• Food Science and Preservation
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• v.19 no.1
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• pp.159-166
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• 2012

To investigate the characteristics of $Gammakgeolli$ to which processed forms of persimmon were added, $Gokkam$, $Gammalaengi$, whole powder, peel powder, and paste were used as various processed forms. The moisture, total polyphenol, and soluble-solid contents of the persimmon used for making $Gammakgeolli$ showed a big difference according to the processed form of persimmon, and influenced the total polyphenol and alcohol contents of the $Gammakgeolli$. The pH and total acid of the $Gammakgeolli$, which were 3.7~4.1 and 0.20~0.29% (w/v), respectively, were similar to those of commercial $Makgeolli$. The amino acidity increased on the fifth day after fermentation from that on the third day, and showed relatively high levels in the whole power, peel power, and paste. The volatile-acid contents of the $Gammakgeolli$s were within the range of 80~100 ppm and showed the highest level in the persimmon-paste-treated sample. Among the major organic acids of $Gammakgeolli$ (oxalic, citric, tartaric, malic, succinic, lactic, and acetic acid), lactic acid had the highest concentration. The $Gammakgeolli$ to which hole power or paste was added showed a high level of yellowness and a good color in the sensatory evaluation. In the sensory evaluation (selection rate) of the taste and overall acceptability, the $Gammakgeolli$ treated with $Gammalaengi$ was the best.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.543-547
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• 2006

In order to improve wine quality, the selection of yeast strain and of additives in the manufacture of Bokbunja (Rubus coreanus Miq.) wine was investigated. The chemical composition of the edible portions of Bokbunja fruits was 86.5% moisture, 0.2% crude protein, 0.9% crude fat, 6.6% crude fiber, 0.5% ash and $10^{\circ}Brix$ sugar, and was 2.99% fructose, 2.53% glucose and 0.07% sucrose in fruit extract. The predominant organic acids in the fruit were citric acid (14.57 mg/mL) and malic acid (2.24 mg/mL) with smaller amounts of shikimic, pyroglutamic and oxalic acid. During fermentation, citric and malic acid levels decreased, while formic and acetic acid were released. Saccharomyces cerevisiae KCCM 12224 (Sc-24) was more favorable for alcoholic fermentation of Bokbunja and the addition of 200 ppm of potassium metabisulphite to must was more efficient than other $SO_2$ sources with a higher overall acceptability score. Sc-24 increased alcohol production from 9.8 to 14.8% in a sugar concentration dependent manner $(18-28^{\circ}Brix)$. The color value of early stage Bokbunja must was improved by supplementing with Japanese apricot extract, but this did not influence the color value of Bokbunja wine after primary fermentation. The astringent taste of Bokbunja wine was reduced by removing the seed from the fruit. Sugar solution (50%, w/v) was used instead of sugar power to prevent the possibility of undissolved sugar due to insufficient mixing. This substitution did not influence sensory evaluation.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1568-1579
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• 2001

This study is aimed at evaluating the effect of Aspergillus oryzae fermentation extract (AFE) on corn silage fermentation characteristics. Trial included two groups of treatments, with or without AFE inclusion in corn ensilage. Sixty corn silage containers, including two treatments with thirty replicates each, were processed in a laboratory scale mini-silo of 21 cm radius by 45 cm height. Three replicate containers were opened and sampled for analysis at 0, 0.5, 1, 2, 3, 4, 6, 10, 18 and 34 days after being ensiled. One silage container from each treatment was installed with a remote controlled electronic thermometer to record the temperature changes. Analysis included silage temperature, pH, fermentation acids, the water-soluble carbohydrates and chemical compositions and the silage protein fractions. Results showed that on the first day, the temperature of the ensiled corn was slightly higher than room temperature, but returned to room temperature on the second day. The pH and concentrations of WSC, ADF, lignin and acetic acid in the AFE treated silage were significantly lower than the control groups (p<0.05). The lactic acid and crude protein on the other hand were significantly higher in the AFE treated silage as compared to the control (p<0.05) at the end of the ensilage period. The DM content was significantly higher (p<0.05) whereas the butyric acid content of the AFE treated silage was significantly lower (p<0.05) than the control at the end of the 34 day ensilage period. Titratable acid and buffering capacity in the corn silage were not significantly different between treatment groups (p>0.05). Ammonia N concentration in the AFE treated silage showed a trend of decrease (p>0.05). NPN and the protein fraction A in both groups increased during the conservation period, but fraction A in the AFE treated corn silage was significantly higher than the control silage (p<0.05). During the conservation period, the AFE treated corn silage showed a trend toward a decrease in fractions $B_1$, $B_3$ and C (p<0.05). The protein fraction B2 showed a trend toward increase in the control group and an inconsistent trend in the AFE treated silage during the ensiling period. The AFE treated silage showed a better Flieg score over the control silage (97 vs. 75) as calculated from the concentrations of lactic acid, acetic acid and butyric acid.

