• Korean Journal of Microbiology
• /
• v.48 no.2
• /
• pp.147-155
• /
• 2012

To improve of the quality of Korea traditional wheat-rice wine (makgeolli) production, we used a rice fermentation starter (rice nuruk) made by inoculation of Rhizopus oryzae CCS01 which was isolated and selected from commercial nuruk. Amylase activity of a rice nuruk was 1.8-2.4 times higher than those of commercial nuruks. The best acceptability of wheat-rice wine in a sensory test was observed at 4 : 6 ratio of wheat-rice mash at experimental condition. During the fermentation period, pH of wheat-rice makgeolli made with a rice nuruk was higher compared to those made with commercial nuruks such as Sanseong, Jinju, and Songhak. Acidity of makgeolli mash was lower in case of using a rice nuruk and birx and alcohol production were higher compared to those of makgeolli mash using commercial nuruks. Highest alcohol production was observed at makgeolli mash using a rice nuruk and 12% of alcohol was produced at fermentation end. These results suggest that production of a new type of wheat-rice makgeolli using a rice nuruk was possible.

• Korean Journal of Food Science and Technology
• /
• v.33 no.3
• /
• pp.366-372
• /
• 2001

Volatile flavor components in the mash of Takjus prepared by using Aspergillus oryzae nuruk were identified by using Gas Chromatography and Gas Chromatography-Mass Spectrometry. Twenty-four esters, 21 alcohols, 10 acids, 9 aldehydes and 4 others were found in the mash of Takju. Thirty six components including 13 esters and 12 alcohols were detected in the beginning of fermentation. Twenty nine components were more detected after second day of fermentation and 68 components were detected after 12 days of fermentation. Thirty five flavor components including 12 alcohols such as ethanol, 2-methyl-1-propanol, 3-methyl-1-butanol and benzeneethanol, 13 esters such as ethyl acetate, ethyl caprylate, ethyl butyrate and isoamyl acetate, 4 aldehydes and 6 acids were usually detected in the fermentation process. Ethanol was predominantly found in the range of $79.86{\sim}89.54%$ as a major component by using relative peak area. 3-Methyl-1-butanol, ethyl caprylate and benzeneethanol were some of the major volatile components through the fermentation respectively. Peak area of 2-methyl-1-propanol, 1-hexanol, 1-dodecanol, ethyl acetate, monoethyl butanoate, acetic acid and isobutylaldehyde among the same group were higher than other components depending upon fermentation time.

• Korean Journal of Food Science and Technology
• /
• v.32 no.3
• /
• pp.691-698
• /
• 2000

Volatile flavor components in the mash of takjus prepared by using Rhizopus japonicus nuruk were identified by using GC and GC-MS. Twenty-four esters, 19 alcohols, 9 acids, 10 aldehydes and 4 others were found in the mash of takju. Thirty nine components including 14 esters and 12 alcohols were detected in the beginning of fermentation. Seventeen components were more detected after second day of fermentation and 66 components were detected after 12 days of fermentation. Thirty eight flavor components including 12 alcohols such as ethanol, 2-methyl-1-propanol and 3-methyl-1-butanol, 14 esters such as ethylacetate, ethylcaprylate and isoamylacetate, 6 aldehydes and 5 acids were usually detected in the fermentation process. Ethanol was predominantly found in the range of 76.2149-92.1155% as a major component by using relative peak area. 3-Methyl-1-butanol, 2-methyl-1-propanol, ethyl caprylate, 2,3-butanediol and benzeneethanol were some of the major volatile components through the fermentation. Peak area of ethylacetate, diethyl succinate, octanoic acid, acetic acid and isobutylaldehyde among the same group were higher than other component depending upon fermentation time.

