• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.924-933
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• 1998

Kochujang, fermented hot pepper-soybean paste, was prepared by two common varieties of red pepper and natural fermented (NF) or pure cultured (PC) meju (soybean mass that is soaked, steamed, mashed and fermented by natural microflora or pure strain) and monitored their taste related component, enzyme activity and microflora during fermentation at $25^{\circ}C$ for 120 days for confirming possibility of kochujang fermentation control. The reducing sugars, amino type nitrogen (reference quality factor) and amino acid content in PC kochujang were 11.4%, 0.58% and 1,372.9 mg% respectively, 7.1%, 0.42% and 1,038.7 mg% in NF kochujang. It is concerned higher ${\alpha}-{\;}and{\;}{\beta}-{\;}amylase$ and, acid and neutral protease in PC kochujang during fermentation. The meju fermented by selected pure strain (A. oryzae CBU) can be applied to produced better quality of kochujang instead of natural meju.

• Journal of the Korean Society of Food Culture
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• v.34 no.4
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• pp.456-462
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• 2019

This study investigated the bread-making properties of rice bread supplemented with HPMC (hydroxypropyl methylcellulose) 1~3% and gluzyme (glucose oxidase), fungamyl (fungal ${\alpha}$-amylase) and pentopan (xylanase+hemicellulases) (0.0015~0.0090%). The viscoelastic properties of the dough with HPMC 1~3% were analyzed. When the rice flour was supplemented with HPMC 1~3%, the viscoelastic properties of the dough tended to increase as the amount of added HPMC was increased. The physicochemical characteristics of the rice bread with HPMC, gluzyme, fungamyl, and pentopan were analyzed. Supplementing the rice flour with HPMC, gluzyme, fungamyl, and pentopan had a significant effect on the volume (p<0.01) and specific volume (p<0.001) of the rice bread. Supplementing the rice flour with 3% HPMC and 0.0045% or 0.0090% pentopan had a significant effect on increasing the volume (p<0.01) and specific volume (p<0.001) of the rice bread. Supplementing the rice flour with 3% HPMC, 0.0023% gluzyme and 0.0015% fungamyl had a significant effect on increasing the volume (p<0.01) and specific volume (p<0.001) of the rice bread. These results suggest that supplementing the rice flour with HPMC, gluzyme, fungamyl and pentopan is effective for the production of rice bread.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.69-77
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• 2019

Screening microorganisms that can produce glucan hydrolases for industrial, environmental, and biomedical applications is important. Herein, we describe a novel approach to perform glucan hydrolase screening-based on analysis of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) spectra-which involves degradation of the oligo- and polysaccharides. As a proof-of-concept study, glucan hydrolases that could break down glucans made of several glucose units were used to demonstrate the MALDI-MS-based enzyme assay. First, the enzyme activities of ${\alpha}$-amylase and cellulase on a mixture of glucan oligosaccharides were successfully discriminated, where changes of the MALDI-MS profiles directly reflected the glucan hydrolase activities. Next, we validated that this MALDI-MS-based enzyme assay could be applied to glucan polysaccharides (i.e., pullulan, lichenan, and schizophyllan). Finally, the bacterial glucan hydrolase activities were screened on 96-well plate-based platforms, using cell lysates or samples of secreted enzyme. Our results demonstrated that the MALDI-MS-based enzyme assay system would be useful for investigating bacterial glucoside hydrolases in a high-throughput manner.

• Journal of Microbiology and Biotechnology
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• v.33 no.7
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• pp.926-933
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• 2023

Aspergillus oryzae KCCM 11372 was used to enhance the production of β-glucan using humidity control strategies. Under conditions of 60% humidity, solid-state fermentation (SSF) increased the yields of enzymes (amylase and protease), fungal biomass (ergosterol), and β-glucan. The maximum concentrations obtained were 14800.58 U/g at 72 h, 1068.14 U/g at 120 h, 1.42 mg/g at 72 h, and 12.0% (w/w) at 72 h, respectively. Moreover, the β-glucan containing fermented brown rice (β-glucan-FBR) extracts at concentrations of 25-300 ㎍/ml was considered noncytotoxic to 3T3-L1 preadipocytes. We then studied the inhibitory effects of the extracts on fat droplet formation in 3T3-L1 cells. As a result, 300 ㎍/ml of β-glucan-FBR extracts showed a high inhibition of 38.88% in lipid accumulation. Further, these extracts inhibited adipogenesis in the 3T3-L1 adipocytes by decreasing the expression of C/EBPα, PPARγ, aP2, and GLUT4 genes.

