially substituting ingredient to wheat composing the total nitrogen. The changes of chemical composition of soysauce by the substitution of 1~5% cirsium setidens after four months of aging were similar to those of the control soysauce. On the other hand, total solid content was decreased, while the pH was increased by more than 7%. The total nitrogen and solid contents in the confrey substituted soysauce were increased with the increment of the amount of comfrey, but showed little changes of the pH. The mineral contents of calcium and potassium in the soysauce after four months of aging at 10% substitution of cirsium setidens were increased by 1.7 and 1.4 times, respectively. A significant increase in calcium(2.3 times as compared to the control) was also observed in 7% substitution of comfrey. The amino acid contents such as methionine, tyrosine and histidine were markedly increased at 3% substitution of cirsium setidens. With 5% substitution of comfrey, the contents of tyrosine, glutamic acid methionine were increased by 4.4, 1.8 and 1.7 times, respectively as compared to the control. The results of sensory evaluation revealed that overall acceptability of soysauce with 1~5% substitution of cirsium setidens and 5% of comfrey exceeded other samples composing different ratios of substituting ingredients.