• Korean Journal of Food Science and Technology
• /
• v.42 no.6
• /
• pp.727-732
• /
• 2010

The pH, acidity, color, amino acid, reducing sugar, total sugar, and alcohol contents of puffed millet powder supplemented with different concentrations of millet takju were investigated during 10 days of fermentation. The pH ranged from 4.06 to 4.58 at day 1 but decreased drastically to 3.55-3.64 at day 2. With the exception of day 1, a higher pH was observed with a higher concentration of puffed millet powder (p<0.05). Acidity tended to increase quickly over time, especially for the 0% sample after day 4 (p<0.05). The sudden increase of acidity at day 2 agreed with the pH decrease. A lower concentration of puffed millet powder resulted in a greater Hunter "L" value (p<0.05) and tended to show lower Hunter "a" and higher Hunter "b" values on the same day. Amino acids increased over time, and a higher concentration of puffed millet powder resulted in lower amino acid content on the same day after day 3 (p<0.05). After a rapid reduction in reducing sugar on day 2 (p<0.05), minimal differences were observed in the samples after day 4. The 75% puffed millet powder sample showed the highest reducing sugar content, except on days 8 and 9 (p<0.05). Total sugars decreased rapidly by day 3, and then either remained unchanged or decreased after day 4. Higher alcohol concentrations were observed with higher concentrations of puffed millet powder, except on day 1 (p<0.05).

• Journal of Environmental Health Sciences
• /
• v.46 no.3
• /
• pp.324-334
• /
• 2020

Objectives: This study was conducted to estimate the related health risk by investigating the content of biogenic amines (BAs) in commercial fermented alcoholic beverages. Methods: Ninety-seven samples, including takjus (34), fruit wines (26), distilled liquors (20) and beers (17) were purchased in Gangwon-do (Province) in 2019. The eight BAs (putrescine, cadaverine, spermine, spermidine, tyramine, β-phenylethylamine, histamine, and tryptamine) were analyzed by high performance liquid chromatograph (HPLC) after extraction (0.4 M HClO₄), pigment removal (carbon cartridge) and derivatization (1% dansylchloride). The health risk of exposure to BAs due to ingestion of commercial fermented alcoholic beverages was estimated as the margin of exposure (MOE). Results: Various BAs were detected in takju, fruit wine, distilled liquor and beer. Putrescine (not detected (ND)-12.60 mg/L), cadaverine (ND-5.45 mg/L), tyramine (ND-8.34 mg/L), β-phenylethylamine (ND-13.73 mg/L), histamine (ND-7.96 mg/L), and tryptamine (ND-19.00 mg/L) were found in takju. Putrescine (ND-15.34 mg/L), cadaverine (ND-7.90 mg/L), β-phenylethylamine (ND-3.06 mg/L), histamine (ND-9.68 mg/L), and tryptamine (ND-14.06 mg/L) were identified in fruit wine. Putrescine (less than limit of detection (

• Journal of Life Science
• /
• v.22 no.1
• /
• pp.110-116
• /
• 2012

Nuruk plays a significant role in the flavor and quality of Takju and Yakju, which are produced through saccharification and alcohol fermentation by various microorganisms. In this study, we identified microbial strains isolated from a plate count and PCR-denaturing gradient gel electrophoresis (DGGE) analysis targeting the 16S and 28S rRNA genes, in order to characterize bacterial and fungal diversity in Sansung Nuruk. The numbers of bacteria and fungi in Nuruk were $1.5{\times}10^9$ CFU/g and $2.2{\tims}10^8$ CFU/g, respectively. The 16S rRNA gene sequence indicated that the predominant bacteria in the isolates and PCR-DGGE profile of Nuruk were Kocuria spp., Pantoea spp., Lactobacillus spp., Pediococcus spp., Weissella spp., Staphylococcus spp., endophytic bacterium, uncultured Gamma-proteobacteria, uncultured Cyanobacteria, and Actinobacteria. Dominant bacteria from the PCR-DGGE profile were Pediococcous pentosaceus and uncultured Cyanobacteria. The 28S rRNA gene sequence indicated the predominant fungi in the isolates and PCR-DGGE profile to be Trichomonascus spp. Pichia spp., Torulaspora spp., Wickerhamomyces spp., Sacharomycopsis spp., Lichtheimia spp., Mucor spp., Rhizopus spp. Aspergillus spp., and Cladosporium spp. Dominant fungi from the PCR-DGGE profile were Pichia kudriavzevii and Aspergillus oryzae. The PCR-DGGE technique was used for the first time in this study to assess a microbial community in Nuruk and proved to be an effective protocol for profiling microbial diversity.