• Korean Journal of Organic Agriculture
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• v.26 no.1
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• pp.151-161
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• 2018

This study was designed to investigate the effects of multi-enzyme on diarrhea and immune responses of weaned pigs. A total 36 weaned pigs ($5.92{\pm}0.48kg\;BW$; 28 d old) were randomly allotted to 2 dietary treatments (3 pigs/pen, 6 replicates/treatment) in a randomized complete block design. The dietary treatments were a typical diet based on corn and soybean meal (CON) and CON with 0.1% multienzyme (Multi; mixture of ${\beta}-mannanase$, xylanase, ${\alpha}-amylase$, protease, ${\beta}-glucanase$, and pectinase). Pigs were fed their respective diets for 6 wk. Frequency of diarrhea, levels of packed cell volume (PCV), white blood cells (WBC), immunoglobulins, cortisol, tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), transforming growth $factor-{\beta}$ ($TGF-{\beta}$), and C-reactive protein (CRP) were measured. Multi group tended to decrease (p<0.1) diarrhea frequency than CON group during 2 wk after weaning. Lower values of PCV on d 3 (p<0.05) and d 7 (p<0.1) were found in Multi group compared with CON group. There were no significant differences on WBC number and immunoglobulin (Ig) M and A between Multi and CON groups. However, Multi group tended to increase (p<0.1) Ig G on d 7 than CON group. Moreover, Multi group showed modulated immune responses, indicated by decreased levels of cortisol (p<0.05) on d 7 and 14, $TNF-{\alpha}$ on d 3 (p<0.05) and d 7 (p<0.10), $TGF-{\beta}$ on d 2 (p<0.05) and d 7 (p<0.10), and CRP (p<0.10) on d 3 and 7 after weaning compared with CON group. Consequently, inclusion of multi-enzyme in diets for weaned pigs improved gut health and modulated immune responses of weaned pigs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.76-82
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• 2009

Wheat is the most widely cultivated cereal and an important source of dietary protein worldwide. Wheat allergy, defined as an adverse immunologic reaction to wheat, encompasses a broad spectrum of disorders with different pathomechanisms and clinical manifestation. The Nuruk, a traditional Korean Koji for brewing, was made with wheat flour and fermenting microbes such as bacteria, yeast and mold. The strains grown on Nuruk secrete various enzymes as amylase and protease. By the activation of such enzymes, starch and proteins in Nuruk are hydrolyzed to sugar and amino acid. Therefore, it is supposed to reduce allergic proteins in wheat. To study quality properties and degradation degree of allergenicity in Nuruk by fermentation, we investigated the changes of general ingredients and allergenicity in Nuruk during fermentation. Moisture contents was decreased from 24.2% to 13.6% during fermentation. Crude lipid and protein contents were gradually increased during fermentation. After 15 days of fermentation, reducing sugar and total sugar contents were reached its maximum level, and they were 27.45% and 39.00%, respectively. Acid and neutral protease activity were significantly increased during fermentation, but alkaline protease activity was not detected. ${\alpha}$-amylase activity was gradually increased and showed maximum level about 2,833.00 U/g after 15 days of fermentation. Glucoamylase activity was the highest level about 497.9 U/g after 10 days of fermentation. The increase of these proteolytic and saccharogenic enzyme activities will provide efficient condition for production of rice wine. Also, protein fractions were isolated from Nuruk, and degradation of these proteins during fermentation were confirmed by SDS-PAGE. IgE immunoblotting using patient's sera with wheat allergy was performed to confirm allergenic protein in Nuruk. These results as fermentation of Nuruk will provide a useful tool for developing safer wheat products to prevent wheat allergy.