• Journal of Korean Society on Water Environment
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• v.27 no.6
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• pp.926-931
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• 2011

Among various techniques for hydrogen production from organic wastewater, a dark fermentation is considered to be the most feasible process due to the rapid hydrogen production rate. However, the main drawback of it is the low hydrogen production yield due to intermediate products such as organic acids. To improve the hydrogen production yield, a co-culture system of dark and photo fermentation bacteria was applied to this research. The maximum specific growth rate of R. sphaeroides was determined to be $2.93h^{-1}$ when acetic acid was used as a carbon source. It was quite high compared to that of using a mixture of volatile fatty acids (VFAs). Acetic acid was the most attractive to the cell growth of R. sphaeroides, however, not less efficient in the hydrogen production. In the co-culture system with glucose, hydrogen could be steadily produced without any lag-phase. There were distinguishable inflection points in the accumulation of hydrogen production graph that resulted from the dynamic production of VFAs or consumption of it by the interaction between the dark and photo fermentation bacteria. Lastly, the hydrogen production rate of a repeated fed-batch run was $15.9mL-H_2/L/h$, which was achievable in the sustainable hydrogen production.

• Food Science and Preservation
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• v.31 no.4
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• pp.673-681
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• 2024

This study was conducted to develop kombucha with better functionality. The developed kombucha (CK) was prepared using the sugar extracts from fruits of Cudrania tricuspidata (Carrière) Bureau ex Lavallée instead of the sugar, which is used as a substrate for SCOBY in conventional kombucha (K). During fermentation, the soluble solids content significantly decreased in CK compared to K, and the pH change decreased rapidly in CK compared to K. On the 14^th day of fermentation, the weight of the SCOBY in CK was higher than that in K. Immediately after preparation, K contained only sucrose, but CK contained sucrose, glucose, and fructose. SCOBY appears to use glucose and fructose preferentially during fermentation. K contained acetic acid and citric acid right after preparation. However, as fermentation progressed, the composition changed to acetic acid, citric acid, and lactic acid. At the same time, CK initially consisted of citric acid, lactic acid, and acetic acid. However, acetic acid and citric acid increased but lactic acid decreased significantly on the 14^th day of fermentation. In the cytotoxicity studies, the CK showed a proliferation-promoting effect on normal lung cells (MRC-5) and strong cytotoxicity against human lung cancer cells (A549). These results suggest that the kombucha made from sugar extracts of C. tricuspidata fruits can be used as a more functional beverage than regular kombucha.

• Journal of the Korean Society of Food Culture
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• v.16 no.5
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• pp.431-441
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• 2001

To develop the low-temperature and long-term fermented kimchi, kimchi was prepared according to the recipe of a specific ratio of major and minor ingredients and adjusted its salinity to 3.7%. Prepared kimchi fermented at $15{\pm}1^{\circ}C$ for 24 hours and transferred and fermented in a refrigerator only used to make low-temperature and long-term fermented kimchi at $-1{\pm}1^{\circ}C$ for 30 weeks. During 30 weeks of fermentation the changes in physicochemical and microbiological properties of low-temperature and long-term fermented kimchi were studied. The initial pH of 6.47 decrease gradually and dropped to pH 4.0 after 14 weeks of fermentation, and then it maintained at same level. Acidity increased to 0.49% on 2 weeks of fermentation and kept at 0.47 $\sim$0.50% during 2 to 30 weeks fermentation. Salinity was slightly increased at early stage and started to decrease on 4 weeks of fermentation, and then it did not change. The change of reducing sugar content was closely related to the trend of pH change with a very high correlation coefficient(r =0.912). Lactic acid, citric acid, malic acid, succinic acid and acetic acid were major organic acids contained in low-temperature and long-term fermented kimchi. Vitamin C content decreased at initial stage of fermentation and then slightly increased up to the maximum of 22.3 mg% on 8weeks of fermentation. In color measurement, L value continued to increase during the fermentation and reached at the highest of 55.45 on 22 weeks of fermentation, and a and b values of 3.62 and 4.54 also increased to 31.26 and 37.32 on 30 weeks of fermentation, respectively. Total microbial count increased slowly from beginning and was the highest on 4 weeks of fermentation, and then began to decrease slowly. Count of Lactobacillus spp. was highest after 6weeks, but count of Lactobacillus spp. was highest on 2 weeks of fermentation, and then both showed a slow decrease. Yeast count wasn't increased until 4 weeks of fermentation and then increased rapidly to get the highest on 10 weeks of fermentation.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.503-512
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• 2020

