• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.532-538
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• 1994

In order to investigate the lowering effects of in vitro enzymatic hydrolysis by the treatment of chymotrypsin, trypsin, pancreatin, or protease from Aspergillus oryzae on the antigenicity of whey protein(WPI) against rabbit anti ${\beta}-LG$ antiserum, competitive inhibition ELISA(cELISA) and passive cutaneous anaphylaxis(PCA) test using guinea pig were performed. The results of cELISA showed that the monovalent antigenicity of the whey protein hydrolysates(WPH) to the antiserum was decreased to $10^{-1.7}{\sim}10^{-4.1}$ and less by the hydrolysis. Especially, the antigenicity of OUP(hydrolysate by protease from Asp. oryzae with preteatment of pepsin) was found almost to be removed. By the heterologous PCA the polyvalent antigenicity of the WPH was decreased to $1/2{\sim}1/128$ and less. Especially, the polyvalent antigenicity of OUN(hydrolysate by protease from Asp. oryzae without preteatments) was found almost to be removed, although OUN did not have so high degree of hydrolysis(DH) or so low monovalent antigenicity (reduced to $10^{-3.2}$). Therefore, this result was assumed to come from effective destruction of antigenic determinants on ${\beta}-LG$ in WPI, not to produce polyvalent antigenic peptides that are closely associated with induction of allergy. This finding suggested that WPH prepared by the treatment of microorganic protease from Asp. oryzae would be a material for hypoallergenic infant formula due to the removal of the polyvalent antigenicity of ${\beta}-LG$, the major milk allergen in WPI.

• The Korean Journal of Food And Nutrition
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• v.6 no.1
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• pp.1-7
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• 1993

19 Samples of koji-starters using in brewing were collected from Korea and Japan, and then 31 strains of koji-molds were isolated from them. After Identification of the Isolate, rice koji was made with each strains, and its saccharogenic activity, dextrogenic activity, proteolytic activity, acid Producing ability, browning reaction and flavor were tested. Among 31 strains of isolates, 10 strains were Identified as Asp nwamori var. kawachii, 18 strains as Asp. oryzae, 3 strains as Asp. usamii mkt. shirousamii. The koji-starters made in Korea were composed of single species of koji-mold with same strain, but those made in Japan were composed of the mixture of different two species or the mixture of different 2 ∼4 strains in same species. Judging from amylolytic and proteolytic ability by species, Asp. awamori var. kawachii H1, I1 and 11, Asp. owsae J2, L2, M2, P3 and P4, and Asp. usamii writ. shirousamii S1 were better than the others. Mold strains isolated from Korean koji-starters were much lower in amylolytic or proteolytic activity than those from Japanese koji-starters. The typical characteristics for the 3 species of koji-molds were that Asp. awamori var. kawachii was strong in acid producing ability, but week in amylolytic and proteolytic ability, that Asp. owzae had strong amylolytic activity and good aroma, but produced little amount of acid, and that Asp. usamii mut. shirousamii had strong Proteolytic activity but some off-flavor.

• Korean Journal of Microbiology
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• v.9 no.4
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• pp.155-162
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• 1971

A comparison of dextrinogenic amylase activities in the Asp. niger group was made with their crude and ethanol dialized enzymes before and after heating at high temperature (60-$65^{\circ}C$). The results obtained are as follows ; 1. THe dextrinogenic amylase activity of crude enzymes of Asp. kawachii and Asp. foetidus was strong, but Asp. phoernicis, Asp. carbonarius and Asp.japonicus showed weak activity. The others showed medial grades of activity. 2. The ethanol dialized enzymes of Asp. kawachii, Asp. foetidus and Asp. japonicus was very sesitive to high temperature (60 or $65^{\circ}C$) and their enzymatic activities were diminished greatly. The others did not show diminution of enzymatic activity at 60 or 65.deg.C, but diminished greatly at 70 or $75^{\circ}C$. 3. The ethanol dialized enzymes of the Asp.niger group heated to 65.deg.C was more sensitive at pH 6.0 and 6.5 than at pH 4.5, 5.0 and 5.5. 4. Tested strains in the Asp.niger group were subdivided into 4 subgroups by their dextrinogenic amylase activities before and after heating at 60 or $65^{\circ}C$. The first group showed a medial grade of activity before heating and no diminution of their enzymatic activities after heating. Asp. niger, Asp.pulverulentus, Asp. awamori and Asp. usmii were included in this group. The second group had strong enzymatic activity before heating, but diminished greatly after heating. Asp rawachii and Asp. phoenicis were included in this group. The fourth group showed very weak enzymatic activity before heating, and was inactivated easily by heating. Asp.oryzae of the Asp. flavus group showed a very strong dextrinogenic amylase activity before heating. After the heat treatment, however, its enzymatic activity was diminished greatly.

