• Korean journal of food and cookery science
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• v.22 no.3 s.93
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• pp.291-298
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• 2006

This study, investigated the effect of changes in inoculum levels and fermentation temperature of chunggugjang prepared with Bacillus subtilis(B. subtilis) NRLSI IV on the quality characteristics. In chunggugjang prepared at different inoculum levels, viable cell count, reducing sugar and amino type nitrogen were maximized at $10^6\;CFU/mL$, whereas relative viscosity of viscous substance and hardness peaked at $10^2\;CFU/mL$. In sensory evaluation, chunggugjang made with $10^2\;CFU/mL$ showed higher values of appearance, color, taste and viscosity and a lower value of off-flavor than that made at other inoculum levels. Based on the results of ammonia type nitrogen, relative viscosity and sensory evaluation, the optimum inoculum level for chunggugjang prepared by B. subtilis NRLSI IV was $10^2\;CFU/mL$. In the second step, the effect of different fermentation temperatures on the quality changes of chunggugjang incubated with $10^2\;CFU/mL$ of B. subtilis NRLSI IV were investigated. The viable cell count was maximized at $40^{\circ}C$, but minimized at $45^{\circ}C$. Reducing sugar was not significantly different from $30^{\circ}C$ to $40^{\circ}C$ but was increased at $45^{\circ}C$. Increasing fermentation temperature decreased the content of amino type and ammonia type nitrogen. Chunggugjang prepared at $40^{\circ}C$ showed high sensory evaluation result in microorganism growth, appearance, taste and viscosity and particularly had low off-favor.

• Food Science and Preservation
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• v.18 no.5
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• pp.706-713
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• 2011

This study was conducted to investigate the chemical characteristics of Gochujang with different amounts of sweet persimmon powder added during fermentation at $20^{\circ}C$ for 90 days, in an effort to improve its taste and organoleptic quality. The moisture content was shown to be inclined to increase in all the treatments throughout the fermentation. There was no significant difference between the paste with sweet persimmon powder and the control. The pH showed a tendency to decrease with increased fermentation time in all the samples during fermentation, keeping a pH range of 4.64-4.67 after 60 days of fermentation. On the contrary, the titratable acidity increased during fermentation, showing a level of 0.147-0.156 mg% in the paste with sweet persimmon powder on the 90th day of fermentation. The sugar content was shown to be $33.67-39.67^{\circ}Brix$ in the early stage of fermentation, revealing a tendency to in crease with an increase in the amount of sweet persimmon powder added. The amino-type nitrogen content was at the 241.27-245.47 mg% level in the early stage of fermentation, and appeared to be significantly high (p<0.05) in the treatments with 3 and 4% sweet persimmon powder added, respectively, after 60 days of fermentation. The content was within the range of 357.47-371.53 mg% on the 90 th day of fermentation in the final stage, showing an increase trend throughout the fermentation. The alcohol content gradually increased with an increase in fermentation time, showing a range of 0.94-0.10% on the 90th day of the final stage of fermentation. Moreover, the content was highest (0.96-0.108%) on the 70th day of fermentation, demonstrating a trend to slightly decline in all the treatments thereafter.

• Korean journal of food and cookery science
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• v.29 no.6
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• pp.661-669
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• 2013

This study was performed to determine the optimal composition of Cheonggukjang added with garlic. The experiment utilized a central composite design (CCD). The evaluation was carried out by means of response surface methodology (RSM), which included 18 experimental points with three independent variables : the content of the garlic (1.3~9.7%, $X_1$), the steaming time of garlic (0~15.1 min, $X_2$), and the fermentation time of Cheonggukjang (48.2~71.8 h, $X_3$). The viscous substance ($Y_1$), acidity ($Y_2$), amino-type nitrogen ($Y_3$), ${\gamma}$-GTP activity ($Y_4$) and ABTS radical scavenging activity ($Y_5$). were assessed in four replicates with five dependent variables. The maximum content of the viscous substance was 13.02% at 6.53% ($X_1$), 6.81 min ($X_2$) and 55.18 h ($X_3$). The acidity was increased when the fermentation time was longer, and the minimum acidity point was 0.50% at 7.75% ($X_1$), 3.42 min ($X_2$) and 58.60 h ($X_3$), respectively. The content of the amino-type nitrogen at the experimental range studied was was 80.58~158.82 mg%, and the stationary point was at saddle point. Using ridge analysis, the maximum point was 156.97 mg% at 6.21% ($X_1$), 14.85 min ($X_2$) and 58.04 h($X_3$). The optimum conditions of ${\gamma}$-GTP activity was 5.73% ($X_1$), 6.99 min ($X_2$) and 57.96 h($X_3$), respectively, at the maximum point was 353.66 mU/mL. The maximum point of ABTS radical scavenging activity was 76.43% at 3.78% ($X_1$), 14.28 min ($X_2$) and 57.99 h($X_3$) at the saddle point, when the garlic steaming time was longer.

