• Journal of the Korean Society of Food Culture
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• v.25 no.6
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• pp.770-778
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• 2010

Bamboo leaf powder was added to Jeolpyun to increase the neutraceutical effects and storage period. The bamboo leaf powder was added to rice flour at ratios of 0, 4, 6, 8, and 10% (w/w), and they were treated with aqueous malt extract to extend storage. The Jeolpyun was stored at $20^{\circ}C$ for 72 hr, and the physical and sensory characteristics were evaluated. As a result, the crude fat, crude protein, moisture, crude ash and total dietary fiber contents in bamboo leaf powder were 4.36, 11.29, 3.37, 7.33, and 65.57%, respectively. The Hunters L, a, and b values decreased significantly as the amount of bamboo leaf powder increased; however, the a and b values increased during storage. The paste property setback values decreased with the malt extract treatment and with increasing amounts of bamboo leaf powder. In a sensory analysis, hard texture strength in the malt extract and bamboo leaf powder treatment groups was less than that in the control during storage. The Jeolpyun prepared with malt extract and no bamboo leaf powder was the most accepted by consumers. Although adding bamboo leaf powder resulted in less consumer acceptance except for the flavor attribute, adding 4% and 8% bamboo leaf powder resulted in better consumer acceptance for texture, taste, and overall acceptance than that of the control. In a microbial analysis, adding bamboo leaf powder resulted in fewer mold colonies. In conclusion, adding 4% bamboo leaf powder and malt extract to Jeolpyun improved its storage properties.

• Microbiology and Biotechnology Letters
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• v.51 no.2
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• pp.147-156
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• 2023

Tetragenococcus halophilus CY54, an isolate from jeotgal, grows best in media with 5% NaCl and can grow at 18% and higher salt concentration. Three different doenjang samples were prepared with multiple starters including T. halophilus CY54. TBZA doenjang was prepared with T. halophilus, Bacillus subtilis, Zygosaccharomyces rouxii and Aspergillus oryzae. BZA doenjang was prepared with the same 3 starters except T. halophilus. KACC doenjang was prepared with a single starter, B. subtilis KACC16750. During 16 weeks of fermentation at 25℃, the viable counts were maintained in the range of 7-8 log CFU/g in all 3 samples. As fermentation progressed, pH decreased and titratable acidity (TA) gradually increased. Crude protein contents decreased slightly. TBZA doenjang showed higher amino-type nitrogen (ANN) and volatile basic nitrogen (VBN) contents, and KACC doenjang showed higher ammonia-type nitrogen (AMN) content. TBZA doenjang showed higher fibrinolytic and protease activity than other doenjang samples. Metabolites analyses by GC/MS showed that doenjang samples were separated from each other by partial least squares-discriminant analysis (PLS-DA) analysis. Seventeen major metabolites involved in the differences between samples were identified and they included organic acids, amino acids, sugars, fatty acids and alcohols. TBZA doenjang showed higher contents for most metabolites responsible for flavor and taste of fermented foods including doenjang. These results showed that T. halophilus could be useful as a starter for doenjang and can improve the product quality by accelerating the fermentation processes.

• Journal of Microbiology and Biotechnology
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• v.33 no.10
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• pp.1337-1350
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• 2023

Caproic acid is a precursor substance for the synthesis of ethyl caproate, the main flavor substance of nongxiangxing baijiu liquor. In this study, Clostridium butyricum GD1-1, a strain with high caproic acid concentration (3.86 g/l), was isolated from the storage pit mud of nongxiangxing baijiu for sequencing and analysis. The strain's genome was 3,840,048 bp in length with 4,050 open reading frames. In addition, virulence factor annotation analysis showed C. butyricum GD1-1 to be safe at the genetic level. However, the annotation results using the Kyoto Encyclopedia of Genes and Genomes Automatic Annotation Server predicted a deficiency in the strain's synthesis of alanine, methionine, and biotin. These results were confirmed by essential nutrient factor validation experiments. Furthermore, the optimized medium conditions for caproic acid concentration by strain GD1-1 were (g/l): glucose 30, NaCl 5, yeast extract 10, peptone 10, beef paste 10, sodium acetate 11, L-cysteine 0.6, biotin 0.004, starch 2, and 2.0% ethanol. The optimized fermentation conditions for caproic acid production by C. butyricum GD1-1 on a single-factor basis were: 5% inoculum volume, 35℃, pH 7, and 90% loading volume. Under optimal conditions, the caproic acid concentration of strain GD1-1 reached 5.42 g/l, which was 1.40 times higher than the initial concentration. C. butyricum GD1-1 could be further used in caproic acid production, NXXB pit mud strengthening and maintenance, and artificial pit mud preparation.