• Korean Journal of Food Science and Technology
• /
• v.37 no.6
• /
• pp.944-950
• /
• 2005

Volatile flavor components of Takjus mash prepared using Aspergillus kawachii nuruk were identified by GC and GC/MS. Twenty-two esters, 20 alcohols, 10 acids, 8 aldehydes, and 3 others were found in Takju mash. Thirty two components including 13 esters and 13 alcohols were detected at beginning of fermentation. Thirteen more components were detected after second day of fermentation, and 63 additional components after 12 days of fermentation. Twenty nine flavor components including 12 alcohols such as ethanol, 3-methyl-1-butanol, 2-methyl-1-propanol, and benzeneethanol, 12 esters such as ethyl acetate, ethyl caprylate, and ethyl butyrate 3 aldehydes, and 2 acids were detected during fermentation. Major volatile components detected during fermentation included 3-methyl-1-butanol, ethyl caprylate, and benzeneethanol. Peak areas of 2-methyl-1-propanol, 1-hexanol, 2, 3-butanediol (D.L), 1-dodecanol, 2-phenylethyl acetate, ethyl acetate, and monoethyl butanoate were higher than those of other components depending upon fermentation period.

• Applied Biological Chemistry
• /
• v.19 no.3
• /
• pp.155-161
• /
• 1976

The say sauce koji where made use of different kinds of seed koji were used to brewing of soysauce. The pure, complex and bacteria contaminated seed koji were used in this experiment, And the euzyme activity, Micrflora, chemical composition and TN-solubility ratio of each soysauce mash during the fermentation periods were measured respectively. The results obtained were as follows. 1. The neutral and alkali protease activity of each soysauce mash were decreassed in the process of fermentation period. In this case the activitities of protease in the bacteria contaminated koji were remarkably decreased. 2. The microflora in one ml of soysauce mash showed the tendency of increase in process of fermentation period. The increase in bacteria contaminated seed koji group was remarkable. 3. The content of total nitrogen, amino-N and ammonia-N in soysauce during the course of fermentation were increase. And alcohol, reducing sugar and pure extract contents in soysauce were also increased in the former stage of fermentation, but in the latter stage of fermentation decreased. 4. Though the content of ammonia-N in bacteria contaminated seed koji group was high, the pH value was low in comparison with the others. 5. Pure seed koji group were shown the most effective in the result of total nitrogen solubility ratio and sensual test, while the bacteria contaminated seed koji group was the worst.

• Journal of the Korean Society of Food Culture
• /
• v.11 no.4
• /
• pp.497-506
• /
• 1996

Fermentation characteristics and quality changes of the typical Korean traditional alcoholic beverages (Kwahaju, Sokokju, Baikhaju, Samhaeju and Hosanchun) were investigated during fermentation and after aging, respectively. They were prepared by their own brewing methods with respect to the same contents of rice and Nuruk (Korean-style bran koji). The consumed total sugar content of the alcoholic beverages (Sokokju, Baikhaju, Samhaeju and Hosanchun) which were brewed with the multiple input steps of seed mash and raw material (ABMIS) was higher than that of the alcoholic beverage (Kwahaju) which was brewed with the single input step (ABSIS). The pH values of all the beverages were similar and were ranged from 3.2 to 3.6. The acidity of ABMIS were lower than that of ABSIS, but alcohol concentration of ABMIS were higher. The fermentation period of the alcoholic beverages with triple input steps was the longest among them. The inner temperature and microbial growth in all the beverages increased at each of input steps of the raw materials. Fusel oil content of ABMIS was lower than that of ABSIS. Major components of the fusel oil were iso-amyl alcohol, iso-butanol, n-propanol, ethyl acetate and acetaldehyde, and its minor components were methanol and n-butanol. The results on quality changes of the alcoholic beverages after aging showed increase of alcohol in ABMIS, but decrease of sugar and acidity. Fusel oil contents of Kwahaju and Samhaeju decreased to be ranged from 3.1% to 13.9% after aging, but those of Sokokju, Baikhaju and Hosanchun increased to be ranged from 10.9% to 23.0%. Sensory evaluation of ABMIS showed better scores than that of ABSIS. It was suggested that the brewing method with multiple input steps of seed mash and raw material was one of the methods to increase fermentation efficiency for brewing the Korean traditional alcoholic beverages.