• Food Science and Preservation
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• v.22 no.3
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• pp.458-463
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• 2015

Many Koreans, who are resident in Uzbekistan and Central Asia, are still avid fans of the Korean traditional soybean paste. No research study has been conducted on the Korean-Uzbekistanis soybean paste. The purpose of this study was to investigate the quality characteristics of the Korean-Uzbekistanis fermented soybean paste. Nine kinds of soybean pastes prepared by Korean-Uzbekistanis were collected, and their physiochemical properties (protease activity, amylase activity, amino type nitrogen content, reducing-sugar contents, and aerobic bacterial count) have been analyzed. The Korean-Uzbekistanis' fermented soybean paste (KU-SP) showed higher protease activity than the Korean fermented soybean paste (K-SP). The protease activities of KU-SP B, D, and H were 832, 807 and 630 unit/g, respectively, which were significantly different from others. In addition, the content of amino-type nitrogen in KU-SP B, D, and H were 777 mg%, 686 mg%, and 705 mg%, respectively. In the meanwhile, ${\alpha}$-amylase activities showed wide ranges starting from 10.82 to 47.98 unit/g. The KU-SP values, except for the KU-SP C, have shown higher activities than the K-SP. The reduced sugar content and totoal aerobic bacteria number were within the range of 0.55~3.43%/g and 7.24~8.79 log CFU/g, respectively. Finally, this research provided the basic data and information for the quality characteristics of commercial soybean paste prepared by the Korean-Uzbekistanis. These basic data can be useful for understanding the Korean food culture in Central Asia.

• Food Science and Preservation
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• v.14 no.3
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• pp.294-300
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• 2007

Three varieties of soy sauce were prepared using saps of bamboo, xylem and gorosoe, with sea salt and bamboo salt, in May. Soy sauce was fermented in the traditional manner. Homemade soy sauce was analyzed after 3 months of aging. The pH and amino-type nitrogen content of soy sauce fermented with xylem sap and sea salt were very high, and malic acid was dominant among four types of organic acid. The content of calcium in soy sauce fermented with bamboo sap and sea salt was fourfold greater than that of the control. The contents of total amino acids in the soy sauces fermented with xylem sap and gorosoe, with the addition of sea salt instead of water, were 2-fold and 1.4-fold greater than that of ordinary soy sauce, respectively. In the DPPH assay, the antioxidant effect of soy sauce fermented with bamboo sap and sea salt was higher than that of other samples. Sensory evaluation showed that the overall acceptability of soy sauce fermented with gorosoe and sea salt was best, among the samples tested.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.477-484
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• 2008

For the effective use of the conger eel by-products, such as head and frame, Tang, which is the Korean-type soup, from conger eel by-products (TCEB) was developed and its food component characterization was compared with that of commercial Chueotang, loach Tang. According to the results of viable cells and coliform group of TCEB heated at $115^{\circ}C$ for various times, the reasonable $F_0$ value was 8 min. The proximate composition of TCEB was 90.7% for the moisture, 4.8% for the protein, 2.6% for the lipid, and 1.5% for the ash. The extractive-nitrogen content of TCEB was 243.1 mg/100 g, which was higher than that of commercial Chueotang, 208.0 mg/100 g. The total amino acid content of TCEB was 4,310 mg/100 g and its major amino acids were glutamic acid (637.3 mg/100 g, 14.8%), glycine (409.1 mg/100 g, 9.5%) and alanine (404.4 mg/100 g, 9.3%). TCEB was not felt in the sensual fish odor and its sensual taste was good. The health functional properties for health of TCEB were 1.29 as a PF (protection factor) for antioxidative activity and 39.4% for angiotensin Ⅰ converting enzyme (ACE) inhibiting activity.