• Microbiology and Biotechnology Letters
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• v.26 no.6
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• pp.551-557
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• 1998

Whole soybean cereal was fermented with four Aspergillus strains in pilot meju fermentation system. The pH range of the product was 7.40~7.98, the contents of reducing sugar and amino-nitrogen were 0.04~2.78%, 178~309 mg%, respectively and that of free fatty acid ranged 2.67~5.05%. The components of the amino acid, organic acid, free sugars and fatty acid showed distinctive patterns among four groups of fermented soybean cereals. Amylase activity and carbohydrate degradation rate of A. usami was higher than other strains. But protease and protein degradation rate, lipase and lipid degradation rate were similar in four strains. The odor concentrates of soybean cereals fermented with Aspergillus strains were different from Bacillus strains. Especially, pyrazine components, the main and common flavor chemicals in Bacillus strains, were not determined in this study and Aspergillus specific components were 9-methyl-acridine, dl-limonene and 2,3-butanediol. Soybean paste, made from A. oryzae fermented soybean cereal, showed excellent sensory evaluation.

• Food Science and Preservation
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• v.22 no.4
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• pp.545-552
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• 2015

This study investigated the quality characteristics of popped rice Doenjang prepared with different Bacillus strains (Bacillus subtilis KACC 15935, and Bacillus subtilis HJ18-9). The changes in the enzyme activity (protease, cellulase, and ${\alpha}$-amylase), amino-type nitrogen and ammonia-type nitrogen contents, and the reducing sugar were investigated during the fermentation period. Enzymes such as protease, cellulase, and a-amylase plays an important role in the changes in composition of nutrients, and in flavor and taste of popped rice Doenjang. Protease activities of the popped rice deonjang fermented with different Bacillus strains (control, B. subtilis KACC 15935, and B. subtilis HJ18-9) was in the range of 171.77-185.97 unit/g at the beginning of fermentation, and there were no significant differences among the samples. On the other hand, the protease activity in popped rice Doenjang fermented with B. subtilis HJ18-9 increased significantly up to $248.77{\pm}4.53unit/g$ at the end of fermentation (p<0.05). Cellulase activity and a-amylase activity of popped rice Doenjang in HJ18-9 was higher than these of other samples. After 56 days of fermentation, amino-type nitrogen in popped rice deonjang fermented with control, B. subtilis KACC 15935, and B. subtilis HJ18-9 increased significantly up to $174.99{\pm}3.70$, $166.59{\pm}1.40$, $225.39{\pm}3.70mg%$, respectively (p<0.05). These results suggested that B. subtilis HJ18-9 was a suitable starter for the preparation of soybean paste.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.3
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• pp.215-223
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• 2012

This study was conducted to prepare canned skipjack tuna Katsuwonus pelamis in the mixture of isotonic beverage and tomato paste (ST-S) for use as a health food. An analysis of the time-temperature profile and viable cells showed that a reasonable F0 value for ST-S preparation was 4 min. The proximate composition of ST-S was 76.8% moisture, 20.2% crude protein, 0.8% crude lipid, 1.7% ash and 0.5% carbohydrate. The calorie content of ST-S was 94.8 kcal, which is 47.4% lower than that of commercial canned skipjack tuna in oil (ST-O) and 2.2% lower than that of commercial chicken breast in water (CB-B). The total amino acid content of ST-S was 18.54 g/100 g, which is 31.4% lower than that of ST-O and 7.9% lower than that of CB-B. The major amino acids in ST-S were aspartic acid and glutamic acid. An enrichment effect due to such minerals as phosphorus, potassium and iron would be expected on consuming 100 g of ST-S. The major fatty acids in ST-S were 16:0 (27.4%), 18:1n-9 (14.3%) and 22:6n-3 (27.8%), which are different from those in ST-O and CB-B. The major free amino acids in ST-S were glutamic acid (8.1%), histidine (38.6%) and its related dipeptide, such as anserine (15.7%). In an evaluation of taste, flavor and color, ST-S was found to be superior to ST-O and CB-B.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.2
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• pp.279-290
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• 2010