• Food Science and Preservation
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• v.24 no.7
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• pp.975-982
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• 2017

Health of human intestine has deteriorated due to excessive stress and western diet. In this study, Vigna angularis was fermented by Bacillus subtilis KCCM11965P in order to develop prebiotic resource for improving bowel movement. The contents of ash and crude protein were $3.35{\pm}0.04%$ and $21.1{\pm}0.19%$ respectively. Vigna angularis extract (1, 3, 5%) were incubated with 3% (v/v) Bacillus subtilis KCCM 11965P for 0, 24, 48, and 72 h. Total bacterial numbers showed that the combination of 3% powdered seeds and 72 h incubation time was optimum condition for this experiment. Total polyphenol content increased from $0.18{\pm}0.010mg/mL$ in pre-incubation to $0.23{\pm}0.007mg/mL$ in post-incubation with the condition mentioned above. DPPH radical scavenging activity also increased from $36.1{\pm}6.0%$ to $63.6{\pm}5.2%$. Analysis of protease activity showed $2.69{\pm}0.003unit/mL$ in combination of 5% powdered seeds and 72 h incubation time. Amylase activity increased from $1.0{\pm}0.1unit/mL$ in pre-incubation to $26.0{\pm}0.2unit/mL$ in post-incubation. The analysis of free amino acids after incubation with Bacillus subtilis KCCM 11965P showed that leucine increased from 5.22 mg/L to 67.59 mg/L and tyrosine, one of non-essential amino acid also increased 10.08 mg/L to 259.35 mg/L by incubation with 5% powdered seeds. Most of organic acid were reduced by incubation for 72 h. These results suggest that Vigna angularis could be utilized most as a prebiotic resources.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.448-455
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• 2004

Changes in quality characteristics of Bijijang (fermented soybean curd residus) prepared at $35^{\circ}C\;and\;40^{\circ}C$ for 0, 12, 24, 36, and 48 hr were investigated. Acidity of Bijijang increased, whereas pH and Hunter's color values decreased during fermentation. Immediately after Bijijang preparation, ${\alpha}-and\;{\beta}-amylase$ activities were very low, ${\beta}-Amylase$ activity during fermentation increased rapidly, with those fermented at $40^{\circ}C$ higher than at $35^{\circ}C$. Neutral pretense activity was significantly higher than acidic pretense activity, and increased gradually after 12 hr. Change in total nitrogen content in Bijijang was insignificant, whereas contents of amino-type and water-soluble nitrogens increased significantly during fermentation. Major free amino acids of Bijijang were Arg, Pro, Glu, Thr, Ser, and Lys at initial fermenting stage, and, as fermentation progressed, contents of Cys, Met Glu, Ile, Leu, and Phe increased. Reducing sugar contents of Bijijang fermented at $40^{\circ}C$ were higher than those fermented at $35^{\circ}C$. Sucrose content decreased and glucose content increased. Glucoside (genistin and daidzin) contents decreased and aglycone (genistein and daidzein) contents increased during preparation of Biji and fermentation of Bijijang. Contents of free sugars and isoflavones were higher in Bijijang fermented at $40^{\circ}C$ than at $35^{\circ}C$. Based on these results, fermentation at $40^{\circ}C$ for 48 hr was determined to be optimum fermentation condition for Bijijang.

• 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.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.904-909
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• 1996

To investigate effects of sugars on the retrogradation of rice flour gels, sucrose and isomaltooligosaccharide (1, 2, and 5%, w/w on the flour basis were added to 50% Dongjinbyeo rice flour gels and stored at different temperature $(20^{\circ}C,\;4^{\circ}C)$ far 1, 3 and 6 days. Changes on the degree of retrogradation (DR) of these rice flour gels were measured by α-amylase-iodine method, DSC and X-ray diffractometry. DRs of rice flour gels increased over storage and showed a rapid increase up to 3 days and then decreased thereafter. DRs of rice flour gels with sucrose or oligosaccharide also increased rapidly until 3 day storage but these values were lower than those of rice flour gels without sugar. DRs of rice flour gels with oligosaccharide were lower than those of gels with sucrose. Changes in enthalpy of rice flour gels measured by DSC showed the same tendency with those in DRs of rice flour gels by ${\alpha}-amylase-iodine$ method, but varied with sugar levels.