• Korean Journal of Microbiology
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• v.5 no.2
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• pp.55-60
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• 1967

Studies on the changes of methanol content in the manufacturing process of apple wine and apple brandy. The results from the studies of transition and changes of methanol content in the fermentation of wine and brandy from Korean apple, Kugkwang and Iwai are as follows. 1) Pectin, the source of methanol, can be extracted as dregs more than 85% of its in the process of pressing to get juice. 2) In the process of fermenting wine, the occurence of methanol depends on the condition of the apple itself (i.e. species, freshness, change in quality, or corruption). It seems that the insoluble pectin in the fresh apples changes into the soluble pectin as time goes by. 3) The heating treatment of fresh apples produced more methanol compared with nonheating treatment. 4) The content of methanol in apple brandy can influence free methanol content in mash pulp.

• Korean Journal of Microbiology
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• v.7 no.2
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• pp.45-56
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• 1969

The rapid deterioration of fermented rice-wine, called Tak Joo and Yak Joo, is one of the serious problems for brewing and marketing in Korea. In this study the biochemical and microbiological investigations have been performed for extension of shelf-life of the rice-wine by the method of combined heat and radiopasteurization. Major microflora in this wine is proved as Saccharomyces cereoisiar, which is destroyed by h-at treatmznt ($70^{\circ}C$, 10 min.) combined with gamma-irradiation of 240 K, rads doses. The changes of chemical constituents of them were investigated during the storage period at room temperatures of summer days($33^{\circ}C$). The results of sensory test for gamma-irradiated rice-wine with lower doses show no significant unfavourable off-odor nor color change compared with the fresh rice-wine. Therefore, it is revealed that the combined process makes possible extension of shelf-life of fermented rice-wine in markets without any deterioration and loose of its particular tastes at least for three weeks.

• KSBB Journal
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• v.30 no.1
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• pp.27-32
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• 2015

The current investigation was carried out to explore the possibility of submerged fermentation of Saccharina japonica as sole substrate using Aspergillus oryzae. In this study we used 2% S. japonica powder as fermentation media for A. oryzae. Fermentation period was optimized by monitoring the fermented sample at regular intervals for a period of 7 days. Results found that a fermentation period of 5 days was effective with maximum desirable characteristics such as total sugar, total phenolic and flavonoid contents. Under optimum fermentation period, fermented extracts showed enhanced antioxidant activity as determined by different assays such DPPH radical scavenging, ABTS scavenging and phosphomolydenum assay. This study provides the information for the enhancement of bioactive molecules in an eco-friendly manner and also paves way towards the development of wide range of seaweed-based functional foods.

• Korean Journal of Microbiology
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• v.10 no.2
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• pp.51-68
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• 1972

The aim of the sutdy is to collect a variety of wild yeasts from different regions in Korea and in different seasons and to account for the natural patterns of regional and seasonal variation that they display. From the specimens collected in this study, more useful strains are expected to be discovered, which can be cultivated and utilized fro industrial development. The study attempts to determine the degree to which utilizable yeasts can be applied in brewing, confectionary, baking, the manufacture of medicine, and as feed yeast. Such findings would contribute not only to the development of academic research, but would also be important in obtaining raw material that can be applied in our daily lives and in industrial development in response to the demands of the times.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.78-84
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• 2004

In order Nuruk to improve the quality of millet wine, a traditional Jeju cereal wine, yeasts and molds were isolated from 35 kinds of Nuruk collected nationwide. Isolated strains were screened for saccharification of starch and brewing of millet wine. Fermentation characteristics of millet wine with different types of Nuruk were also investigated. The average number of microbial populations in the Nuruk were $6.4{\times}10^5{\sim}4.5{\times}10^7\;cfu/g$ for molds and $1.4{\times}10^4{\sim}7.7{\times}10^7\;cfu/g$ for yeasts. Among the 169 strains of molds and 103 strains of yeasts, 16 strains were screened for saccharifying activity on starch as a substrate, and one yeast strain was screened for the brewing of millet wine. A8-3, supposed as Aspergillus sp., showed the highest enzyme activities of glucdamylase, ${\alpha}-amylase$ and xylanase while B23-3 strain, supposed as Rhizopus sp., showed the highest saccharifying activity. A10-4, supposed as Saccharomyces sp., showed the highest level of weight loss from $CO_2$ evolution, sugar and alcohol tolerance during fermentation. When the Nuruk was made after inoculation with the selected strains, saccharifying activity was higher for the co-cultivation of A8-3 and B23-3 than individual cultivation of each strain. Similar saccharifying activities were shown in both disc-type and pellet-type Nuruk. It was suggested that pellet-type Nuruk could improve fermentation yield. The collected Nuruk consisted of $10{\sim}13%$ moisture, $55{\sim}70%$ total sugar, $10{\sim}18%$ crude protein, $0.2{\sim}1.0%$ crude fat and $1.8{\sim}2.1%$ ash. The Nuruk made in this study was composed of $12{\sim}15%$ moisture, $61{\sim}71%$ total sugar, $15{\sim}20%$ crude protein, $0.4{\sim}1.5%$ crude fat and $1.1{\sim}1.5%$ ash.

