• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.353-358
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• 1999

We produced the apple vinegar with only apple fruits, no adding sugar and others through two stages fermentation(alcohol fermentation and acetic acid fermentation). At the first stage, apple wine contained 5% alcohol was produced at the 5th day. And through the second stage, acetic acid fer mentation, apple vinegars of which total acidity is 5.88% were produced. In comparision with com mercial vinegars for physicochemical quality, it was the lowest in total acidity. But contents of oxalic, tartaric, malic, citric, succinic acid in it were higher than other vinegars. Especially the content of malic acid in it was higher 5 times than other vinegars. Malic acid was known that it was abundant in apple fruits. Also the contents of free amino acids were distinctly high such as 21.97mg% in two stages fermented apple vingars. Potassium content in it was higher 4 times than other vinegars. So it was supposed that two stages fermented vinegar had much higher quality than commercial vinegars.

• 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).

• Food Science and Preservation
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• v.5 no.4
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• pp.374-379
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• 1998

A vinegar was prepared from uncleaned rice by two step fermentation, alcohol fermentation followed by acetic acid fermentation. The contents of alcohol reached to 10.8% during the alcohol fermentation of uncleaned rice with nuruk, and acidity reached to 5.78% during the acetic acid fermentation. Acidity and pH of vinegar of two step fermentation were higher than those of commercial vinegars. 'L' value(Light) of the vinegar was lower, 'a' and 'b' value were higher than those of commercial vinegars. The contents of acetic acid, malic acid, citirc acid and tartaric acid were hish in organic acid of vinegars. The content of each ofganic acid in vinegars was remarkably different. The content of free amino acids was 2199.7${\mu}\ell$/ml in the vinegar produced by two step fermentation which is higher than that of others.

• Food Science and Preservation
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• v.6 no.2
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• pp.233-238
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• 1999

This study was determined changes of components of sweet and astringent persimmon vinegars by two stages fermentation. Free sugars of persimmon juices before alcohol fermentation were mainly composed of glucose, fructose and sucrose. The content of glucose, fructose and sucrose of sweet persimmon juice was 6.60, 6.12 and 1.74%, respectively, and those of astringent persimmon was 5.63, 5.21, 0.62%, respectively. The contents of free sugar decreased continuously during fermentation. Major organic acids of persimmon juices were acetic, galacturonic, malic, citric and ascorbic acid. Alcohols of persimmon juices was detected methanol, ethanol, iso-propylalcohol, n-propylalcohol and iso-butylalcohol at the initial fermentation. The contents of alcohols increased continuously up to 4days of fermentation but their contents except ethanol decreased slightly at 5th day of fermentation. Contents of free amino acid were higher in sweet persimmon than those in astringent persimmon. Volatile components increased during acetic acid fermentation.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.10
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• pp.1374-1380
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• 2012

The changes in yields and nutritive composition of whole crop wheat (Triticum aestivum L.) during maturation and effects of maturity stage and lactic acid bacteria (LAB) inoculants on the fermentation quality and aerobic stability were investigated under laboratory conditions. Whole crop wheat harvested at three maturation stages: flowering stage, milk stage and dough stage. Two strains of LAB (Lactobacillus plantarum: LAB1, Lactobacillus parafarraqinis: LAB2) were inoculated for wheat ensiling at $1.0{\times}10^5$ colony forming units per gram of fresh forage. The results indicated that wheat had higher dry matter yields at the milk and dough stages. The highest water-soluble carbohydrates content, crude protein yields and relative feed value of wheat were obtained at the milk stage, while contents of crude fiber, neutral detergent fiber and acid detergent fiber were the lowest, compared to the flowering and dough stages. Lactic acid contents of wheat silage significantly decreased with maturity. Inoculating homofermentative LAB1 markedly reduced pH values and ammonia-nitrogen ($NH_3$-N) content (p<0.05) of silages at three maturity stages compared with their corresponding controls. Inoculating heterofermentative LAB2 did not significantly influence pH values, whereas it notably lowered lactic acid and $NH_3$-N content (p<0.05) and effectively improved the aerobic stability of silages. In conclusion, considering both yields and nutritive value, whole crop wheat as forage should be harvested at the milk stage. Inoculating LAB1 improved the fermentation quality, while inoculating LAB2 enhanced the aerobic stability of wheat silages at different maturity stages.

