• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.179-184
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• 2012

The objectives of this study were to manufacture the red ginseng vinegar based on rice wine and red ginseng concentrate (RGC) using $Acetobacter$ $aceti$ and to evaluate its quality with remaining crude saponin contents and sensory score. The maximum prosapogenin (ginsenoside-Rh1, Rh2, Rg2, and Rg3) content in RGC regarding ginseng was obtained from such processes as steaming, drying, and extraction. When RGC was added into a rice wine in the range of 0-1% before acetic fermentation, pH decreased slowly during 20 days depending on RGC contents, but total acidity was not dependent on RGC contents. Compared to the crude saponin content (71.75 mg/g) of ginseng vinegar added RGC after acetic fermentation, the fermentation with RGC produced a lower crude saponin content (16.95 mg/g) in red ginseng vinegar. Sensory scores such as odor, taste, and overall preference, however, vinegar fermented with RGC were higher than those of vinegar added RGC after acetic fermentation.

• KSBB Journal
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• v.5 no.2
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• pp.167-173
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• 1990

This study is to investigate for obtaining the operating conditions of continuous vinegar production using fluidized bed reactor by Acetobacter aceti cell immobilized in Ca-alginate gel. The optimum conditions obtaining by batch fermentation using fluidized bed reactor were as follows; The fermentation temperature and aeration rate were 3$0^{\circ}C$ and 1.0VVM and the initial concentration of ethanol and acetic acid in medium were 33g/l and 27g/l respectively. The amount of bead used was 25%(w/v). The overall acetic acid productivities of batch fermentations by free cell and immobilized cell were 0.31g/l-hr and 0.48g/l-hr, respectively, at the final acetic acid concentration of 50g/l. In the continuous vinegar production using fluidized bed reactor by immobilized cell under optimum conditions, it was possible to produce 23g/l acetic acid continuously up to 90 days with maximum acetic acid productivity of 2.76g/l-hr at dilution rate 0.12hr-1.

• Korean journal of food and cookery science
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• v.9 no.4
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• pp.257-260
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• 1993

For the purpose of supplying the information to improve the acceptability of soy paste as the condi-ment, we investigated the changes of free sugar, volatile and nonvolatile organic acids during improved soypaste fermentation. The results were as follows; Free sugars were increased in order of glc> xyl>ara>gal. Acetic, formic, butyric, and propionic acid in volatile organic acids were detected. And total contents were increased until 60 day. In 180 day, contents of volatile organic acids were high in order of acetic>propionic> butyric> formic. The contents of succinic and glutaric acid in nonvolatile organic acids were predominent and increased in order of succinic>glutaric>lactic. Tartaric>citric>malic acid were produced in the next order.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.937-945
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• 2014

Green and black tea by-products, obtained from ready-made tea industry, were ensiled at $10^{\circ}C$, $20^{\circ}C$, and $30^{\circ}C$. Green tea by-product silage (GTS) and black tea by-product silage (BTS) were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG) as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at $10^{\circ}C$. The GTS stored at $20^{\circ}C$ and $30^{\circ}C$ showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on $NH_3$-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and $NH_3$-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and $NH_3$-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin's activity in the rumen.

• Food Science and Preservation
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• v.6 no.2
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• pp.179-183
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• 1999

This study were comparison the quality characteristics of winter Chinese cabbage and investigation the physicochemical properties during Kimchi fermentation. External characteristics of three cultivars winter Chinese cabbage were compared, total weight of "Manpung" cultivar showed the heaviest in Chinese cabbages, but edible portion weight of "Seolwang" cultivar showed the heaviest in Chinese cabbages. Kimchi made of winter Chinese cabbage were fermented at 5$^{\circ}C$ for 40 days, of which pH, acidity, free sugar and organic acid were measured. The hardness of "Manpung" cultivar continued highly during the Kimchi fermentation at 5$^{\circ}C$. The pH and total acid in Kimchi fermentation, of the "Manpung" cultivar changed more than those of others. At the initial stage of Kimchi fermentation the major organic acid was citric acid, but lactic acid and acetic acid were increased rapidly during fermentation of Kimchi. The major organic acid of Kimchi fermented for 30 days was lactic acid, and the lactic acid contents of Kimchi prepared with "Manpung" cultivar was 6,796.6$\mu\textrm{g}$/g account for 69.6% of total organic acid.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1606-1610
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• 2002

