• Food Science and Preservation
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• v.13 no.1
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• pp.88-94
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• 2006

This study was carried out to produce antimicrobial peptides from casein using various proteases. To examine whether the hydrolysis of casein would produce antimicrobial substance and the application as natural antimicrobial material, casein was hydrolyzed by five different proteases. The casein hydrolysate was fractionated with regenerated membrane filter (molecular weight cut-off 30,000 10,000 and 3,000) and antimicrobial activity was measured for each fraction. Antimicrobial activity appeared great in the fraction below 3,000 molecular weight The fraction was re-fractionated by high performance liquid chromatography and substance of main peak (retention time: 13.2 min) collected was used as a sample to measure antimicrobial activity. Among the casein hydrolysates produced by protease, antimicrobial activity was observed the greatest in hydrolysate treated with Aspergillus oryzae protease. The minimum inhibition concentrations of the Asp. oryzae protease hydrolysate were 1.0-1.5 mg/mL. This hydrolysate was a heat stable peptide since antimicrobial activity was maintained after treating with heat for 20 min at $121^{\circ}C$.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1976.04a
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• pp.182.3-182
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• 1976

A laboratory study was made for developing an fermentative method of producing conventional Korean soy sauce type of product from sandfish and defatted soy bean Koji of Aspergillus oryzae as raw material and enzme source, respectively. As an attempt to shorten the fermentation period, the admixture, consisting of pre-chopped sandfish slurry and the Koji of Asp. oryzae (100：15, wet fish weight/dry Koji weight) with added water equal to the fish weight (v/w), was first allowed, while being agitated at 450rpm, to undergo digestion for a 5 hour period at $50^{\circ}C$ with no added salt and then then, after adding 20％ salt (w/v), the hydrolysate mixture was ripened for up to 13 weeks at $30^{\circ}C$ and $45^{\circ}C,$ At intervals, an aliquot was withdrawn for determining microbiological, chemical and organoleptic changes taking place in the sandfish-defatted soy bean koji mixture during both digestion and ripening period.

• Preventive Nutrition and Food Science
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• v.6 no.2
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• pp.101-106
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• 2001

Alpha-amylase and glucoamylase activities were higher in koji with 40% water than that with 30 and 50% water, and A. oryzae exhibited very high alpha-amylase and glucoamylase activities compared to A. sojae and A. niger. Acidic, neutral and alkaline protease activities also showed higher activities in koji prepared with flour, Korean wheat powder and soybean powder with 40% water based on the weight of the sample. Alpha-amylase, acidic, neutral and alkaline protease activities of all the koji samples according to incubation periods increased until 3~4 days of incubation and maintained nearly the same level or slightly decreased after 5 days of incubation. The protease activities of A. oryzae and A. sojae showed nearly the same trend regardless of differences in substrate conditions and koji materials, but those of A. niger showed a lower activity than those of A. oryzae and A. sojae. These results suggest that the preparation of koji is possible with Korean wheat powder and soybean powder and A. sojae can be utilized as a new strain for fermented foods using soybean as the main materials to increase functional properties and produce products having a new taste and flavor.

• Applied Biological Chemistry
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• v.30 no.4
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• pp.345-350
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• 1987

Three lots of mejues were prepared with three different strains of Aspergillus oryzae, Bacillus natto, Bacillus subtilis and one was made by conventional method. The four different soy bean pastes were analyzed for compositions of free amino acids, sugars and organic acids during the period of fermentation. Amino nitrogen contents in the samples of A. oryzae were higher than others throughout the aging period. The amounts of each amino acids were varied markedly among the samples after 20-days, while glutamic acid, aspartic acid, lysine and phenylalanine were dominant in all samples after 90-days. Glucose contents were found to be in the range of $0.46{\sim}2.66%$ and other sugars of fructose, sucrose, rhamnose and maltose were less than 0.35%. The levels of total free sugar were relatively higher in the samples prepared with B. natto than others. Citric, lactic, malic, acetic and oxalic acids were identified, and the content of lactic acid was higher in the samples of A. oryzae, whereas citric acid was higher in conventional method.