Sensory analysis and quality properties were performed on post-aged doenjang (fermented soybean pastes) in order to elucidate the contribution of citrus, green tea and cactus powder to their sensory evaluation. The doenjang added citrus fruits, green tea and cactus powder used a concentration of 0, 3 and 7% (w/w) at 4, 20, $30^{\circ}C$ respectively and analyzed the proximate composition, pH, salt, mineral and amino acid contents after 60 days. Moisture and protein changes during ripening did not show any significant difference. The pH showed lower in the doenjang added citrus and cactus powder than no added soybean paste. The glutamic acid content of doenjang added citrus fruits showed a little decreasing value although there were no differences between samples with various addition contents. Sensory evaluation of doenjang showed that there were no significant differences in preference in the case of added green tea and cactus powder; However, the flavor significantly increased doenjang added 3% citrus powder at $30^{\circ}C$. These results showed that the preference of doenjang containing 3% citrus powder was superior to green tea and cactus powder.

• Applied Biological Chemistry
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• v.43 no.1
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• pp.29-33
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• 2000

This study was carried out to investigate the effect of glutaminase added to Doenjang, Kochujang and Kanjang in manufacturing. The consequential changes of L-glutamic acid and amino nitrogen contents were periodically analysed during aging. L-Glutamic acid contents in Kochujang, Doenjang and Kanjang aged for 45 days increased to 671.8%, 298.1% and 193.4% with glutaminase and also increased to 363.1%, 159.2% and 35.7% as compared with those without glutaminase. The 0.01% addition of glutaminase to Kochujang made L-glutamic acid content increased more than 3 times. The increase ratio of amino nitrogen was 216%, 120.8% and 84.5% in Kochujang, Kanjang and Doenjang with glutaminase which aged for 45 days, respectively. The effect of glutaminase added was the greatest in Kochujang. It increased to 35.7%, 8.4% and 40.3% as compared with those without glutaminase. The results of sensory evaluation showed that the products were favorably affected in taste, flavor and acceptability by glutaminase added.

• Applied Biological Chemistry
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• v.24 no.1
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• pp.21-28
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• 1981

Brewing method and quality of 15 samples of traditional Kochuzang in Junrabook-do area were investigated. Average combination ratio of glutinous rice: Meju (soybean Koji): red pepper powder was 2 : 0.7 : 1.1. In order to improve the taste of Kochuzang, some amount of natural soysauce was added in the Kochuzang at early stage of fermentation. Average content of sodium chloride was 7.32%; amino nitrogen, 123.3%; total sugar, 31.9%; reducing sugar, 19.4%; ethyl alcohol, 1.13% and the activity of acid protease was 0.07; liquefying amylase, 9.67 and saccharogenic amylase was 15.82. Five samples were selected as excellent Kochuzang through sensory evaluation. These samples were similarly strong in hot and sweet taste with alcoholic flavor, glossy surface and brownish red color.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.94-99
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• 2001

Kochujangs(fermented hot pepper-soybean paste) were prepared either using traditional meju (koji for kochujang) or controlled meju fermented by pure isolates (P-1, P-2), which were screened from traditional meju collected at Sunchang area. The isolates were characterized for their superiority on amylase and protease activities, and overall flavor of the culture on cooked soybean. Bacterial cell counts were not different in all treatments of kochujang during fermentation. The mold counts of each treatment dropped to undetectable level after 40 and 60 days of fermentation, respectively. Heat treatment($60^{\circ}C$, 15 min) before fermentation stopped gas formation and had no effect on bacterial cell count, but the growth of yeast was depressed. Total accumulative volume of gas produced during kochujang fermentation was depended on load of yeast in kochujang and the kochujang using P-2 koji produced least amount of gas among all treatments. The amylase and protease activities of kochujang were not significantly different among traditional and controlled kochujangs.