• Journal of Microbiology and Biotechnology
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• v.22 no.7
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• pp.960-966
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• 2012

The diversity and composition of yeast populations may greatly impact wine quality. This study investigated the yeast microbiota in two different types of wine fermentations: direct inoculation of a commercial starter versus pied de cuve method at an industrial scale. The pied de cuve fermentation entailed growth of the commercial inoculum used in the direct inoculation fermentation for further inoculation of additional fermentations. Yeast isolates were collected from different stages of wine fermentation and identified to the species level using Wallersterin Laboratory nutrient (WLN) agar followed by analysis of the 26S rDNA D1/D2 domain. Genetic characteristics of the Saccharomyces cerevisiae strains were assessed by a rapid PCR-based method, relying on the amplification of interdelta sequences. A total of 412 yeast colonies were obtained from all fermentations and eight different WL morphotypes were observed. Non-Saccharomyces yeast mainly appeared in the grape must and at the early stages of wine fermentation. S. cerevisiae was the dominant yeast species using both fermentation techniques. Seven distinguishing interdelta sequence patterns were found among S. cerevisiae strains, and the inoculated commercial starter, AWRI 796, dominated all stages in both direct inoculation and pied de cuve fermentations. This study revealed that S. cerevisiae was the dominant species and an inoculated starter could dominate fermentations with the pied de cuve method under controlled conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1021-1027
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• 1997

$CO_2$production in fermentation of dongchimi was measured and interrelated with changes in pH and titratable acidity. The effects of salt content and temperature on $CO_2$production rate were analysed. Fermentation of dongchimi showed drastic pH decrease in early stage and subsequent levelling off around 3.9, with linearly increased acidity up to 0.3~0.4% optimum quality. $CO_2$production of dongchimi could be analysed to consist of two consecutive stages of constant rate. The first stage $CO_2$production of higher rate moved to the second stage of lower rate when acidity rose beyond 0.3%. When compared to those of 1 and 2% salt content, dongchimi of 3% salt showed lower $CO_2$production rate in the 1st stage and slower acidity change through the whole fermentation period. However, it resulted in the product of highest $CO_2$accumulation at optimal ripeness because of consistent $CO_2$production of longer 1st stage period and relatively high $CO_2$production rate in 2nd stage. $CO_2$production depended on temperature less compared to acidity change(activation energy: 57.3 and 44.3kJ/mol for $CO_2$production of 1st and 2nd stages, respectively; 79.3kJ/mol for acidity change), which means higher ratio of $CO_2$production rate relative to acidity increase at lower temperature. Slower increase in acidity at low temperature also was shown to extend the period of 1st stage $CO_2$production. Therefore, low temperature fermentation was effective in producing the high $CO_2$content dongchimi at adequate acidity, which is desirable organoleptically.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1079-1084
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• 2002

Changes in components of onion vinegar during two-stage fermentation were investigated. One sample group (A) was prepared with onion juice by extraction and concentration (15 brix), and the other group (B) was prepared using the same method but supplemented with sucrose. Comparison of glucose (4.1%), fructose (4.2%), and sucrose (0.6%) found in A as major sugars with those (3.2, 3.3, and 4.6%, respectively) of B showed a significant difference in sucrose concentration. During alcohol fermentation, S. kluyvery DJ97 consumed these sugars completely. At 36 hr of alcohol fermentation, concentrations of reducing and total sugars decreased to 0.5 and 0.8%, in A, and 0.4 and 0.6%, in B, respectively. No further changes were detected in the concentrations of these sugars thereafter. From 12 hr of fermentation, alcohol concentrations in groups A and B increased markedly, maximizing at 7.0% at 36 hr A and at 8.2% at 48 hr in B, and finally decreased thereafter in both groups. The detected alcohol components were ethanol, acetaldehyde, methanol, n-propyl alcohol, iso-butanol, and iso-amyl acohol. During acetic acid fermentation, the concentration of acetic acid as the major organic also increased significantly in both groups (4,776.72 and 4,894.93 mg% in A amd B, respectively). Other organic acid contents such as malic and succinic acids were higher in A than B. these results indicate that vinegar is better produced in onion extract with no sucrose supplementation based on its organic acid contents.

• Microbiology and Biotechnology Letters
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• v.10 no.2
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• pp.155-162
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• 1982

A cell-recycled continuous fermentation process was studied to produce ethanol from molasses using Sacchoromyces uvarum ATCC26602 at 35 $^{\circ}C$. The fermentation system was divided into two stages in order to reduce the inhibitions of ethanol and substrate for cell growth and fermentation rate. The first reactor was aerated at the rate of 0.12 vvm whilst the second was kept anaerobic. In medium composition studies, it was revealed that inorganic nutrient supplement to the diluted molasses with 14% fermentable sugar was not needed for the fermentation, however, phosphate limitation was observed when cell propagation was contemplated. By using the cell-recycled continuous fermentation system, 14.5 hour was required to produce 8.4-9.0% (v/v) of ethanol from diluted molasses containing 14% of fermentable sugar. The ethanol productivity was 6.2g/$\ell$hr with the yield of 88.1-94.4% to the theoretical value.

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