• The Korean Journal of Mycology
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• v.23 no.2 s.73
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• pp.161-175
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• 1995

Meju is a raw material used to make Korean soy sauce (Kanjang) and soybean paste (Doenjang), both of them rich in plant protein. The twenty-nine fungal and a bacterial species were identified from twenty-three traditionally homemade meju cakes. Out of them, only a few species were found to be involved in the actual fermentation process of meju; The other species were contaminants during the improper subprocesses of meju fermentation. The fungal floral successions were observed to be related to two physical and biochemical changes of meju cakes during meju fermentation: drying and heat releasing processes. The zygomycetous fungi were first observed to exist mainly during the first stage. Scopulariopsis brevicaulis was observed to grow on the surface of meju cakes and then to coexist with Bacillus megatrium in the inner part of meju cakes during the second stage. Based on the biochemical tests, the proteases secreted by the different microorganisms were involved in the degradation of soybean proteins with a mutual relationship. Also, zygomycetous fungi were speculated to be important microorganisms for inducing the second stage in the traditional Korean homemade meju.

• The Korean Journal of Community Living Science
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• v.12 no.1
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• pp.41-49
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• 2001

The purpose of this study was to investigate the preparation patterns of traditional fermented soybean products(jang) from the housewives living in Yangsan. 89.4% of the respondents used once a day, every meal and the frequency of eating was higher with getting older. 70% answered that the taste of their homemade doenjang was good, while only 2.5% were not be satisfied with their doenjang. According to the survey, 82.2% of the housewives used the meju made by the traditional method for jang preparation, of which perparation patterns showed remarkablely in the housewives living in the independent home. On the other hand, we could see that the amount of jang preparated one time in each home of Yangsan region was approximately 6∼10kg or 16∼20kg. The hard tasks of jang preparation were seasoning, storing and meju preparation. Especially, housewives living in the communal house had a difficulty in storing of jang. But most wants to continue to prepare jang by traditional method at home.

• Korean Journal of Food Science and Technology
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• v.8 no.1
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• pp.19-32
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• 1976

The laboratory Mejus as well as home-made Meju and improved Meju received from Korea were ripened in the brine for up to 8 months and the changes is the chemical composition during the process were determined and the differences between the types of Meju were compared. On the basis of the amino acid pattern, the changes in the protein quality of soybean during the process was evaluated. No significant changes in the general chemical composition of Meju were noticed during the ripening for 8 months. However, the nitrogen solubility of Meju increased for $13{\sim}29%$ to $66{\sim}78%$ during 8 month ripening of the Meju-brine mixture. The concentration of free amino-N to the total-N increased from $4{\sim}7%$ in Meju to $29{\sim}35%$ in the 8month ripened mixture. The concentration of amino-N to the total-N increased from $1{\sim}4%$ in Meju to $5{\sim}14%$ in the 8month ripened mixture and the changes varied with the type of Meju used. Remarkable changes in the amino acid pattern of soybean were occured during the ripening process. The concentration of methionine decreased to the half of original Meju during the first month of ripening. Arginine and histidine were destroyed rapidly by the ripening longer than 1 month. A considerable amount of ornithine was synthesized during the ripening. The amino acid pattern of Meju did change drastically during the ripening longer than 3 months and the changes varied with the type of Meju. The retention of the nutrients in soybean during 8 month ripening of the laboratory 3 month Meju in the brine was 49% for carbohydrates, 107% for crude fat, 93% for crude protein and 74% for the total amino acid. Histidine, arginine and methionine and 74% for the total amino acid. Histidine, arginine and methionine were the most damaged during the process, retaining only 25%, 27% and 49% of the contents in raw soybean, respectively, whereas lysine retained 79%. By the separation of the 8 month ripened mixture, approximately 60% of crude protein, all of crude fat and 80% of carbohydrates in the mixture were retained in soypaste. Soypaste contained higher concentrations of amino acids per 16gN compared to soysauce, except for lysine. The most limiting amino acid of the protein was the S-containing amino acids in all cases studied, whereas the second limiting amino acid varied from valine in soybean to threonine in most of Mejus and the brine mixtures, lysine in most of soypastes and tryptophan in some of soysauces. According to the protein quality evaluation made by the reference of the FAO provisional pattern of amino acid, the chemical score of raw soybean was 82, which was reduced to 77 by cooking and further reduced to $71{\sim}74$ by Meju fermentation. At the eighth month of ripening the chemical score of the Meju-brine mixtures were reduced to $51{\sim}66. After the separation, the chemical score of soypaste ranged from 60 to 71, whereas that of soysauce varied from 45 to 57. Generally, the products made from improved Meju recorded the highest score, whereas those made from homemade Meju showed the poorest protein quality. The essential amino acid index(EAAI) of the samples was similar to the chemical score, but it appeared to fit the overall changes in the amino acid pattern during the process better than the chemical score.

• Journal of the Korean Society of Food Culture
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• v.35 no.4
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• pp.342-350
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• 2020

This study examined the methods used in household doenjang (Korean soybean paste) production. Nine hundred forty-three responses were obtained using a nationwide, questionnaire-based survey (2018-2019) with non-probabilistic snowballing sampling. Consistent with previous studies, the respondents were primarily over the age of 50 years (97.1%) and female (97.9%). In addition to soybeans, the most used ingredients were red pepper (85.8%) and charcoal (85.5%), which most respondents obtained through direct farming (50.4-59.9%). Seasonal production occurred later in the higher latitude regions (Gyeonggi-do, Gangwon-do, Chungcheong-do) (p < 0.01), which have lower average temperatures, and the fermentation period was shorter in the lower latitude regions (Jeolla-do, Gyeongsang-do, Jeju-do) (p < 0.01), which have higher average temperatures. There were no significant regional differences in the season when doenjang was made, with most production occurring during January and February (81.1%). Most respondents (71.3%) made doenjang using homemade meju (soybean block used as a starter) in a traditional way to allow the microorganisms to be naturally inoculated. These results could be used as a basis for future research on topics such as starter development, standardized production, and safety of household doenjang.