• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.2
• /
• pp.250-255
• /
• 2001

Effect of molding temperature on the quality changes of extruded meju was studied. Meju was molded at 8$0^{\circ}C$, 6$0^{\circ}C$ and 4$0^{\circ}C$, and then stored at $25^{\circ}C$ with 50% of relative humidity for 30 days. The texture of the cooked soybean grain showed that the firmness and cohesiveness were increased, and consistency was decreased by decrease of molding temperature. The density of the meju molded at 8$0^{\circ}C$, 6$0^{\circ}C$ and 4$0^{\circ}C$ were 1.072g/mL, 1.079g/mL and 1.203g/mL, respectively. The meju molded at 4$0^{\circ}C$ had significantly higher density than those molded at 8$0^{\circ}C$ or 6$0^{\circ}C$. Also, delay of water evaporation, acidification, and rapid growth of fungal mycellium were observed on the sample with molding temperature at 4$0^{\circ}C$ during fermentation. Activity of amylase and protease, contents of total reducing sugar and amino nitrogen of 4$0^{\circ}C$-molded meju were represented lower level than those of 6$0^{\circ}C$ or 8$0^{\circ}C$-molded sample. Therefore, it was considered that the molding temperature was an important factor for meju fermentation and molding temperature of 6$0^{\circ}C$ or over would be acceptable.

• The Korean Journal of Food And Nutrition
• /
• v.19 no.4
• /
• pp.460-465
• /
• 2006

This study was conducted to investigate the isoflavone contents including daidzein and genistein in soy sauces made with whole grain soybean Meju(WGSM), comparing with defatted Meju(DM) du.ins fermentation. Total isoflavone contents in 2 soy sauces made with DM, Control and product A, increased with period of fermentation and were 15 and 4.3 times higher after 180 days of fermentation than on the day before fermentation respectively. Meanwhile, 2 soy sauces made with WGSM, product B and C, had the highest amounts with $20.53{\mu}g/g\;and\;19.52{\mu}g/g$ of isoflavones on the day before fermentation respectively, and then decreased with fermentation time. High amounts of isoflavones were detected in 20 days of fermentation of soy sauce which made with WGSM and wheat Meju(product D). Daidzein was the largest amounts in isoflavone contents, regardless of total or free isoflavone types. The level of daidzein increased with fermentation time in 2 soy sauces made with DM, Control and product A, whereas 2 soy sauces made with WGSM, product B and C decreased with fermentation time, instead of increasing of genistein contents.

• Korean journal of food and cookery science
• /
• v.14 no.5
• /
• pp.509-512
• /
• 1998

Changes in the contents of stachyose and raffinose were determined during soybean fermentation. ${\alpha}$-Galactosidase activities were also monitored in soybean and its fermented products. The stachyose contents were 31.8239 mg/g of soybean, 4.2217 mg/g of Meju, and 2.1184 mg/g of Doenjang. The raffinose contents were 2.6914 mg/g of soybean, 1.7413 mg/g of Meju, and negligible of Doenjang. ${\alpha}$-Galactosidase activities was distinct in soybean and Meju. They were 14.5954 units/mg protein of soybean, 13.1489 units/mg protein of Meju, and 1.9157 units/mg protein of Doenjang. The results suggested that the decrease of stachyose and raffinose contents in fermented soy products were due to the ${\alpha}$-galactosidase activity.

• Mycobiology
• /
• v.50 no.6
• /
• pp.408-419
• /
• 2022

Filamentous fungi that could be classified into Aspergillus flavus/oryzae were isolated from traditionally fermented meju commercially available in Korea. The samples were analyzed for aflatoxin B1 and ochratoxin A contamination by HPLC; however, no toxin was detected. In addition, fungal and bacterial metagenomic sequencing were performed to analyze the microbial distribution in the samples. The results revealed that the distribution and abundance of fungi and bacteria differed considerably depending on the production regions and fermentation conditions of the meju samples. Through morphological analysis, ITS region sequencing, and assessment of the aflatoxin-producing ability, a total of 32 A. flavus/oryzae strains were identified. PCR analysis of six regions with a high mutation frequency in the aflatoxin gene cluster (AGC) revealed a total of six types of AGC breaking point patterns. The A. flavus/oryzae strains did not exhibit the high amylase activity detected in the commercial yellow koji strain (starter mold). However, their peptidase and lipase activities were generally higher than that of the koji isolates. We verified the safety of the traditionally fermented meju samples by analyzing the AGC breaking point pattern and the enzyme activities of A. flavus/oryzae strains isolated from the samples. The isolated strains could possibly be used as starter molds for soybean fermentation.

