• 동아시아식생활학회지
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• 제22권2호
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• pp.264-270
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• 2012

본 연구는 pectinase 처리가 레드와인 발효와 와인의 품질에 미치는 영향을 분석하였다. 실험군과 대조군으로 구분하여 진행하였으며, pectinase 처리가 와인제조 과정에서 과즙 추출 향상, 과즙 청징 작용으로 색의 투명성과 안정성에 좋은 효과를 나타냄을 확인할 수 있었다. 포도과즙 산출량 변화를 확인한 결과에서는 pectinase가 펙틴을 분해하여 약 13%(v/v)의 포도과즙 수율 증가를 나타냈다. 와인 색의 강도와 투명성의 결과는 실험군이 대조군에 비하여 색의 적색도가 강하게 나타났으며, 색도에서는 높은 선명도를 나타냈다. 또한, 펙틴이 pectinesterase(PE)에 의해 가수분해되어 발효 중에 메탄올 함량이 증가되었다. 관능검사를 통한 와인 품질과 관련된 기호 평가에서는 실험군이 대조군에 비해 외관, 향, 맛, 촉감이 우수함을 확인할 수 있었다. 이와 같이 pectinase의 처리에 의한 레드와인 발효 시, 다당류와 펙틴의 분해에 의해 레드와인의 품질 향상을 가져올 수 있음을 확인하였다. 본 연구를 토대로 와인제조 과정에서 pectinase의 효율성을 극대화하고, 메탄올 생성량의 감소 방안, 그리고 pectinase 처리 와인의 성분 분석과 기능이 세부적으로 연구된다면 와인품질 개선에 더 큰 효과를 기대할 수 있을 것으로 판단된다.

• Journal of Animal Science and Technology
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• 제63권1호
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• pp.91-103
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• 2021

To improve the fermentation quality of silage and reduce the nutrients loss of raw materials during the ensiling process, silage additives are widely used. The effect of additives on silage is also affected by the species of crop. Therefore, this study was designed to explore the effects of formic acid (FA) and lactic acid bacterial inoculant on the quality of main summer crop silage. The experiment was consisted on split-plot design with three replications. The experiment used the main summer forage crops of proso millet ("Geumsilchal"), silage corn ("Gwangpyeongok"), and a sorghum-sudangrass hybrid ("Turbo-gold"). Treatments included silage with Lactic acid bacterial Inoculant (Lactobacillus plantarum [LP], 1.0 × 106 CFU/g fresh matter), with FA (98%, 5 mL/kg), and a control (C, without additive). All silages were stored for 60 days after preparation. All additives significantly increased the crude protein content and in vitro dry matter digestibility (IVDMD) of the silages and also reduced the content of ammonia nitrogen (NH3-N) and pH. Corn had the highest content of IVDMD, total digestible nutrients and relative feed value among silages. Compared with the control, irrespective of whether FA or LP was added, the water soluble carbohydrate (WSC) of three crops was largely preserved and the WSC content in the proso millet treated with FA was the highest. The treatment of LP significantly increased the lactic acid content of the all silage, while the use of FA significantly increased the content of acetic acid (p < 0.05). The highest count of lactic acid bacteria (LAB) was detected in the LP treatment of corn. In all FA treatment groups, the total microorganism and mold numbers were significantly lower than those of the control and LP groups (p < 0.05). In conclusion, both additives improved the fermentation quality and nutritional composition of the main summer forage crops. The application of FA effectively inhibited the fermentation of the three crops, whereas LAB promoted fermentation. So, both FA and LP can improve the quality of various species of silage.