• Food Science and Preservation
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• v.14 no.6
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• pp.669-675
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• 2007

Quality characteristics of Kwamaegi (semi-dried saury) prepared by treatment of chitosan-ascorbate (CA) and vacuum drying at $40{\sim}60^{\circ}C$(VDK), and the effect of the Kwamaegi on serum lipid profiles and anti-oxidation-related enzyme activity in rats fed high fat diets were investigated. The preparation periods were $4.5{\sim}8.3$ hr in VDK, while naturally dried Kwamaegi (NDK) took 360480 hr. Total microbe contents of VDK and NDK were $0.2{\sim}0.5$ and 8.2 log CFU/g, respectively. There was no significant difference in amino-nitrogen content. Compared with NDK, the acid and peroxide value, and fishy flavor of VDK40 (dried at $40^{\circ}C$) were significantly lower, and the texture, color and overall acceptability were higher. In animal experiments, weight gain, content of LDL-cholesterol and lipid peroxide, activities of total (T) and O type (O) xanthine oxidase, and the O/T ratio (%) were significantly lower in the VDK40 diet group than in the NDK diet group. The content of HDL-cholesterol in the VDK40 diet group was higher than in the NDK diet group. These results suggest that preparing CA-treated Kwamaegi with vacuum-drying at $40^{\circ}C$ can be applied throughout the year, and may shorten preparation time and improve its microbiological safety and nutritional values.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1864-1871
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• 2013

The effect of additives on the quality of low salted doenjang was investigated during storage. Amylase activity gradually decreased during storage and protease activity decreased after four weeks. The number of yeast was lower in the mustard or ethanol added groups without a difference in bacterial count. The L- and b-values decreased gradually during storage with lower total color difference (${\Delta}E$) in garlic added doenjang. Gas production was reduced in the ethanol or mustard added groups. Titratable acidity and acid values were low in the ethanol and ethanol-garlic added ones. A reducing sugar content was higher in the groups with added additives. Ethanol decreased to the largest extent in mustard added doenjang. Amino-type nitrogen decreased in ethanol added doenjang, whereas ammonia-type nitrogen was low in the ethanol or mustard added groups. The taste, flavor, and overall acceptability of doenjang were significantly higher in the ethanol or garlic added groups than in the other groups.

• The Korean Journal of Food And Nutrition
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• v.25 no.3
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• pp.505-512
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• 2012

This study evaluated the quality characteristics of rice-doenjang prepared with Aspergillus oryzae MD05 and Bacillus subtilis HJ18-4. The physicochemical characteristics of rice-doenjang prepared with three types of meju, such as grain type(Rice 1), disc shape(Rice 2), and brick shape(Rice 3), were compared. We determined amino and ammonia nitrogen contents, protease and amylase activities, reducing sugar content, and total aerobic counts and lactic acid bacteria counts. The amino nitrogen and reducing sugar contents in all meju types gradually increased during fermentation. The amino nitrogen contents reached 151.5~200.0 mg%. Rice 3 were had the highest levels among the 4 types of rice-doenjang. After 42 days of fermentation, amylase and protease activity of Rice 3 were 366.57 and 94.26 unit/g, respectively, which were the highest levels among the 4 types of rice-doenjang. The total aerobic bacteria counts were not changed during 42-day fermentation. This results suggest that high quality characteristics of brick-shaped meju(Rice 3) were better than those of the other meju preparations.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1805-1812
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• 2012

The effects of red-potato on the physicochemical properties of kochujang were investigated during fermentation. The number of yeast and aerobic bacteria in kochujang increased up to 4 weeks of fermentation, then the yeast number slowly decreased. Amylase activities also increased after 2~4 weeks of fermentation with the addition of red-potato. The Hunter L-value of kochujang decreased sharply and the a-value increased through the addition of starch syrup, causing major changes in total color difference as the ratio of red-potato increased. There was a direct correlation between the amount of red-potato with water activity and titratable acidity. The oxidation-reduction potential of kochujang decreased sharply after 12 weeks of fermentation, and was lowered with the addition of red-potato. As the ratio of red-potato increased, reducing sugars and ethanol contents of kochujang increased in the later stage of fermentation, while the amino-type nitrogen content was lower. Sensory results showed that a final percentage of 2% red-potato in kochujang was optimal for taste and overall acceptability.