• The Korean Journal of Food And Nutrition
• /
• v.26 no.1
• /
• pp.78-84
• /
• 2013

To reproduce the brewing process of Hongkuk-ju and to identify the functional properties of it, Hongkuk-ju was brewed using different additions of Hongkuk (100%, 90%, 70%, 50%) and Nuruk (0%, 10%, 30%, 50%). The quality elements, including pH, total acidity, reducing sugar content, alcohol content and pigments (yellow, red, monacolin K and citrinin), were measured. The pH values of Hongkuk-ju showed a slight difference (pH 4.08~4.58) right after the $1^{st}$ stage mash; further, the pH on all groups (H1, H2, H3 and H4) in the terminal of the $2^{nd}$ stage mash (9 days in fermentation) were similar, ranging approximately at pH 3.70. The total acidity change did not show a difference directly the $1^{st}$ stage mash (nearby 0.2 %); however, it began to show a slight difference at the terminal of the $2^{nd}$ stage mash between the range of 0.69~0.76%. The residual reducing sugar of the content was decreased with the increased Nuruk content. The alcohol concentrations of the treatment brew with Nuruk ranging from 12.3% to 13.7% were higher than Hongkuk on its own. The yellow and red pigment contents of Hongkuk-ju ranged from 7.2~8.8 O.D. units (yellow pigment) and from 4.4~5.1 O.D. units (red pigment). The production of monacolin K and citrinin was the highest (9.48 mg/kg and 10.14 mg/kg) when the treatment solely brewed Hongkuk. The concentration of Nuruk and the preparation of the seed mash from it were critical factors compared to the treatment of rice in brewing Hongkuk-ju.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.26 no.1
• /
• pp.35-39
• /
• 2012

Sweet potato soju(SPS) has been made by vacuum distillation because sweet potato contains much fibrous materials which give high density to sweet potato mash. Generally, the SPS made by vacuum distillation has soft flavors and tastes. If the viscosity of sweet potato mash could be decreased by degradation enzyme, the process and production of SPS making by the method of vacuum distillation may be simplified and easier to distil the fermented sweet potato. Because the fibrous materials of sweet potato contains pectin with methoxyl group, methanol can be produced by fibrous degradation enzyme. For appling the fiber degradation enzymes to sweet potato mash for making SPS, the enzyme should be needed to degrade fibrous material without producing methanol. Special two fibrolytic enzymes are selected from 26 kind of commercial enzymes for the simplified and easier production of sweet potato soju by vacuum distillation, The selected enzyme A and X can degrade the fibrous material pectin of sweet potato without producing methanol. Although the different companies have produced the enzymes, same cellulase has been prepared from Trichoderma. reesei. The viscosity of sweet potato mash treated by the enzymes is decreased by 3 times with comparison to the viscosity of sweet potato mash of control group. The methanol concentration in the vacuum distilled SPS treated with the enzymes is 0.16%. The concentration is similar to that of commercially distilled SPS(0.15%). The result may suggest that the selected cellulases, A and X, can be used to make SPS by vacuum distillation.