• 동아시아식생활학회지
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• 제23권1호
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• pp.85-91
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• 2013

Korean traditional rice wine, Makgeolli, has been widely consumed and increasingly popular in Korea. In this study, we examined Makgeolli supplemented with cranberries (0, 5, 10 and 15% by rice weight) during fermentation for seven days for the various quality characteristics : pH, total acidity, soluble contents, color, reducing sugars, alcohol contents, and DPPH free radical scavenging activities, total flavonoids, microbial properties, and sensory properties. After the pH value decreased from a range of 4.40~5.63 to 3.83~3.94 up to day 3, the pH gradually increased until day 7. As fermentation proceeded, soluble contents and reducing sugar increased in most of the samples, with a temporary reduction after day 2. There were no differences in L and b color values, but the "a" value showed significant differences with the rate of cranberry added. The DPPH free radical scavenging activity and total flavonoid content of cranberry Makgeolli were higher than those of the control. After fermentation for seven days, the alcohol content ranged from 14.57 to 17.40%, while total acidity levels were within the range of 0.50 to 0.54%. Yeast cell counts increased until day 3 and then, gradually deceased. In the sensory evaluation, Makgeolli with 10% cranberry showed the highest overall acceptance.

• 한국식품과학회지
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• 제51권6호
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• pp.596-603
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• 2019

This study involved the production of specialty lager beers supplemented with Korean red ginseng extracts or Bokbunja (Korean black raspberry, Rubus coreanus Miquel) juice. The effects of the Korean red ginseng extracts or Bokbunja juice on the specific gravity, pH, yeast viability, free amino nitrogen content, reducing sugar content, color, alcohol content, turbidity, and sensory evaluation were evaluated. The alcohol content of the beers containing the extracts or juice were within the standard alcohol amounts (3.63-4.0%, v/v). The pH values of the three samples containing Bokbunja juice were lower than that of the control values. The sensory evaluation showed that the addition of Bokbunja juice was superior to the ginseng extracts, and the optimal addition time was before or after the secondary fermentation. These data indicate that the flavor and odor of the Bokbunja juice are more persistent than that of the ginseng extracts.

• Journal of Microbiology and Biotechnology
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• 제4권2호
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• pp.146-150
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• 1994

Production of poly-$\beta$-hydroxybutyrate (PHB) in fed-batch fermentation was studied. Utilization of carbon for PHB biosynthesis was investigated by using feeding solutions with different ratios of carbon to nitrogen (C/N). It was observed that at a high C/N ratio carbon source was more preferably utilized for PHB accumulation while its consumption for cellular metabolism appeared to be more favored at a low C/N value. A high cell concentration (184 g/l) was achieved when ammonium hydroxide solution was fed to control the pH, which was also utilized as the sole nitrogen source. For the mass production of PHB, two-stage fed-batch operations were carried out where PHB accumulation was observed to be stimulated by switching the ammonium feeding mode to the nitrogen limiting condition. A large amount of PHB (108 g/l) was obtained with cellular content of 80% within 50 hrs of operation.

• 한국미생물·생명공학회지
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• 제28권6호
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• pp.349-354
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• 2000

Culture conditions and nitrogen sources were optimized for production of erythritol, a natural sweetener, by Candida magnoliae M26. The optimal culture conditions were found to be culture temperature of $28^{\circ}C$, initial pH of 7, aeration of 1 vvm and agitation speed of 500 rpm in a 2.5 1 jar-fermentor. Glucose was chosen as the best carbon cource bsed on cell growth and erythritol productivity. Kight steep water(LSW) and corn steep liquor (CSL) which are by-products in starch processing from corn were tested as a nitrogen source substitute for yeast extract. The use of either LSW or CSL did not change the fermentation performance. The experimental results using LSW and CSL showed 1.5 times higher in cell growth and almost the same value in erythritol productivity com-pared with the control fermentation using yeast extract as a nitrogen source. These results suggested that either LSW of CSL could be used as a nitrogen source in a large-scale fermentation for erythritol production.