• Korean Journal of Food Science and Technology
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• v.22 no.2
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• pp.221-226
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• 1990

Fish flesh of Alaska pollack containing 5% of corn starch were fermented with 8 strains of mold and monitoring of their flavor characteristics, acceptability, nucleotides and their related compounds, amino acid compositions were conducted. All strains were grown vigorously on fish flesh media and formed their characteristic spores with unique flavor by strains. Amino type nitrogen $(NH_2-N)$ content of fermented fish flesh (FFF) were 25-26 times higher than that of raw flesh and 6-15 times higher in extractable nitrogen (Ex-N) content . The strains which produce more ADP (Adenosine 5'-diphosphate) in FFF also showed much higher level of IMP (Inosine 5'-monophosphate) and GMP (Guanosine 5'-monophosphate) content than that of raw flesh. Amino acid composition were differ by strain but lysine was generally highest and arginine, glutamic acid, leucine and alanine in order In review of sensory evaluation , total content of nucleotides, $NH_2-N$, Ex-N and amino acid compositions, suitable strains for fish flesh fermentation were Aspergillus oryzae KFCC 11371, Asp. oryzae KFCC 32343, Penicillium roqueforti KFCC 11269 and Asp. quercinus.

• Journal of Preventive Medicine and Public Health
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• v.9 no.1
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• pp.77-86
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• 1976

This study was attempted to know that the interactions of various fungi, and methionine and $MgSO_4$ introduced as the substrate of culture media for fungi were affected to produce aflatoxins by Asp. flavus. 5 different fungi were isolated from the fermented soybean mash and were cultured in Chemically Defined medium (C. D. media) and soybean mash at $25^{\circ}C$ for 10 days. (1) It was confirmed that Asp. flavus produced aflatoxins in the C. D. medium and soybean mast, but that Asp. niger, Asp. oryzae, Asp. awamori and Asp. terreus did not produced them respectively. (2) Asp. flavus cultured with Asp. niger did not produce aflatoxins in C. D. medium, but produced in soybean mash, in other hand, Asp. flavus with other fungi except Asp. niger produced aflatoxins in C. D. medium and soybean mash. (3) The growth of fungi were more prosperous in the seperate culture than in the mixed culture. (4) In the C. D. medium added 20% of cultured medium of Asp. niger, Asp. flavus did not produce aflatoxins but other cultured medium did not prohibit the production of aflatoxins by Asp. flavus. (5) On the contrary, $MgSO_4$ increasing the productivity of aflatoxins by Asp. flavus in the C. D. medium, methionine known as one of precursor of aflatoxins did not affected the increasing productivity with significance.

• Applied Biological Chemistry
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• v.42 no.2
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• pp.111-115
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• 1999

This study was attempted to develop technique of masking the pungent odor of chonggugjang using two-stage fermentation method with mixed pure cultures. Cooked soybeans were fermented with Lactobacilli or Aspergillus oryzae at $38^{\circ}C$ for 36 hrs, and then re-fermented with Bacillus subtilis for 12 hrs. The volatile compounds of chonggugjang were obtained with a SDE(Simultaneous steam Distillation and solvent Extraction) system and the extracts were identified by GC and GC-MS. The experimental results revealed the presence of 35 volatile compounds in control chonggugjang(only Bacillus subtilis inoculation). Among them, the major volatile compounds were 2,5-dimethyl pyrazine, 2,3,5-trimethyl pyrazine and 2-methyl pyrazine. Twenty-nine kinds of volatile compounds were in chonggugjang prepared by two-stage fermentation method with Lactobacilli and Bacillus subtilis(II), and major volatile compounds were identified to be 2,3,5-trimethyl pyrazine and 2,5-dimethyl Pyrazine. In chonggugjang(Asp. oryzae and then Bacillus subtilis inoculation(III)), the contents of hexadecanoic acid and 2-methyl pyrazine were patricularly high and the main components of chonggugjang fermented with rice straw(IV) were 2,5-dimethyl pyrazine, 2,3,5-trimethyl pyrazine etc. In conclusion, the flavor compounds such as 2, 5-dimethyl pyrazine, 2,3,5-trimethyl pyrazine and 2-methyl pyrazine were increased by the inoculation of Lactobacilli or Asp. oryzae, where as unpleasant odor components-butyric acid and valeric acid were decreased. Compared with volatile compounds of chonggugjang made from different soybean cultivars, the flavor compounds (2-methyl pyrazine 2,5-dimethyl pyrazine 2,6-dimethyl pyrazine 2,3-dimethyl pyrazine 2-acetyl pyrazine 2,3,5-trimethyl pyrazine 2-ethyl-3,5-dimethyl pyrazine) of chonggugiang prepared with Sinpaldalkong were high.

