• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.5
• /
• pp.788-793
• /
• 1997

Addition of sugar, enzymatic hydrolysis and salt concentration were evaluated for their effects on the changes in some characteristics of Kimchi juice during fermentation. The Kimchi juice was prepared by brining and grinding of outer layer leaves of chinese cabbage, one of the wastes products of Kimchi processing, followed by fermentation proceeded significantly faster. Addition of sucrose or glucose at the ange of 0.5~2.0 % also improved the fermentation but the concentration effect was little. Enzymatic hydrolysis on the brined cabbage prior to fermentation with a commercial polysaccharides hydrolases also increased the fermentation. However the solid concentration in Kimchi juice was rather decreased by higher concentration of NaCl and enzymatic hydrolysis. The reducing sugar content showed a rapid decrease from 24 hours of fermentation and the effect of enzymatic hydrolysis was little.

• Microbiology and Biotechnology Letters
• /
• v.22 no.5
• /
• pp.531-537
• /
• 1994

This study was undertaken with objective of optimizing the conditions of fermentation in an aqueous two-phase system which is composed of polyethylene glycol (PEG) 20000 and crude dextran (Dx). The data were obtained and analyzed using the Box-Wilson's experimental design protocol and the response surface methodology. To reach this end a multilinear polynomial regres- sion model was developed, which can be utilized for the purpose of optimizing the extractive fermentation. Optimum conditions for batch fermentation with aqueous two phase system were found to be at 4.2~5.4% PEG/3.2~4.2% Dx range. The composition of the center was 4.8% PEG/ 3.6% Dx. Optimum operating conditions for initial sugar concentration and fermentation time were approximately 160 g/l, and 21~22 hr, respectively. Fermentation in the aqueous two phase system composed of 5% PEG/4% Dx showed increase of 23% in ethanol concentration, of 9.5% in ethanol yield, and of 19% in ethanol productivity as compared to the case of fermentation of neat Jerusalem artichoke juice.

• Food Science and Preservation
• /
• v.7 no.1
• /
• pp.89-93
• /
• 2000

The study was conducted to investigate the characteristics of peach vinegar by parallel-complex fermentations. The vinegars prepared by using Changbnag-Chosang and Yumung peach cultivars added with 7, 10, and 13% sugaring concentrations were examined. The rate of increase in alcohol degree and titratable acidity, and that of decrease in soluble solids showed higher at Yumyung peach than at Changbang-chosang. Alcohol and acetic acid fermentation by paralle-complex fermentation were performed better in Yumyung peach than Changbang -chosang. but the fermentation of Yumyung showed active alcohol fermentation in the early stage, and active acetic acetic acid fermentation in the late stage. Quality of the vinegar prepared with Yumyung peach was better than that of Changbang-chosang, which were evaluated by acetic acid contents , peach taste and odor in the vinegar, and overall taste. The fermentation was accelerated with an increase in sugaring , concentrating but overall taste was best in 10 % sugaring.

• Journal of the East Asian Society of Dietary Life
• /
• v.5 no.3
• /
• pp.287-298
• /
• 1995

This study was undertaken to examine the effect of salting in 10% salt solution added 2% calcium chloride on the kimchi fermentation. The addition of calcium chloride extended edible periods of the Kimchi to 4~5 days and increased relatively the hardness of Chinese Cabbage. In the addition of calcium chloride, the activities of amylase and $\beta$ -galactosidase were not high during all periods fermentation. Polygalacturonase and protease activities were low 2~21%, 2~26% all periods fermentation, respectively. There were significant correlations between the delay of ripeness and decreasing enzyme activation. The amount of free amino acid by the treatment with calcium chloride was decreased of 10~16% at the late of fermentation than that of control. the treatment with calcium chloride of the Kimchi was increased hardness, but decreased cohesiveness and gumminess was during all periods fermentation. the adhesiveness was increased at the early of fermentation but decreased at the late of fermentation.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.10
• /
• pp.1703-1708
• /
• 2004