• Korean Journal of Food Science and Technology
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• v.43 no.3
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• pp.334-340
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• 2011

Squid was fermented with fermentation accelerators to develop a natural complex seasoning. The quality properties of fermented squid were determined at different fermentation periods. Squid fermented with 10% Aspergillus oryzae koji for 10 days had the highest amino-N, acidity, and total viable cell content during fermentation periods, whereas volatile basic nitrogen content and pH were the lowest. Based on the amino-N content, squid with 10% koji fermented for 10 days was selected for further analyses. The inosine and glutamic acid contents of the fermented squid were highest innucleotide composition, their related compounds, and free amino acids, respectively. The $IC_{50}$ values of the fermented squid on DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging and ${\alpha}$-glucosidase inhibitory activities were 6.20 and 4.41 mg/mL, respectively. Based on the results of a sensory evaluation, the fermented squid seasoning was similar to other natural complex seasonings such as anchovy, cowmeat, and fisheries seasonings.

• Mycobiology
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• v.43 no.3
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• pp.258-265
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• 2015

The fungi on Meju are known to play an important role as degrader of macromolecule of soybeans. In order to elucidate the origin of fungi on traditional Meju, mycobiota of the air both inside and outside traditional Meju fermentation rooms was examined. From 11 samples of air collected from inside and outside of 7 Meju fermentation rooms, 37 genera and 90 species of fungi were identified. In outside air of the fermentation room, Cladosporium sp. and Cladosporium cladosporioides were the dominant species, followed by Cladosporium tenuissimum, Eurotium sp., Phoma sp., Sistotrema brinkmannii, Alternaria sp., Aspergillus fumigatus, Schizophyllum commune, and Penicillium glabrum. In inside air of the fermentation room, Cladosporium sp., Aspergillus oryzae, Penicillium chrysogenum, Asp. nidulans, Aspergillus sp., Cla. cladosporioides, Eurotium sp., Penicillium sp., Cla. tenuissimum, Asp. niger, Eur. herbariorum, Asp. sydowii, and Eur. repens were collected with high frequency. The concentrations of the genera Aspergillus, Eurotium, and Penicillium were significantly higher in inside air than outside air. From this result and those of previous reports, the origin of fungi present on Meju was inferred. Of the dominant fungal species present on Meju, Lichtheimia ramosa, Mucor circinelloides, Mucor racemosus, and Scopulariopsis brevicaulis are thought to be originated from outside air, because these species are not or are rarely isolated from rice straw and soybean; however, they were detected outside air of fermentation room and are species commonly found in indoor environments. However, Asp. oryzae, Pen. polonicum, Eur. repens, Pen. solitum, and Eur. chevalieri, which are frequently found on Meju, are common in rice straw and could be transferred from rice straw to Meju. The fungi grow and produce abundant spores during Meju fermentation, and after the spores accumulate in the air of fermentation room, they could influence mycobiota of Meju fermentation in the following year. This could explain why concentrations of the genera Aspergillus, Eurotium, and Penicillium are much higher inside than outside of the fermentation rooms.

• Microbiology and Biotechnology Letters
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• v.11 no.3
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• pp.241-248
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• 1983

Lupin seed was used to make Meju, the fermentation starter for Korean soybean sauce and paste in substitution for soybean and the fermentation characteristics were compared with those of soybean. Mejus were prepared by in-oculating Asp. oryzae on the cooked whole beans. The dried Mejus were used for making fermented bean sauce and paste by mixing with brine and subsequent ripening for 4 weeks. In general the protease activity and amylase activity-during ripening were higher in lupin seed Meju than those of soybean Meju. The increase in protease activity correlated to the increase in $\alpha$-amino nitrogen content of the fermented paste and sauce. The development of dark-brown color of the sauce during ripening faster with lupin seed Meju compared to soybean Meju. In sensory evaluation the flavor score of lupin seed sauce and paste was slightly lower than that of soybean products but the overall quality of fermented lupin seed sauce was acceptable.