To enhance the usability of puffed rice, we evaluated the quality characteristics and antioxidant activity of vinegar made with puffed rice and lemon balm. First, puffed rice containing lemon balm extracts was fermented for alcohol production. The alcoholic fermented liquid was adjusted to an alcohol content of 6% and an initial acidity of 2% for vinegar fermentation. The pH and alcohol content of the lemon balm vinegar decreased overall as fermentation progressed. The total acidity was 5.20±0.01% (2.0% lemon balm) to 5.80±0.01% (0.0% lemon balm) on the 15th day of fermentation, and the total acidity was slightly lower as the amount of added lemon balm was increased. Citric, succinic, and acetic organic acids were detected in the vinegar and the acetic acid content was highest at 4.81% to 5.37% on the 15th day of fermentation. We found that the total polyphenol and total flavonoid content of the lemon balm vinegar increased as we added lemon balm, and the content on the 15th day of fermentation was 179.4±4.5 (0.0% lemon balm) - 340.8±2.6 mg/kg (2.0% lemon balm) and 1.5±0.3 (0.0% lemon balm) - 31.7±0.3 mg/kg (2.0% lemon balm), respectively. The higher the amount of lemon balm added, the higher the DPPH radical scavenging activity, the FRAP (reducing power), and the ABTS radical scavenging activity. Moreover, those activities after 2.0% lemon balm treatment were 82.99±0.61%, 1.08±0.01 abs., and 87.67±0.68%, respectively, on the 15th day of fermentation. These results suggest that vinegar with added lemon balm may be used as an antioxidant agent.

• Food Science and Preservation
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• v.16 no.6
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• pp.804-809
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• 2009

Recently, many Koreans have started to consume aged kimchi fermented long-term at low temperatures. In the present study, the effect of low temperature ($5^{\circ}C$) on pH, titratable acidity (TA), organic acid level, viable microbial cell count, amino acid concentration, and polygalacturonase activity (PG) during long-term fermentation (46 weeks) of kimchi, were evaluated. After 10 weeks of fermentation, kimchi had a pH of 4.1 and a TA of 1.0%, respectively after 46 weeks fermentation, these values were 3.9 and 1.3%, respectively. Lactic acid, the ratio of lactic acid to acetic acid, and the ratio of Lactobacillus species/Leuconostoc species in kimchi increased as fermentation progressed from 10 weeks to 46 weeks. However, total viable cell counts of aerobic bacteria, yeasts, Lactobacillus species, and Leuconostoc species, free amino acid levels, and PG decreased as the fermentation period was extended from 10 weeks to 46 weeks.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.569-573
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• 2009

The biochemical and microbiological changes of the hard clam shikhae were studied during fermentation at $4-18^{\circ}C$ for 45 days. For preparation of the shikhae, the shucked hard clams were blanched into 2% saline solution and were soaked in seasoning solution before mixing with salt, cooked grain and spices. During fermentation, the initial pH steadily decreased from 5.0 to 4.6, but $NH_2-N$ and VBN concentrations increased to 127 mg/100 g and 27.0 mg/100 g, respectively. Alanine, taurine, glutamic acid, and aspartic acid concentrations increased, but arginine concentration decreased by fermentation. The major organic acids of the fermented shikhae were lactic acid, succinic acid and acetic acid. The major free sugar were maltose, glucose and fructose. The concentration of total viable cell ($2.1\times10^5$ CFU/g) and proteolytic bacteria ($1.2\times10^5$ CFU/g) increased to $4.4\times10^8$ CFU/g and $9.8\times10^7$ CFU/g, respectively until day 15 and then slightly decreased. The concentration of yeast ($2.4\times10^3$ CFU/g) increased to $1.6\times10^7$ CFU/g until day 25, but lactic acid bacteria ($5.0\times10^8$ CFU/g) increased to $5.0\times10^8$ CFU/g until day 9. Vibrio species was not detected on the TCBS agar during fermentation.

• Preventive Nutrition and Food Science
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• v.16 no.1
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• pp.74-82
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• 2011

The fermentation and quality characteristics of kimchi, made by adding different types of red pepper (semi-dried red pepper, fresh red pepper, dried red pepper) according to drying conditions, were examined for 15 days at $10^{\circ}C$ fermentation. The initial pH was approximately 5.65~5.72 in all groups, and the pH decreased with increasing fermentation time. The color value of a/b showed the highest in kimchi that made with semi-dried red pepper (SDRP-K). The color value of A remained at the initial level for 9 days, regardless of treatments. The color value had a tendency to decrease after 9 days. The lactic acid bacteria increased rapidly during 6 days of storage, but showed no difference among groups. The initial contents of malic acid and succinic acid were in 3.23~4.52 and 6.12~7.97 mg/mL and decreased during fermentation in all groups. The lactic acid and acetic acid were not contained in the beginning, but increased with increasing fermentation periods. The vitamin C content of SDRP-K was 5.20 mg/g, which was significantly higher compared with kimchi that made with dried red pepper (DRP-K), but which did not show any significant difference to kimchi that made with fresh red pepper (FRP-K). As a result of antioxidant activity in optimally ripened kimchi, both $DPPH^+$ and $ABTS^+$ scavenging activities were higher in SDRP-K than any other groups. As a result of the sensory evaluation, overall acceptability was highest in SDRP-K.