• Applied Biological Chemistry
• /
• v.37 no.6
• /
• pp.421-426
• /
• 1994

This study was carried out to investigate the effect of $CaCO_3$ on the Chungkookjang Meju fermentation. B. subtilis was cultured on the Meju added 0, 0.01, 0.1, 1% $CaCO_3$, respectively, and the chemical composition, protease activity, amino acid and vitamin B complex were examined with fermentation time. The inner temperature of the $CaCO_3$ treatments during fermentation was increased as compared with the control group. Titratable acidity in Meju decreased as $CaCO_3$ concentration increased. And protease activity and amino-nitrogen content were however high in same order. The content of amino acid was on the increase in every treatments, it made no difference between $CaCO_3$, treatments and the control. Vitamin B complex content in the $CaCO_3$ treatments was increased than in the control. The 0.01% added treatment showed the highest amount of vitamin B complex content in all the treatments.

• Korean Journal of Food Science and Technology
• /
• v.30 no.4
• /
• pp.908-915
• /
• 1998

By using Korean native soybean, traditional meju was prepared in Chuncheon, Kangweondo according to the traditional process. Analysis of physico-chemical, enzymatic and microbiological changes during meju fermentation were carried out in order to obtain a basic information for industrial scale production of meju. The enviroments for natural meju fermentation were $10{\sim}15^{\circ}C$ and $60{\sim}70%{\;}RH$. Moisture content decreased from 59% to 11% (exterior section) and 19% (interior section). the pH of meju rapidly increased up to 8.5 at $33^{rd}{\;}day$ of fermentation and thereafter decreased down to 7.9 at $70^{th}{\;}day$ of fermentation. Souble protein content was 1.47% at initial stage and increased up to $6.31{\sim}7.34%$ at $33^{rd}{\;}day$ of fermentation. Amino nitrogen content was $460{\sim}770{\;}mg%$ at $70^{th}{\;}day$ of fermentation. the color of meju became gradually black and decreased in redness and yellowness. During the process, protease and lipase seemed to play an important role in the digestion of soy protein and fat. Acidic protease activity increased up to $135.9{\sim}152.4{\;}unit/g$ at $33^{rd}{\;}day$ of fermentation and were $181.3{\sim}272.6{\;}unit/g$ at $70^{th}{\;}day$ of fermentation. Lipase activity increased up to 6 unit/g (interior section) and 15 unit/g (exterior section) at $70^{th}{\;}day$ of fermentation. the viable cell count of meju was at the level of $10^8{\;}CFU/g$ during the overall fermentation period. Aerobic halophilic count was $1.51{\times}10^7{\;}CFU/g$ at initial stage and maintained $10^8{\;}CFU/g$ level during the process. Initial anaerobic cell count was $2.0^9{\times}10^4{\;}CFU/g$ and increased up to $10^5{\;}CFU/g$ level at 47 days. Yeast and mold counts were $10^4{\sim}10^5{\;}CFU/g$ for the fermentation period.

• Korean Journal of Food Science and Technology
• /
• v.39 no.3
• /
• pp.304-308
• /
• 2007

This research was conducted to investigate the changes in quality characteristics of meju made with 24-hour germinated soybeans according to fermentation time. The study confirmed that the amino nitrogen content immediately after soaking was 15.5 mg%, and the content rapidly increased in the beginning of the germination process and continued to increase to 312.9 mg% by 48 hours of fermentation. The number of fungi in the whole soybean meju made with 24-hour germinated soybeans was higher than the numbers of bacteria and yeast since the Aspergillus oryzae was inoculated artificially. The content of organic acids, in which the amount of citric acid was highest followed by tartaric acid and malic acid, increased with the fermentation process. The level of free amino acids in the whole soybean meju made from the 24-hour germinated soybeans increased rapidly with fermentation. The free amino acid content after 48 hours of fermentation (2,513.5 mg%) was 5.7 times higher than the content of the soaked germinated soybeans. The content of glutamic acid was highest followed by aspartic acid, lysine, leucine, and proline. The ratio of glutamic acid to the total free amino acids at 48 hours fermentation was 21.2% for the whole soybean meju. It was confirmed that the total isoflavone content, in which the content of genistein was highest followed by daidzein and glycitein, increased at the beginning of the fermentation process, but did not change thereafter.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.6
• /
• pp.849-856
• /
• 2009