• Korean Journal of Food Science and Technology
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• v.46 no.1
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• pp.25-32
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• 2014

This study aimed to analyze the general ingredients and volatile compounds of ipguk (koji) and nuruk soju distilled under reduced pressure (RP) or atmospheric pressure (AP) conditions. After the secondary brewing process, soju made using ipguk had a final fermentation alcohol content of $18.0{\pm}0.6%$, whereas soju made using nuruk reached $14.3{\pm}1.7%$. The level of succinic acid was the highest in ipguk soju ($7,685.33{\pm}34.97$ ppm), but nuruk soju also showed a high level of succinic acid ($5,945.79{\pm}76.30$ ppm) after its final fermentation. In an analysis of fusel alcohol content, the level of n-propanol in ipguk soju (389.10-397.27 ppm) was similar under different RP (50 cm Hg and 60 cm Hg) and AP conditions ($80^{\circ}C$ and $90^{\circ}C$). Under RP and AP conditions, the isoamyl alcohol/isobutanol (A/B) ratio was similar, ranging from 1.32-1.35. In ipguk soju distilled under RP conditions of 50 cm Hg and 60 cm Hg, the amount of the toxic component, acetaldehyde, was 8.59 and 9.27 ppm, respectively. Under AP conditions, the amount of acetaldehyde in ipguk soju distilled at 80 and $90^{\circ}C$ was 9.80 and 10.63 ppm, respectively, indicating that the amount of acetaldehyde did not differ depending on the distilling method used. These results suggest that the liquor distilled from the mash produced using ipguk under RP conditions may be of a higher quality.

• Applied Biological Chemistry
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• v.13 no.3
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• pp.219-222
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• 1970

Riboflavin in the various materials which used for Takju brewing was determined and its quantitative changes in the Takju mashes which were mashed with polished rice and wheat flour respectively using Nuruk only for enzyme source, and with wheat flour and corn powder respectively using Nuruk and Koji, were checked at 24 hours intervals during the whole brewing period. The results obtained were as follows. a) The riboflavin contents in 100 grams of each materials were: Polished rice $46.9{\gamma}$ Wheat flour $67.3{\gamma}$ Corn powder $73.9{\gamma}$ Nuruk $169.0{\gamma}$ Koji of wheat flour $87.1{\gamma}$ Koji of corn powder $84.4{\gamma}$ b) About 30 to 40 percent of riboflavin in the polished rice, wheat flour and corn powder were losed by steaming at 10 pounds for 50 minutes. c) Riboflavin content in the plots used Nuruk only was decreased during 3 days after mashing and then increased markedly after 5 days and, more or less, decreased after 6 days. Quantitative changes of riboflavin in the plots used Nuruk and Koji showed a rugged curve without decreasing in early stages, and its content was also increased markedly 5 days after mashing and then decreased a little after 6 days. d) Approximately $82{\gamma}$ of riboflavin was determined in 100ml. of the ripened mash of the rice plot and $72{\gamma}$ in the wheat flour plot in the case of using Nuruk only. $88.6{\gamma}$ of riboflavin were determined in 100ml. of the ripened mash of the wheat flour plot and $83.6{\gamma}$ in the corn powder plot in the case of using Nuruk and Koji. e) It was assumed that $28.8{\gamma}$ to $41{\gamma}$ of riboflavin were contained in 100 ml. of finished Takju of the two plots used Nuruk only and 33.6 to 44.5${\gamma}$ in the both two plots used Nuruk and Koji. f) About $47.3{\gamma}$ of riboflavin were determined in 100 grams of Takju cake of the rice plot and $66.2{\gamma}$ in the wheat flour plot used Nuruk only, and $62.9{\gamma}$ in the corn powder plot and $64.5{\gamma}$ in the wheat flour plot used Nuruk and Koji.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1579-1587
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• 2014