The dynamics of fermentation were studied with Italian ryegrass ensiled in the laboratory silos. The silos were kept in the room set at 25$^{\circ}C$, and then were opened on 0.5, 1, 2, 3, 5, 7 and 14 days after ensiling, respectively. The samples were taken from three silos at each sampling time for chemical analyses. Mono-and disaccharides composition was determined for glucose, fructose and sucrose by high performance liquid chromatography. The Italian ryegrass silage succeeded to achieve lactate type fermentation; high values of lactic acid (85.83 g/kg) and lactic acid/acetic acid at the end of ensiling (14 day), low values of pH (3.74), acetic acid (5.38 g/kg), ethanol (19.20 g/kg) and $NH_3-N/Total\;N$ (75.84 g/kg), no or only small amounts of butyric acid, valeric acid and propionic acid. The fermentation dynamics showed a fast and large pH decrease caused by a fast and large production of lactic acid during the first 5 days. Mono-and disaccharides composition largely decreased within initial 0.5 day (12 h) of ensiling. Sucrose disappeared rapidly within initial 0.5 day of ensiling, and fructose and glucose contents showed an initial rise during ensiling, and then decreased gradually. These indicated that the enzymes of plant tissue were active within 2 days of ensiling, which caused the initial rise in fructose and glucose from the hydrolysis of sucrose and fructans. After 5 days of ensilage, glucose was consumed completely, suggesting that glucose was the first fermentation substrate. After 2 days of ensiling, sum amounts of lactic acid and remaining mono-and disaccharides proved to be larger than the quantity of mono-and disaccharides in the initial grass. From the facts mentioned above, it was suggested that considerable amounts of lactic acid were produced from some other substrate such as fructans than initial mono-and disaccharides.

• Journal of the East Asian Society of Dietary Life
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• v.8 no.4
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• pp.462-468
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• 1998

편이었다. 미량성분으로는 K이 다량으로 존재하였고, 2단계 발효로 제조된 포도식초는 포도양파식초 보다K, Na, Cu함량이 높게 나타났다. ^x Grape vinegar (A) and grape onion vinegar(B) added (3% of onion juice) were produced through two stages of fermentation(alcohol fermentation and acetic acid fermentation) to increase the grape's use. Grape wine which contained 5.6% alcohol was produced on the 3rd day of first stage. Then through the second stages, grape vinegar, of which total acidity was 5.37% was produced. The quality of (A) and ( B) which was produced through the two stages of fermentation was compared with the traditional grape vinegar (C, D) in the market. The content of sugar in (D) was a little higher such as 5.4 $^{\circ}$Brix than others. That of (A) and (B) was 5.13, 4.98 $^{\circ}$Brix respectively. The content of remaining alcohol in (C) was high such as 0.23% comparatively. But there was no remaining alcohol in (A) and (B). The content of acetic acid was 4.3~5.3% as a major organic acid of vinegars. The content of tartaric acid was 340.0 in (A), 315.7 in (B), 322.6 in (C) and 391.7mg% in (D). The content of lactic acid was distinctly high such as 277.4mg% in (D) There were differences such as 9.2~15.5mg% in the content of total free amino acids among grape vinegars. (D) contained 15.5mg% of total free amino acid and (B) also highly such as 12.0mg%. Potassium was high in grape vinegars. The content of potassium, sodium and copper was higher in (A) than (B).