• Korean Journal of Microbiology
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• v.7 no.4
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• pp.159-166
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• 1969

It is necessry to develop and strengthen the activity of enzymic source which in low applied for maggerley brewing as an amylolytic and proteolytic starter, recently in this country the active and strong enzymic starter is required for the better brewing and to substitute another starch material for the present wheat flour. In this study, manufacturing method the strong enzymic source have been developed and established with use of raw wheat bran plus fungal strains of Rhizopus sp. and Aspergillus usamii the culture of starter. The results on experimental the activities of enzymic sources (stater) are as following ; 1. Method of making the enzymic source (starter) is to cultivate the strains of Asperguillus orzyae, Asp. kawachii, Asp usamii and Rhizopus sp. in the acid treated raw or heatboiled wheat bran. 2. The saccharogenic pwoer (S.P.) of enzymic source which consisted of raw bran plus fungi and cultured in it is generally stronger than those of heat-boiled bran plus fungi, the strongest power was shown in the culture of Rhizopus plus raw bran, and the next other is in mixture of Asp.usamii and Rhizopus on raw wheat bran. 3. The most strong alpha amylase activity was expressed in the plot of Asp.oryzae on heat-boiled wheat bran, the next was in the culture of Rhizopus nad Aspergillus usamii on raw wheatbran. 4. The most vigourous acidic proteinase activity was expressed in the micture of raw bran plus Asp. usamii and Rhizopus those were independentlu cu;tured before mixing for neutral proteinase activity, it was shown in the mixed culture of Asp. usamii and Rhizopus on raw wheat bran, the msot active alkaline proteinase activity of enzymic source was found in the plot of raw bran material. 5. For poly-preptidase activity in pH 6.5 it is found that the culture of Rhizopus and Asp.usamii on raw bran was most active among them of enzymic sources. 6. Generally, it is concluded that culture of fungi on acid treated raw wheat bran is stronger in its activity than those of heat boiled wheat bran, especially the culture of Rhizopus nad Asp.usamii on raw bran exhibited the most vigorous and non-polarized activity for all aspects, so it is considered to be most desirable enzymic stater in Korean Maggerley brewing and this would be able to substitute brewing material for the present wheat flour because of its strong and wide hand activity of amylolytic and proteolytic action.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.343-350
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• 2002

This study was conducted to standardize the manufacturing process of doenjang. The preparation methods, kinds and levels of the ingredients were determined by the statistical surveys of literatures obtained from cooking books, scientific papers and doenjang manufacturing factories. The standardized preparation of fermentation methods of doenjang were classified into two large groups, that were traditional and modified (commercialized) methods. Most soybeans used in doenjang preparation were the large size. To prepare traditional doenjang, soybeans were cleaned, scaled and cooked for 2 hrs at atmospheric pressure. These cooked soybeans were crushed in water and molded as brick shape. The molded soybean was dried for 2 days in the air, hung up by rice straw and fermented for 30~60 days under natural environmental condition (called meju). Recently soybean grain meju that inoculated with Asp. oryzae also frequently used to make traditional doenjang. The fermented meju was brined with a ratio of meju : salt : water = 18.4 : 14.6 : 67.0 and the meju-brine mixtures were ripened for 2 months. When the meju-brine mixture was fully fermented, it was separated into liquid and solid parts. The crushed solid part was further ripened in a separated pottery for 60 days and become doenjang. The liquid part was filtered, boiled and used as soy sauce. In modified commercial doenjang preparation, soybeans were cocked by autoclaving and then cooled about to 3$0^{\circ}C$. Separately, steamed barley grains or wheat flour were inoculated with 0.2% Asp. oryzae and incubated for 3 days at 3$0^{\circ}C$ and mixed with the crooked soybeans, salt, and water (soybean : salt : starch : water = 39.8 : 12.5 : 22.6 : 25.1). These mixtures were ripened for 30 days at 3$0^{\circ}C$. It seems that the manufacturing process of traditional doenjang needs to be more industrialized, whereas, the commercial doenjang preparation is going to adapt the traditional processing method of doenjang.