This study aimed to determine the quality characteristics of fermented wine using Nuruk according to the type of aging container (jar or stainless container) and aging time. Alcohol analysis was initiated at 40.4~39.3%, and alcohol contents in the jar and stainless container decreased as aging time increased. Volatile acid content slightly increased in the reduced pressure (RP) jar and stainless container and showed a different result in the atmospheric pressure (AP) container. Amount of acetic acid did not change either in the jar or stainless container as aging time increased. In the case of 2-thiobarbituric acid (TBA), RP was lower than AP after distillation, and TBA value did not change much either in the jar or stainless container. In the case of fusel alcohol by aging time, n-propanol content did not increase either in the jar or stainless container as aging time increased. Iso-butanol content was reduced in the jar but did not change in the stainless container. In the AP container, more aromatic components were measured on the 180th day of aging time than after distillation. High boiling point aromatic components increased in particular. In the stainless container, more aromatic components were generated on the 180th day of aging, but their amount was relatively lower than in the jar. In the jar aging sensory test, the sensory score at RP 50 cmHg was highest on the 180th day of aging. In the case of AP $80^{\circ}C$ liquor, sensory score on the 180th day was the most improved.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.714-720
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• 2013

We investigated the brewing and fermenting characteristics of makgeolli produced from high-yielding rice varieties. We used the high-yielding indica rice varieties, Anda and Dasan 1, and the japonica varieties, Deuraechan and Boramchan. Our results showed that the rice protein level was the highest in makgeolli produced from Anda ($7.5{\pm}0.2%$), while the amylose level was the lowest in makgeolli produced from the mid- to late-maturing japonica varieties (Deuraechan, $18.9{\pm}0.7%$; Boramchan, $18.9{\pm}1.4%$). Samples of makgeolli produced from Anda, Deuraechan, and Boramchan by using the Ipguk (Koji) method had an alcohol content of 16.6-17.4% on completion of fermentation. By contrast, makgeolli produced from Dasan 1 had an alcohol content of 14.3%; further, the makgeolli differed significantly in the sensory test and was scored as excellent regarding comprehensive preference. For makgeolli produced by using the uncooked rice fermentation method, samples produced from the indica varieties, Anda and Dasan 1, had lower alcohol contents (17.2% and 17.0%, respectively) and higher total acidity levels (0.33% and 0.31%, respectively) than did samples produced from the japonica varieties, Deuraechan and Boramchan (0.28% for both). In the sensory test, samples produced from Anda and Dasan 1 performed significantly better regarding scent, swallowing, and comprehensive preference.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.833-838
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• 2013

In this study, twelve strains of brewing fungi were individually cultivated on wheat extract broth (WEB), potato dextrose broth (PDB) and malt extract broth (MEB) in order to determine the microorganism with good culture characteristics as well as with amylolytic activity. The strain cultured in PDB exhibited mycelia production from 12.6 g/L (Rhizopus oryzae KACC 45714) to a maximum of 48.0 g/L (Aspergillus oryzae KACC 46959), which was 2.3~9.2 times lower than that of the strain cultured in WEB and 1.7~14.6 times lower than that of the strain cultured in MEB. Accorfing the results, We found that the commercial strains of A. oryzae Suwon, CF1001 and CF1003 had a higher dry cell mass than the wild-type strains KACC 46421, 46423, 46424 and 46959. For Rhizopus sp., the acidity levels in WEB, PDB and MEB were 0.12~0.47%, 0.22~1.0% and 0.16~0.68% (equivalent lactic acid concentration) respectively. For A. oryzae, the acidity levels were 0.06~0.11%, 0.03~0.04% and 0.06~0.08% (equivalent lactic acid concentration), respectively. Amylase enzyme from Rhizopus delemar KACC 46419 exhibited an enzyme activity of 0.013 U and 0.019 U in WEB and MEB cultures, respectively. The enzyme activity of the amylase enzyme from A. oryzae was 0.019~0.037, 0.017~0.033 and 0.028~0.046 U in WEB, PDB and MEB cultures, respectively.