This study was carried out to investigate the characteristic quality of jeungpyun added Paecilomyces japonica with different fermentation time. The volume of jeungpyun added Paecilomyces japonica was more increased after fermentation. The volume was decreased when the fermentation was progressed. The pH was 5.1 before fermentation and the pH decreased when the fermentation was progressed. Moisture content was more increased as the time of fermentation became longer. Hunter color test, L value and b value appeared the highest after 1st fermentation, and it appeared lesser when the time of fermentation became longer. In measurement of texture, hardness showed the highest value when 90 minutes passed after the 2nd fermentation. Gumminess and brittleness were tend to increase when it have longer fermentation time. In scanning electron microscopic observation, organization of sponges was tend to break down as the fermentation time was longer. Sensory properties showed that color intensity was more strong when second fermentation was progressed, and hardness, toughness, sourness were high when the fermentation time was longer. In conclusion overall acceptability of jeungpyun, 3$0^{\circ}C$, 3 hours after 1st fermentation and 2nd fermentation for 30 minutes, 35$^{\circ}C$ showed the most preference.

• The Korean Journal of Mycology
• /
• v.31 no.1
• /
• pp.28-33
• /
• 2003

To establish the optimal fermentation periods in the manufacture of mushroom fermentation foods using sugar, changes of quality characteristics of the mushrooms fermentation broth were investigated with changes of enzyme activity and physiological functionality during fermentation. Viscosity, L value (lightness), a value (redness) and b value (yellowness) were significantly decreased after 3 months of fermentation and after that, increased. In sensory evaluation test, unique flavors and tastes of mushrooms in the fermented broth were decreased during fermentation, whereas the other tastes and flavors were gradually increased. Overall acceptability was the highest in the 3 months of fermentation broth. ${\alpha}-Amylase$ activities of the fermented broth were significantly increased to 1 month of fermentation, however invertase and cellulose activities were low or not detected in the fermented broth. Antioxidant activities were the highest in 4 months of fermentation and after that, decreased. Tyrosinase inhibitory activities were high in all samples and they were not changed during fermentation. SOD-like activity was high in the fermentation broth of Flammulina velutipes and it was also not changed during fermentation. In conclusion, optimal fermentation periods in the manufacture of mushroom fermentation foods using sugar was 3 or 4 months.

• Korean Journal of Food Science and Technology
• /
• v.35 no.2
• /
• pp.272-279
• /
• 2003

To determine optimal fermentation period of wild vegetables mixed with black sugar without microorganisms during plant extract fermentation food processing, changes in chemical components, quality characteristics of the fermented broth, and physiological functionality during fermentation period were investigated. pH and $^{\circ}Bx$ of fermented broths decreased gradually during fermentation period. Except persimmon leaf, viscosity of fermented broths of wild vegetables decreased after 3 months fermentation period. Amylase activity increased to $167{\sim}800%$ of its initial level after 6 months fermentation period, and invertase activity decreased by $60{\sim}170$ units after 1 month fermentation. No significant level of cellulase activity was observed. In the sensory evaluation test, inherent flavors and tastes of the wild vegetable decreased during the fermentation period, while those of others gradually increased. Overall acceptability was the highest after 3 months fermentation. Content of total phenolic compounds and electron-donating ability were highest after 3 to 4 months fermentation period, and decreased thereafter. Except Mugwort, tyrosinase inhibitory activity was found in all fermented broths. SOD-like activities were $23.0{\sim}25.1$ and $27.0{\sim}29.2%$ in fermentation broths of acacia flower and persimmon leaf, respectively, and were maintained throughout the fermentation period. Based on these results, fermentation period of 3 to 4 months was determined to be appropriate for plant extract fermentation food processing.

