• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.8
• /
• pp.466-473
• /
• 2018

The purpose of this study is to develop a distilled soju with high quality and stable brewing technology by analyzing the changes of general components and volatile components in the production of distilled soju by the use of fermentation agent such as koji and nuruk. White rice flour was used as a main raw material. White koji, yellow koji, traditional nuruk, and improved nuruk were used as a fermentation agent respectively. Also, yellow koji, traditional nuruk, and improved nuruk were added at a certain ratio to prepare white koji. The distillate was prepared by vacuum distillation and the quality characteristics were compared and analyzed. When the fermentation agent was used alone, the alcohol content was higher in the order of white koji, improved nuruk, yellow koji, and traditional nuruk. The initial acidity was higher than that of other fermentation agents and the highest alcohol content was found to be helpful for stable brewing. The highest content of higher alcohol was found in the yellow koji mash, and ethyl acetate was the highest in the traditional nuruk. When the fermentation agents were mixed, there was no difference in the alcohol content between $1^{st}$ fermentation mash and $2^{nd}$ fermentation mash. On the other hand, the content of higher alcohol was increased with the increase of the input ratio of yellow koji, and it decreased with the increase of the ratio of traditional and improved nuruk. It is expected that it will be possible to manufacture various distilled soju with different flavor and aroma if the yellow koji and the traditional nuruk are appropriately used based on the white koji having excellent fermentation characteristics and it will be very helpful for improving the stability and quality of brewing.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.7
• /
• pp.848-856
• /
• 2017

This study aimed to investigate the effect of rice nuruk prepared from rice with different degrees of milling (0, 10, 30, 50, and 70%) on physicochemical qualities of yakju. The results indicated significant differences in the qualities of yakju prepared using rice nuruk from rice with different degrees of milling. Specially, pH, amino acidity, brownness, b value, and color difference were significantly reduced as the degrees of milling increased, whereas contents of alcohol and volatile acid, reducing sugar, and L value were increased. Malic acid, succinic acid, and lactic acid were the main organic acids in yakju, and there were significant differences among the treatments in malic acid, lactic acid. However, there was no tendency according to different degrees of milling. In addition, contents of total free amino acids and nitrogen compounds showed no tendency according to degrees of milling, whereas the content of aspartic acid showed a tendency to decrease significantly. The content of 2-phenyl alcohol in the volatile flavor components showed a tendency to increase significantly with higher degree of milling of rice nuruk, whereas contents of n-propanol and iso-amyl alcohol tended to decrease significantly.

• Korean Journal of Food Science and Technology
• /
• v.28 no.6
• /
• pp.1171-1176
• /
• 1996

The changes in volatiles of the model system were analyzed by GC and GC-MS before and after retorting. The GC data were analyzed statistically by applying the analysis of variance, and 42 peaks were selected at 5% significance level. Multivariate statistical analysis was performed with these 42 peaks as independent variables. Through the stepwise discriminant analysis, 8 peaks, which corresponded to the compounds such as 2-heptanone, cis-3-hexenal, 2-pentyl-furan, 1-methyl-trans-1,2-cyclohexanediol, 2-hexanone, 3-octanone, trans, trans-nona-2,4-dienal and 1-octen-3-ol, were obtained in sequence to distinguish the samples with and without retorting. The principal component analysis of a set of 8 independent variables resulted in 3 principal components which accounted for 96.1% of the variance, while the first principal component (PC 1) explained 76.5% of the total variance. In addition, through the factor analysis of the principal components, the peaks 11, 20 and 21 could be grouped togather in accordance with the direction and the size while the peaks 9, 33 and 39 constituted the second group in the direction.

• Food Science and Preservation
• /
• v.15 no.2
• /
• pp.243-252
• /
• 2008

We investigated the physicochemical properties of Ganjang added to a medicinal herb extract (functional Ganjang). 1be proximate compositions of conventional Ganjang (control) and functional Ganjang (supplemented with 3% or 5% of an hem extract) were not significantly different Analysis of total and free amino acids indicated 17 different amino acids in both types of Ganjang. Glutamic acid was the most common, followed by valine, leucine, isoleucine, lysine, methionine, phenylalanine, and threonine. Sensory tests of conventional and functional Ganjang found no significant differences. An analysis of flavoring components indicated that flavor-active compounds (paeonol, senkyunolide A, and cnidilide) were present in both forms of Ganjang. Our results suggest that the extract could be used to manufacture fermented soybean products.