• Applied Biological Chemistry
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• v.22 no.2
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• pp.65-90
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• 1979

This study was conducted to establish the brewing method which would be useful for the production of Kochuzang. Kojis, which were made from various materials and microorganisms under a covered condition, were investigated and compared. Yeasts (Saccharomyces rouxii and Torulopsis versatilis) were added to Kochuzang, and the enzyme activity, microflora, chemical composition, nitrogen content, alcohol content and free sugars of Kochuzang were investigated and analysed. The results obtained are as follows: 1. Koji making (1) Glutinous rice-soybean group was superior to glutinous rice group in the saccharogenic and liquefying amylase activities of three day-Koji. (2) Protease activity (acid, neutral and alkaline) of glutinous rice-soybean Koji, which was inoculated with Aspergillus oryzae A, was increased till the 5th day, while other groups showed maximum activity after the 3rd day. (3) The maximum cellulose activity of Aspergillus oryzae B-Koji and A-Koji was observed after the 2nd day and the 3rd day, respectively. High cellulose activity of Aspergillus oryzae B-Koji and A-Koji was respectively shown in glutinous rice group and glutinous rice-soybean group at maximum. (4) Compared with glutinous rice Koji, glutinous rice-soybean Koji gave larger number of yeast and aerobic bacteria. 2. Kochuzang Fermentation (1) Each Kochuzang group shoved different liquefying and saccharogenic amylase activities. The highest activities were generally shown in 10 to 40 days after mashing and remarkably reduced in the last stage of aging. (2) Protease activities of each group were strong in order of acid, neutral and alkaline protease. Especially acid protease showed highest activity at the 40th to 50th day Kochuzang. (3) Each group showed maximum cellulase activity in the 40th and 50th day-Kochuzang and then decreased. (4) Osmophilic yeast of yeast-added Kochuzang after one-month aging was distinctively outnumbered compared with non-yeast-added Kochuzang, but two groups were similar after two months. (5) Yeast-added group and non-added group gave almost the same number of halophilic lactic acid bacteria in Kochuzang, but the non-added group gave slightly larger number of aerobic bacteria than the yeast-added group. (6) Amino nitrogen contents in all test group were increased rapidly till the 60th day of Kochuzang aged. After that the contents were increased slowly. (7) Ethyl alcohol contents of 20day-fermented Kochuzang were high in order of Saccharomyces rouxii-added group, Torulopsis versatilis-added group, Saccharomyces rouxii and Torulopsis versatilis mixed group and non-yeast-added group. But all test group showed about 2% in ethyl alcohol content after 40days of aging. (8) Alcohol content in the 7 month-aged Kochuzang of all test groups was high in order of ethyl alcohol, n-butyl alcohol, n-propyl alcohol and iso-propyl alcohol. Torulopsis versatilis-added group had the highest value of ethyl alcohol, n-propyl alcohol and n-butyl alcohol. (9) Reducing sugar in Kochuzang was increased after 20 days of aging compared with the 10days-ferment. The reducing sugar content in Saccharomyces rouxii-added group was distinctively small compared with that of other groups, decreasing after 30days of aging. (10) Rhamnose, fructose, glucose and maltose were isolated from the 10 day fermented Kochuzang. Raffinose was also found after 300 days-aged group, and fructose content was high in the 300days-aged Kochuzang. However, glucose content was smaller than that of 10days-fermented Kochuzang. (11) For the organoleptic tests of Kochuzang, taste, flavour and color of yeast-added group were superior to the non yeast-added group. Especially the complex yeast group among the yeast added groups were the best of all. Yeast-added group after 300 days of aging took higher paint in flavour test than that of non-added group. Therefore, brewing method like complex yeast added group seems to be advantageous for short time brewing Kochuzang.