• Korean journal of food and cookery science
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• v.32 no.1
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• pp.16-26
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• 2016

In this study, we aimed to develop functional vinegar with different levels of black garlic through two stages of fermentation. Black garlic vinegars were prepared from black garlic and water (w/w) mixed with 1:2 (BG3), 1:5 (BG6), 1:9 (BG9) and 1:11 (BG12), and adding the sugar by adjusting the soluble solids content to $14^{\circ}Brix$. The alcohol content of black garlic vinegar was 5.2-5.5% after 7 days of alcohol fermentation at $25^{\circ}C$. Acetic acid fermented was at $30^{\circ}C$ for 25 days and samples were taken at 3, 6, 9, 12, 15, 20 and 25 days. The pH of black garlic vinegar was not significantly different among the samples, but acidity was increased during fermentation. Total polyphenol contents showed irregular changes with the fermentation periods and were higher by black garlic content. At 25 days fermentation, total polyphenol contents were 18.96-56.56 mg/100 mL. Acetic acid content of black garlic vinegars was higher than other organic acids. S-allyl cysteine (SAC) contents of BG3 and BG6 were 13.03-14.54 and 1.69-2.20 mg/L, respectively. However SAC was not detected in BG9 and BG12. In 25 days fermented black garlic vinegar, the major mineral was K with a content ratio of 61-68% of total minerals. The DPPH and ABTS radical scavenging activity of 25 days fermented black garlic vinegar were stronger at higher black garlic content.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.400-406
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• 2012

To improve the hydrogen yield from biological fermentation of organic wastewater, a co-culture system of dark- and photo-fermentation bacteria was investigated. In a pure-culture system of the dark-fermentation bacterium Clostridium butyricum, a pH of 6.25 was found to be optimal, resulting in a hydrogen production rate of 18.7 ml-$H_2/l/h$. On the other hand, the photosynthetic bacterium Rhodobacter sphaeroides could produce the most hydrogen at 1.81mol-$H_2/mol$-glucose at pH 7.0. The maximum specific growth rate of R. sphaeroides was determined to be 2.93 $h^{-1}$ when acetic acid was used as the carbon source, a result that was significantly higher than that obtained using either glucose or a mixture of volatile fatty acids (VFAs). Acetic acid best supported R. sphaeroides cell growth but not hydrogen production. In the co-culture system with glucose, hydrogen could be steadily produced without any lag phase. There were distinguishable inflection points in a plot of accumulated hydrogen over time, resulting from the dynamic production or consumption of VFAs by the interaction between the dark- and photo-fermentation bacteria. Lastly, the hydrogen production rate of a repeated fed-batch run was 15.9 ml-$H_2/l/h$, which was achievable in a sustainable manner.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.665-674
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• 2019

Objective: In tropical regions, as in temperate regions where seasonality of forage production occurs, well-preserved forage is necessary for animal production during periods of forage shortage. However, the unique climate conditions (hot and humid) and forage characteristics (high moisture content and low soluble carbohydrate) in the tropics make forage preservation more difficult. The current study used natural ensiling of tropical forage as a model to evaluate silage characteristics under different temperatures ($28^{\circ}C$ and $40^{\circ}C$). Methods: Four tropical forages (king grass, paspalum, white popinac, and stylo) were ensiled under different temperatures ($28^{\circ}C$ and $40^{\circ}C$). After ensiling for 30 and 60 days, samples were collected to examine the fermentation quality, chemical composition and microbial community. Results: High concentrations of acetic acid (ranging from 7.8 to 38.5 g/kg dry matter [DM]) were detected in silages of king grass, paspalum and stylo with relatively low DM (ranging from 23.9% to 30.8% fresh material [FM]) content, acetic acid production was promoted with increased temperature and prolonged ensiling. Small concentrations of organic acid (ranging from 0.3 to 3.1 g/kg DM) were detected in silage of white popinac with high DM content (50.8% FM). The microbial diversity analysis indicated that Cyanobacteria originally dominated the bacterial community for these four tropical forages and was replaced by Lactobacillus and Enterobacter after ensiling. Conclusion: The results suggested that forage silages under tropical climate conditions showed enhanced acetate fermentation, while high DM materials showed limited fermentation. Lactobacillus and Enterobacter were the most probable genera responsible for tropical silage fermentation.