• The Korean Journal of Food And Nutrition
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• v.25 no.2
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• pp.253-258
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• 2012

This study was conducted to investigate the effects of different active gluten and rice Nuruk(Asp. oryzae, Asp. kawachii rice Nuruk) levels on the quality properties of steamed rice breads. Enzyme(amylase and acidic protease) activity of Asp. oryzae rice Nuruk is higher than Asp. kawachii rice Nuruk. Among the loaf volume of active gluten that were tested (10, 13, 15 and 17%) an active gluten loaf volume of 15% produced the best steamed rice bread. As a result of the loaf volume test steamed rice bread with rice Nuruk was decreased than steamed wheat bread. Regarding color, all treatments produced significant differences. The L value was decreased in steamed rice bread more than in steamed wheat bread, and a and b values were increased, respectively. Hardness, gumminess and chewiness of SRB-2, 3, 4 were lower than SWB-1 but springiness were higher. According to the sensory evaluation of steamed rice bread, color, flavor, and uniformity of pores were the highest in the steamed wheat bread, and the chewiness and texture were good in the steamed rice bread containing added active gluten and rice Nuruk. In this study, addition of rice Nuruk in steamed rice bread did not increase loaf volume, but had an advantage for overall desirability.

• Journal of Applied Biological Chemistry
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• v.52 no.3
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• pp.109-115
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• 2009

The gene encoding a putative aspartate aminotransferase in Xanthomonas oryzae pv. oryzae (Xoo) was cloned using PCR technique. The gene was ligated with pET-21(a) vector containing His6 tag and expressed in E. coli BL21(DE3). Affinity purification of the recombinant aspartate aminotransferase with Ni-NTA resin resulted in one band by SDS-PAGE analysis. The purified enzyme showed a molecular weight of 43 kDa, as expected. The enzyme was the most active toward L-aspartate as an amino donor, indicating that the purified enzyme is one of aspartate aminotrans-ferases exist in Xoo. Optimal activity of the enzyme was observed at around pH 7.5 and stability was much higher at alkaline pH rather than acidic pH values. The enzyme was considerably activated by the presence of manganese ion, showing about 157% of control activity at 1.0 mM.

• Applied Biological Chemistry
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• v.41 no.7
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• pp.500-504
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• 1998

The enzymatic transgalactosylation of L-ascorbic acid was investigated to synthesize a chemically stable form of L-ascorbic acid by using commercially available ${\beta}-galactosidases$. Among various enzymes examined, Aspergillus oryzae ${\beta}-galactosidase$ was found to be formed the derivative of ascorbic acid in a high yield from ascorbic acid and lactose. The reaction product was isolated by ion exchange chromatography on a $Dowex\;1\;{\times}\;8$ (Cl - form) resin and Toyopearl HW-40S gel chromatography. The product was identified as $6-O-{\beta}-_D-galactopyranosyl-_L-ascorbic\;acid$ on the basis of various experimental results, viz., UV, IR, $^1H-NMR,\;^{13}C-NMR$ and mass spectral data.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.1
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• pp.53-61
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• 2014

In this study, we investigated the production process and the chemical composition of saccharogenic mixed grain beverages (SMGBs). Various SMGBs were prepared through saccharification with Aspergillus (A.) oryzae CF1003 (A), A. acidus KACC46420 (B), Rhizopus (R.) delemar KACC46149 (C), R. oryzae KACC45714 (D), R. oryzae KACC46148 (E), A~E mixed strains (F), A. oryzae CF1001 (G), A. acidus CF1005 (H) and A+H mixed strains (I)-starter at $53^{\circ}C$ for 24 hours. The saccharogenic power of the strains was higher in samples F and G. The soluble solid ($^{\circ}Brix$) of SMGBs were the highest in Sample C. The moisture, crude protein, crude lipid, and crude ash content of various SMGBs showed a range of 77.9~80.7%, 3.7~7.5%, 0.37~0.97% and 1.81~7.47%, respectively. The viscosity of various SMGBs were in the range of 60~528. Further, free amino acid contents of SMGBs were in the range of 347~1,352 ${\mu}g/$ 100 g, respectively. From these results, we could secure the possibility and basic information for the development of SMGBs products. For future studies, we need to improve the taste and functionality of the products.