• Applied Biological Chemistry
• /
• v.18 no.1
• /
• pp.10-15
• /
• 1975

These studies were conducted to induce the available mutants in Takju yeasts by the irradiation of UV light. Two original strains(5-Y-5, 6-Y-6) using for irradiation of UV selected from 24 strains which were isolated from the Takju mashes And Nuruks collected from 12 local regions of Chungnam and Chungbuk provinces in Korea, and the irradiations to the yeasts with UV light were carried out at a distance 10-40cm from the sources of irradiation for 10-220 seconds. The purpose of this experiment is to report the effects of irradiating distances and times of UV light on the survival ratio of orginal yeasts, and the identification of two orginal yeasts and three mutants induced by the irradiation of UV light. The results were summarized as follows. 1) The effects of irradiating distances and times on the survival ratio on the yeasts were represented as follows. and acid productivity to the survival strains by the irradiation of UV light. The selected mutants were the strains 30-24, 40-27 which have more powerful fermentability about 10 percent than those of original strains and a strain 30-81 which have potential acid productivity. 3) The selected yeasts (5-Y-5, 6-Y-6) were identified to Saccharomyces cerevisiae by a taxonomic study of Lodder and the mutants(30-81, 40-27, 30-81) induced from above yeasts by the irradiation of UV light have almost same properties two orginal yeasts in the identical characteristics.

• Food Science and Biotechnology
• /
• v.15 no.1
• /
• pp.112-116
• /
• 2006

Levels of ethyl carbamate, by-product produced naturally during fermentation, in Korean alcoholic beverages were determined by Gas Chromatography/mass spectrometry/selected ion mode (GC/MS/SIM), and their daily intake by Korean adult group was estimated. In GC/MS/SIM analysis 0.8-10.1, 0.5-0.8, 0.4-0.9, 3.5-689.9, 8.4-30.3, 13.9-30.0, and 1.7-11.7 ppb of ethyl carbamate were detected in soju, beer, takju, fruit wine, cheongju, whiskey, and grape wine, respectively. Maximum daily exposure of ethyl carbamate through alcoholic beverage consumption was 7.41 ng/kg body weight/day for average Korean male, with one soju brand and two fruit wine brands showing high ethyl carbamate level.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.1
• /
• pp.9-15
• /
• 1999

Taurine contents in alcoholic and non alcoholic beverages, milk and milk products, sugars and condiments were determined for 83 food items commonly used by Koreans. Taurine concentrations of food samples were analyzed by using an automated amino acid analyzer(Biochrom 20, Pharmacia LKB) based on ion exchange chromatography. Taurine was not detected in most carbonated beverages, but found in a variety of fruit and vegetable beverages(canned) in the range of 0.13 ~1.43mg taurine/ 100g wt, and in instant coffee or tea beverages(canned) in the range of 0.10~0.41mg taurine/100g wt. The traditional Korean turbid rice wine(takju) sample contained the highest level of taurine (2.29mg/100g wt) among alcoholic beverages tested, which was followed by wine(0.59~0.88mg tau rine/100g wt) and beer(0.53~0.73mg taurine/100g wt). Ordinary milk samples contained 1.05~1.40 mg taurine/100g wt, and a variety of taurine supplemented infant formulas manufactured by Korean companies included 17.3~25.4mg taurine/100g wt. Taurine was not detected in most sugars and sweetners except a couple of chocolate samples(2.13~2.18mg taurine/100g wt). Exceptionally high level of taurine was found in a curry powder sample(16.9mg taurine/100g wt), while the rest of commonly used condiments contained less than 2.90mg taurine/100g wt.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.2
• /
• pp.183-188
• /
• 2002