• Food Science and Preservation
• /
• v.6 no.2
• /
• pp.228-232
• /
• 1999

Total acidities were incereased gradually during fermentation. Total acidities of vinegars which fermented from sweet and astringent persimmon were 5.95 and 5.81% at 8th day of acetic acid fermentation, respectively. Hunter's color values were not significant difference during alcohol fermentation and acetic acid fermentation. Browning incereased continuously during alcohol fermentation whereas browning and turbidity decreased continuously during acetic acid fermentation. The browning and turbidity of vinegar which fermented from sweet persimmon was higher than those of vinegar which fermented from astringent persimmon. The contents of total tannin were 2.40 and 6.44mg/ml at the initial fermentation of sweet and astringent persimmon respectively. But in contents decreased continuously during fermentation. Reducing and total sugar contents decreased continuously during fermentation. At 5th day of acetic acid fermentation, contents of reducing and total sugar were 5.0 and 8.5mg/ml in sweet persimmon and 2.8 and 2.9mg/ml in astringent persimmon respectively.

• Journal of Microbiology and Biotechnology
• /
• v.4 no.3
• /
• pp.222-229
• /
• 1994

In order to develop a method of economical production and to reduce energy-consumption in fuel alcohol production, we investigated the fermentation characters of two newly selected thermotolerant yeasts. The RA-74-2 showed stable and superior fermentability between 30 and $40^{\circ}C$ in 20% glucose media in comparison to the industrial strains. The optimum concentration of glucose for economical fermentation at $40^{\circ}C$ was 15-18%, and organic nitrogen was necessary for a satisfactory fermentation. The optimum pH was 4.0 and aeration was adversed for high temperature fermentation. Agitation was an important factor at $40^{\circ}C$ and the addition of magnesium ion 0.2% was required in this experiment. When the inoculum was increased, ethanol productivity as well as the speed of fermentation increased. On the other hand RA-912, which can grow at $48^{\circ}C$, showed similar fermentability between 30-$45^{\circ}C$ in 20% glucose media As the concentration of substrate decreased, fermentation ratio increased at $45^{\circ}C$ (45%, 65%, 95% fermentation ratio in 20%, 15%, 10% glucose media, respectively). Also, requirement of organic nitrogen and magnesium ion in RA-912 was similar in RA-74-2. The optimum pH for fermentation was 5.0, and the effects of agitation were enhanced at $37^{\circ}C$ than at $45^{\circ}C$. As the inoculum was increased, fermentation speed became more enhanced but the ethanol productivity was less affected. RA-912 showed fermentability with various substrates. Among the substrates used, inulin was the most promising substrate for the high-temperature fermentation. When 14.5% inulin was used as the substrate, 93% and 55% fermentation ratios were shown at $37^{\circ}C$ and $45^{\circ}C$, respectively.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.8
• /
• pp.1195-1206
• /
• 2020

Beringraja pulchra, Cham-hong-eo in Korean, is a mottled skate which is belonging to the cartilaginous fish. Although this species is economically valuable in South Korea as an alkaline-fermented food, there are few microbial studies on such fermentation. Here, we analyzed microbial changes and pH before, during, and after fermentation and examined the effect of inoculation by a skin microbiota mixture on the skate fermentation (control vs. treatment). To analyze microbial community, the V4 regions of bacterial 16S rRNA genes from the skates were amplified, sequenced and analyzed. During the skate fermentation, pH and total number of marine bacteria increased in both groups, while microbial diversity decreased after fermentation. Pseudomonas, which was predominant in the initial skate, declined by fermentation (Day 0: 11.39 ± 5.52%; Day 20: 0.61 ± 0.9%), while the abundance of Pseudoalteromonas increased dramatically (Day 0: 1.42 ± 0.41%; Day 20: 64.92 ± 24.15%). From our co-occurrence analysis, the Pseudoalteromonas was positively correlated with Aerococcaceae (r = 0.638) and Moraxella (r = 0.474), which also increased with fermentation, and negatively correlated with Pseudomonas (r = -0.847) during fermentation. There are no critically significant differences between control and treatment. These results revealed that the alkaline fermentation of skates dramatically changed the microbiota, but the initial inoculation by a skin microbiota mixture didn't show critical changes in the final microbial community. Our results extended understanding of microbial interactions and provided the new insights of microbial changes during alkaline fermentation.