In this study, dietary supplementations of Korean Meju, fermented soybean meal (F-SBM) by Aspergillus oryzae, and A. oryzae itself were evaluated on growth performance, feed utilization, immune responses and phosphorus availability in juvenile parrot fish, a marine aquaculture fish species. Four isonitrogenous and isocaloric diets were formulated to contain 8% soybean meal (control diet), 4% Meju (50% soybean meal was replaced by Meju), 4% F-SBM (50% soybean meal was replaced by F-SBM), or 0.08% A. oryzae itself. One of the four experimental diets was fed to triplicate groups of fish for 8 weeks. At the end of the feeding trial, no significant differences were found in growth performances and feed utilization. Red blood cell counts in the fish fed the A. oryzae diet were significantly higher than that of fish fed the control diet. The antioxidant activity in Meju diet was significantly higher than that of the control and A. oryzae diets. Fish fed Meju and F-SBM diets showed numerically higher antioxidant activity of serum compared to that of fish fed the control diet, even though it was not significant. Liver superoxide dismutase activity of fish fed the test diets was significantly higher than that of fish fed the control diet. The apparent digestibility coefficients of protein of fish fed all the diets were not significantly different. Phosphorus absorption was numerically increased in fish fed F-SBM and A. oryzae diets compared to that of fish fed the control diet. This study indicates that the fermentation process of soybean meal does not impair growth performance and feed utilization in parrot fish. The fermentation process could enhance the availability of phosphorus in soybean meal and non-specific immune responses of parrot fish.

• Food Science and Biotechnology
• /
• v.15 no.4
• /
• pp.549-554
• /
• 2006

To standardize a manufacturing method and improve the quality of traditional kochujang, eight-types of meju with different shapes (brick, grain) were prepared using Aspergillus oryzae (A.o) or Aspergillus sojae (A.s) alone or in combination with Bacillus subtilis (B.s). The physicochemical characteristics and enzyme activities of the various meju were compared during fermentation for 12 days at $28^{\circ}C$. The moisture content of both the brick- and grain-shaped meju were gradually decreased from an initial content of 50.47 to 54.89% to a content of 12.91 to 16.25% on day 12 of fermentation. The neutral protease activities of the brick-shaped meju ranged from $1.19{\pm}0.12$ to $1.25{\pm}0.28\;unit/mL$, and were similar for all treatments. The ${\alpha}$-amylase activities in A.s+B.s treatment of brick-shaped and grain-shaped meju were the highest, $11{\pm}0.6$ and $9{\pm}0.7\;unit/mL$, respectively. The ${\beta}$-amylase activities ranged from $1.53{\pm}0.01$ to $1.56{\pm}0.02\;unit/mL$, and were similar for all treatments. The amino type nitrogen content of A.o+B.s brick-shaped meju was the highest, $0.39{\pm}0.03%$. We confirmed that the brick-shaped meju prepared with A. oryzae and B. subtilis could be used to prepare traditional kochujang to improve the quality of the product.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.2
• /
• pp.268-274
• /
• 1998

The traditional kanjang has been prepared by mixing meju and 18% saline solution, and fermenting for 60 days. The traditional kanjang is very salty and inferior in flavor and taste comparing with commercial fermented soy sauce. To improve the quality of traditional kanjang, Zygosaccharomyces rouxii H-62, a flavor-related mutant, was inoculated during fermentation. It was found that the addition of Z rouxii helped to improve the organoleptic quaity of traditional kanjang. The optimal condition for preparing traditional kanjang was to use 5L of 15.5% saline solution per meju. Meju must be cut into 12 pieces to get a proper total nitrogen and pure extract content. The optimal fermentatin temperature was 3$0^{\circ}C$. The prepared kanjang contained over 0.8% total nitrogen and 6.0% pure extract after 60 days of fermentation.