The ohmic heating of foods for sterilization provides a shorter come-up time compared to conventional thermal processes. The electric fields as well as the heat generated by ohmic heating facilitate germicidal effects. In the present study, the effect of ohmic heating on the structure and permeability of the cell membrane of yeast cells, Saccharomyces cerevisae, isolated from Takju (a traditional Korean rice-beer), was investigated. The ohmic heating was found to translocate intracellular protein materials out of the cell wall, and the amount of exuded protein increased significantly as the electric field increased from 10 to 20 V/cm. As higher frequencies were applied, more materials were exuded. Compared to conventional heating, more amounts of proteins and nucleic acids were exuded when these cells were treated with ohmic heating. The molecular weights of the major exuded proteins ranged from 14 kDa to 18 kDa, as analyzed by Tricine-SDS PAGE. A TEM study also confirmed the leakage of cellular materials, thus indicating irreversible damage to the cell wall by ohmic heating. It was, therefore, concluded that the electric fields generated by ohmic heating induced electroporation, causing irreversible damage to the yeast cell wall and promoting the translocation of intracellular materials.

• Korean Journal of Food Science and Technology
• /
• v.27 no.2
• /
• pp.266-269
• /
• 1995

In order to measure alcohol contents with speed and accuracy, alcohol sensor was prepared. Alcohol sensor was made by connecting with oxygen electrode after immobilized alcohol oxidase on nylon net with glutaraldehyde. Alcohol was determined by changing the rate of dissolved oxygen consumption using D.O. analyzer. Alcohol contents in alcoholic beverages were determined under the optimum conditions. The results were 0.71% in low-alcohol beverage, $4{\sim}5%$ in beers, 10.06% in wine, 16.12% in chungju, 25.71% in soju, and 6.18% in takju, respectively. The values by alcohol sensor showed an excellent correlation(r=0.999) with GC method.

• The Korean Journal of Food And Nutrition
• /
• v.6 no.4
• /
• pp.287-293
• /
• 1993

This study was carried out to investigate the influences of cultural conditions of koji on the production of organic acid during rice-koji making by Aspergillus awamori var. kawachii which is now widely used as koji-mold in brewing Takju and Yakju in Korea. The optimum temperature for the germination of the conidia of the mold was 35'8, and the time required for germination at this temperature was 8 hours. Rapid germination occurred when the water content of steamed rice was above 40%, but germination retardation occurred markedly below 35%. The optimum cultural temperature for the production of organic acid was 32$^{\circ}C$, and the production of organic acid was markedly restricted at 36$^{\circ}C$ and 4$0^{\circ}C$. It was effective for the high production of both saccharogenic amylase and organic acid to shift the cultural temperature from initial 36$^{\circ}C$ to 32$^{\circ}C$ after 20~25 hours of cultivation. Initial water content suitable to the production of organic acid was 40% in steamed rice, but its production was markedly restricted below 30% of water content. When the quantity of conidial inoculation was too small, the production of organic acid was low in initial phase, but it was retrived at later period. Acid production was markedly restricted together with the increase in koji thickness.

• Food Quality and Culture
• /
• v.2 no.1
• /
• pp.43-47
• /
• 2008

This study examined the quality characteristics of Jeungpyun prepared with different additions of nano-filtered (NF) tofu whey concentrates. The initial pH values of the Jeungpyun batters ranged from 5.64 to 5.78, and decreased to 4.77-4.98 after 4 hours of fermentation at $35^{\circ}C$. The volume and specific volume values of the control Jeungpyun were lower than those of Jeungpyun samples prepared with 1%, 2%, and 3% NF powder. The color of the Jeungpyun became increasingly greenish-yellow as the NF powder level increased. Hardness and brittleness decreased with increasing NF powder content, while cohesiveness and springiness were not significantly different. Sensory evaluations revealed that as the level of NF powder increased, takju smell and sourness increased, but no significant differences were observed for sweetness and moistness between the control and NF powder groups. In terms of overall acceptability, the results revealed that Jeungpyun can be prepared with up to 1% NF powder in place of rice powder and be deemed as acceptable as a control Jeungpyun product.