• Korean Journal of Food Science and Technology
• /
• v.49 no.4
• /
• pp.369-376
• /
• 2017

Maturation of distilled spirit can generate diverse flavors and tastes. Rice Soju was matured in oak casks (MSO) and stainless steel containers (MSS) for one year at ambient temperature. Ipguk (Aspergillus luchuensis) and Saccharomyces cerevisiae Y88-4 were used, and reduced pressure ($110{\pm}20Torr$) distillation was applied to brew Soju. Acidity and conductivity were increased in both MSO and MSS. MSO reduced alcohol content (from 43 to 40%) and volume (from 18,000 to 12,730 mL), and significantly altered yellowness (from 0.2 to 30.2). Furthermore, MSO increased the isoamyl alcohol (from 276.7 to $339.2{\mu}g/mL$) and isobutyl alcohol (from 122.3 to $144.2{\mu}g/mL$) content. Gas chromatography-mass spectrometry was used to detect volatile compounds in Soju, which included 20 esters, 7 alcohols, 2 acids, and 5 miscellaneous compounds. Oak lactone was detected only in MSO and was considered as a specific flavor component associated with oak maturation. Thus, maturation materials contribute to the physicochemical property of distilled spirits.

• Korean Journal of Food Science and Technology
• /
• v.32 no.6
• /
• pp.1258-1265
• /
• 2000

In oder to acquire microbial agents that can be utilized for control of aflatoxin produced by Aspergillus. flavus and Asp. parasiticus, antifungal bacteria were isolated. Antifungal bacteria was identified as Bacillus spp. based on morphology and physico-biochemical characteristics. Amount of aflatoxin $B_1$ from Doenjang(soybean paste) prepared with Asp. flavus, Asp. parasiticus, antifungal bacteria(Bacillus sp.), or mixture of Asp. flavus and Asp. parasiticus was 27.2 ppb, 30.3 ppb, 3.4 ppb, and 3.7 ppb, respectively. Aflatoxin $B_1$ was not detected from Doenjang(control) and Doenjang prepared with antifungal bacteria. Content and compositions of free sugars, fatty acid, organic acid and free amino acid in Doenjang prepared with Asp. flavus and Asp. parasiticus, antifungal bacteria and mixture of Asp. flavus and Asp. parasiticus were not significantly different. For volatile flavor compounds of Doenjang prepared with antifungal bacteria, 2-pentyl furan and butanoic acid were disappeared or reduced, while octadecene compounds were produced. However, those of Doenjang prepared with Asp. flavus or Asp. parasiticus and Doenjang(control) were not significantly different. These results suggested that the antifungal bacteria(Bacillus sp.) inhibited production of aflatoxin and that antifungal bacteria did not effect the quality of Doenjang.

• The Korean Journal of Food And Nutrition
• /
• v.30 no.5
• /
• pp.889-899
• /
• 2017

To investigate the quality characteristics of domestic $ros{\acute{e}}$ wines marketed in Korea, 11 kinds of wines were purchased at the Korea Wine Festival in 2016. The color, physiological activity, aroma component and sensory evaluations were conducted. The hue value of $ros{\acute{e}}$ wines ranged from 0.592 to 1.990, with the Ro7 of Delaware having the highest value. The brightness of $ros{\acute{e}}$ wines ranged from 42.96 to 94.99, the redness from 3.20 to 59.37, and the yellowness from 8.43 to 24.83. Of the 11 $ros{\acute{e}}$ wines evaluated, 1 was a dry wine and 10 were sweet wines. The average sugar content of the sweet wines was 73.89 mg/mL. Among the organic acid contents, malic acid ranged from 0.214 to 2.903 mg/mL, and lactic acid content ranged from 0 to 3.423 mg/mL. Malolactic fermentation differed, depending on the source. The total polyphenol content of $ros{\acute{e}}$ wines ranged from 50.55 to 99.55 mg%, the anthocyanin content was 2.12 to 213.30 mg/L, and the DPPH radical scavenging activity of $ros{\acute{e}}$ wines was between 73.75 to 90.41%. A total of 41 volatile components were detected, including 7 alcohols, 22 esters, 4 terpenes, 3 acids and 5 other compounds. Of these, 9 compounds had odor activity value(OAV) greater than 1; these were identified as 1-propanol (alcohol, pungent), 3-methyl-1-butanol (harsh, nail polish), ethyl butanoate (strawberry, lactic), isopentyl acetate (fresh, banana), ethyl hexanoate (green apple, fruity), ethyl octanoate (pineapple, pear, floral), ethyl decanoate (fruity, fatty, pleasant), linalool (flower, lavender) and limonene (lemone, orange). As a result of the sensory evaluation, the Ro5 wine made from Campbell Early grape, and having a good color, flavor and taste, was the most preferred.