• Journal of Microbiology and Biotechnology
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• 제14권5호
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• pp.924-931
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• 2004

A bacteriocin-producing lactic acid bacterium, which strongly inhibited the Lactobacillus plantarum recognized as an important acid spoilage microorganism in kimchi fermentation, was isolated from kimchi. From morphological, physiological, sugar fermentation, biochemical tests, and l6S rDNA sequencing results, the isolate was identified as an Enterococcus sp. and designated as Enterococcus sp. K25. The bacteriocin produced by Enterococcus sp. K25 inhibited several Gram-positive bacteria, including Lb. plantarum, whereas it did not inhibit Gram-negative bacteria and yeasts. Optimal temperature and pH for the bacteriocin production were $25^\circ{C}$ and 5.5, respectively. Enterococcus sp. K25 was applied to kimchi manufacturing alone and together with other preservatives (i.e., chitosan and fumaric acid). In addition, growth of lactic acid bacteria, pH, and titratable acidity (TA) were measured during aging at $5^\circ{C}$ and $10^\circ{C}$. Inoculation of Enterococcus sp. K25 together with fumaric acid showed the most synergistic effect on extension of kimchi shelf-life. Compared to control (no addition), the treatment prolonged the kimchi shelf-life up to 6 days, whereupon the eight-point TA value recognized as the edible limit was reached.

• Asian-Australasian Journal of Animal Sciences
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• 제10권4호
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• pp.357-363
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• 1997

The effect of replacement of cotton seed meal (CSM), with various levels and sources of non-protein nitrogenous (NPN), substances on in vitro ruminal fermentation were studied. Cotton seed meal, in control ration provided nitrogen equivalent to 12.5 percent crude protein while in experimental ration was replaced at 30, 50 & 70 percent levels with urea, diammonium phosphate (DAP) and biuret, respectively. The results of incubation upto 48 hours indicated an improvement in digestibility by replacement of CSM with urea and biuret upto 50 percent protein equivalent, but not with DAP. Bacterial count from cultures containing 50% nitrogen from biuret was significantly higher than DAP, urea and CSM. Various sources of nitrogen produced $NH_3-N$ in increasing order of CSM, biuret, DAP and urea. Increasing levels of NPN resulted in progressive increase in the levels of $NH_3-N$. The levels of various NPN sources had no effect on pH. However, the pH values determined for urea and CSM were higher than biuret and DAP.

• 농업과학연구
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• 제37권3호
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• pp.405-412
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• 2010

This study was focused on finding the potential of hot water extract of bamboo shoot (Sasa borealis Makino) on the fermentation of Kimchi made with Chinese cabbage. The properties of Kimchi were examined up to 28 days of storage. The pH and acidity decreased regardless of treatments and showed no significant difference between treatments. There was a decreasing tendency of both total and reducing sugars in kimchi but the addition of bamboo extract did not affect the soluble sugar levels. Interestingly, bamboo extracts affected the lactic acid fermentation and ripening, resulting in the increase of lactic acid in bamboo extract treatment. Number of total bacterial cell of additive group is higher than control one, probably due to the stimulative effect of bamboo extract on bacterial growth. Level of lactic acid bacteria was also higher in the additive group, thus, it is considered that bamboo extract appeared to enhance the proliferation of lactic acid bacteria. The acceptability of treated Kimchi was higher in general. And results of intensity evaluation in color and texture were higher as well by addition of bamboo extract.

• Food Science and Biotechnology
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• 제15권6호
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• pp.884-888
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• 2006

In this study, we have attempted to characterize the effects of encapsulated mustard oil with regard to the extension of the shelf life of kimchi. The quantity of mustard oil or encapsulated mustard oil added to the brined cabbage in this study was 0.05%(w/w). Overall, the fermentation processes in the encapsulated mustard oil-added kimchi (EMO) and mustard oil-added kimchi (MO) occurred at a slower rate than in the controls. The periods during which the MO and EMO kimchi samples were edible were prolonged for more than two weeks, according to measurements of pH, total acidity, and microbial changes. The overall acceptability of EMO was superior to MO throughout the entirety of the fermentation period. Sensory evaluation verified that EMO yielded a more favorable product than the MO and control varieties. Encapsulated mustard oil can be employed as a natural food additive to prolong the shelf life of kimchi, via an induced delay of the fermentation process.