• Applied Biological Chemistry
• /
• v.13 no.2
• /
• pp.171-180
• /
• 1970

The yeasts in the soy sauce mash were isolated and identified, and they were classified by coloring with the treatment of TTC(2, 3, 5, triphenyltetrazolium chloride) agar and counted in process of time. The results obtained were as follows: a) The number of ordinary and osmophilic yeasts in 1 ml. of the soy sauce mash showed a tendency to be increased from the mashing to the mature stages and to decrease in the aging stages: $127{\times}10^3$ immediately after mashing, $83{\times}10^3$ 1 month after, $356{\times}10^3$ 3 months after, $1250{\times}10^3$ 6 months after and $65{\times}10^3$ 2 years after mashing in the case of ordinary yeasts, and 0 after mashing, $40{\times}10^3$ 1 month after, $81{\times}10^3$ 3 months after, $358{\times}10^3$ 6 month after and $23{\times}10^3$ 2 years after mashing in the case of osmophilic yeasts. b) 50 strains of yeasts were isolated from the soy sauce mash optionally in process of fermentation period, and they were identified as 7 genera and 18 species: 10 strains of Saccharomyces rouxii, 1 strain of Saccharomyces marxianus, 3 strains of Saccharomyces rosei, 1 strain of Saccharomyces fermentati, 6 strains of Saccharomyces mellis, 1 strain of Saccharomyces acidifaciens, 1 strain of Saccharomyces pastori, 3 strains of Pichia polymorpha, 2 strains of Hansenula anomala, 1 strain of Hansenula saturnus, 2 strains of Hansenula suaveolens, 5 strains of Nadsonia fulvescens, 8 strains of Debaryomyces hasenii, 1 strain of Debaryomyces nicotianae, 1 strain of Debaryomyces kloeckeri, 2 strains of Torulopsis sake, 1 strain of Torulopsis holmii and 1 strain of Candida pelliculasa. c) Distribution of yeasts according to the fermentation period was as follows: i) Saccharomyces rouxii, Saccharomyces marxianus, Saccharoymces rosei, Pichia polymorpha, Debaryomyces hansenii, Torulopsis sake, Candida pelliculosa, Debaryomyces nicotianae, Nadsonia fulvescens, Hansenula suaveolens and Hansenula saturnus were found in the early stages of fermentation. ii) Saccharomyces rouxii, Saccharomyces rosei, Saccharomyces fermentati, Saccharomyces mellis, Saccharomyces pastori, Hansenula anomala, Saccharomyces acidifaciens and Debaryomyces hansenii appeared in the mature stages. iii) Saccharomyces rouxii, Saccharomyces mellis, Nadsonia fulvescenes, Dedaryomyces hansenii, Debaryomyces kloeckeri, Torulopsis sake and Torulopsis holmii were distributed in the aging stages. d) TTC white yeasts were found in abundance in the early stages of fermentation and TTC red yeasts appeared more than 50 per cent in the mature and aging stages. e) The yeasts belonging to Saccharomyces mellis and Saccharomyces pastori were classified as TTC red yeasts, Saccharomyces acidifaciens were reel pink, Hansenula saturnus Debaryomyces kloeckeri, and Torulopsis holmii were pink, Saccharomyces marxianus and Nadsonia fulvescens were white and the others were the same as the description in the previous report. Saccharomyces rouxii ware classified for the most part as TTC red yeasts, and while some of them were red pink. f) Species of yeasts in the soy sauce mash were similar to those in the soy sauce koji, but the latter were not osmophilic and in the former case, the osmophilic yeasts were increased in process of fermentation period.

• Korean Journal of Food Science and Technology
• /
• v.27 no.1
• /
• pp.134-140
• /
• 1995

Four different mashes using traditional methods in Korea such as Andong soju, Moonbaeju, Leekangju and Jindo hongju, were prepared for distilled liquor. The changes of pH, total acid, reducing sugar, total sugar, alcohol, solid content and ${\beta}-amylase$ activities in their mashes were studied during fermentation. Ethanol content of mashes were increased to the range of $8.8{\sim}11.2%$ after 16 days of fermentation. The group which was brewed by the first addition of mash showed higher ethanol content than the other group which was not added the ones. Total acid content of mashes increased to $0.59{\sim}1.10%$. The total sugar content was decreased to $6.70{\sim}8.94%$, and that of Leekangju type was lower than that of other fermented mashes. Reducing sugar content was in the range of $0.62{\sim}6.42%$ at the initial fermentation and decreased to $0.09{\sim}0.30%$ after 16 days of fermentation. Soju was obtained by distillation of each fermented mashes using the modified traditional Togori. After distillation of mashes, pH was increased and total acid was reduced. Sugar(3.58%) and solid(1.17%) in Leekangju were found to be leached from the mixture of pear, ginger, cinnamon, honey and curcuma rhizome.