• Food Science and Preservation
• /
• v.24 no.2
• /
• pp.187-195
• /
• 2017

This study evaluated quality characteristics of soybean fermented by selected lactic acid bacteria, which were the enzyme strains with high antimicrobial activities isolated from traditionally prepared soybean paste. We determined total aerobic and lactic acid bacteria counts, protease and amylase activities, reducing sugar and amino-type nitrogen contents, and the amounts of amino acids, organic acids, and aroma-compounds. The total aerobic bacteria counts in soybean fermented with strain I13 ($7.75{\times}10^9CFU/mL$) were the highest among all the strains analyzed. Lactic acid bacteria numbers were $2.85{\times}10^9$ to $4.35{\times}10^9CFU/mL$ in soybean fermented with isolates. Amylase and protease activities of the JSB22 sample were the highest among all sample. Reducing sugar and amino-type nitrogen contents of soybean fermented with JSB22 (1.23%, 94.52 mg%) were highest. Total amino acid content of the samples was 15.88-17.62%, and glutamic acid, aspartic acid, leucine, lysine, and arginine were the major amino acids. Lactic acid (0.82-3.65 g/100 g), oxalic acid (22.74-63.57 mg/100 g), and fumaric acid (2.88-6.33 mg/100 g) were predominant organic acids. A total of 39 volatile aroma-compounds were identified, including 2 esters, 5 ketones, 7 alcohols, 14 hydrocarbons, 2 heterocyclic compounds, 4 acids, and 5 miscellaneous compounds. These results represent useful information for the development of a starter (single or complex) and will be used for production of functional fermented soybean foods.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.6
• /
• pp.800-806
• /
• 2007

This study investigated the quality characteristics of kiwi wine during low temperature aging on several alcohol fermentation strains. Alcohol content increased sharply from 2 days of fermentation, and then maintained steadily after 8 days of fermentation. In the alcohol content of kiwi wine on several alcohol fermentation strains such as Sacch. cerevisiae GRJ, Sacch. kluyveri DJ97 and Sacch. cerevisiae Wine 3 showed a high value of more than 13%, 12.7% for Zigosacch. cerevisiae JK99 and 12.3% for Sacch. cerevisiae OMK, respectively. Sugar content decreased steadily during fermentation and then showed approximately $10^{\circ}$Brix on 8 days of fermentation. Total acidity ranged $1.03{\sim}1.04%$ in total samples, increased slowly during fermentation and then maintained steadily during aging. During the fermentation, L value in Hunter's color value continued to increase, a value decreased steadily and b value showed high yellow to approximately 20.0. For aging duration, L and b values decreased while a value increased. Glucose and maltose were detected as free sugars of kiwi wine. In volatile flavor compounds, alcohols were identified differently on alcohol fermentation strains, but the others showed similar tendency. In conclusion, quality characteristics of kiwi wine on several alcohol fermentation strains showed similarly; however, Sacch. cerevisiae Wine 3 was overall the most suitable.

• Korean Journal of Food Science and Technology
• /
• v.49 no.4
• /
• pp.383-389
• /
• 2017

This study aimed to select a yeast strain for optimizing the quality of distilled spirits. The brewing and distilling properties of 4 KFRI (Korea Food Research Institute) yeasts (Y88-4, Y98-4, Y172-6, Y192-4) and 2 industry yeasts (C1, C2) were compared. For investigating the possibility of using these strains on an industrial scale, diverse analytical methods were applied to assess parameters associated with distilled spirit quality such as alcohol content, pH, total acidity, and soluble solid content. After 11 days of fermentation, the alcohol strength obtained using six yeast strains reached 13.9-16.4% (v/v), while pH was 3.9-4.0, and total acid was 0.40-0.52%. To compare GC-MSD Volatile flavor components, all the distilled spirit samples were diluted to 20% (v/v) alcohol strength. Seven fusel alcohols, 26 esters, 2 acids, and 3 miscellaneous compounds were detected in the distilled spirits. Y88-4 had the most abundant volatile flavor component and scored the highest overall preference in sensory evaluation. After analyzing the various properties of yeasts, strain Y88-4 was finally selected as the best strain for producing distilled spirits.