• 한국버섯학회지
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• 제15권4호
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• pp.237-243
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• 2017

누에동충하초의 유효성분 증가 및 흡수력 향상을 위한 발효식품을 개발하기 위하여 유산균, 고초균, 낫토균, 효모 등 4종의 미생물을 이용하여 각 미생물을 사용할 수 있는 다양한 조합으로 단 발효와 복합 발효를 시도한 15가지의 모든 경우의 수를 미생물 접종 조건으로 하여 발효산물을 제조하였다. 각 조건의 발효산물의 당도, 환원당, 단백질 함량 등 기본 성분의 함량 변화와 총폴리페놀, 총플라보노이드, 항산화 활성, tyrosinase 저해활성, 혈전 용해 활성 등 건강식품 개발에 요구되는 항목들의 활성을 분석하였다. 그 결과 대부분의 발효산물에서 환원당과 단백질 등 함량은 다소 낮아졌으나 효모를 이용하여 발효한 발효산물에서는 당도가 높아져 단맛이 증가하였으며, 총 폴리페놀과 항산화 활성은 발효 전 누에동충하초에 비해 발효산물에서 증가를 보이지는 않았지만 총플라보노이드와 tyrosinase 저해활성 및 혈전용해 활성에서는 발효에 의해 증가효과를 나타냈다. 특히, 효모를 이용한 복합 발효균에서 대부분 활성의 증가를 나타냈으나 효모만을 이용한 단 발효에서는 그 활성의 증가를 확인할 수 없었다. 따라서 유산균과 효모를 이용한 복합 발효 조건에 대한 추가적인 연구를 통해 더욱 탁월한 건강기능효과를 가지는 누에동충하초 발효식품을 개발한다면 국민 건강 증진 및 양잠농가의 소득증대에도 기여할 것으로 기대한다.

• 한국식품조리과학회지
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• 제12권3호
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• pp.300-304
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• 1996

증편반죽의 증자과정 중에 일어나는 변화양상을 규명하고자 발효시간을 0에서 10시간까지 달리한 증편제품들을 비교 검토하였다. 발효시간에 따른 증편제 품의 화학적 성질들의 변화양상은 반죽시료의 경우와 유사하였으나 증자과정 중 pH는 약간 증가한 반면에 적정산도, lactic acid, 총 당과 환원당, 가용성 단백질 과 총 유리아미노산은 감소하였고 특히 환원당이 크게 감소하였으며 또한 유리아미노산의 종류별로는 다소 증가 혹은 감소하여 일정한 경향을 보이지 않았다.

• Animal Bioscience
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• 제36권2_spc호
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• pp.364-373
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• 2023

The gastrointestinal (GI) tract of ruminants contains diverse microbes that ferment various feeds ingested by animals to produce various fermentation products, such as volatile fatty acids. Fermentation products can affect animal performance, health, and well-being. Within the GI microbes, the ruminal microbes are highly diverse, greatly contribute to fermentation, and are the most important in ruminant nutrition. Although traditional cultivation methods provided knowledge of the metabolism of GI microbes, most of the GI microbes could not be cultured on standard culture media. By contrast, amplicon sequencing of 16S rRNA genes can be used to detect unculturable microbes. Using this approach, ruminant nutritionists and microbiologists have conducted a plethora of nutritional studies, many including dietary interventions, to improve fermentation efficiency and nutrient utilization, which has greatly expanded knowledge of the GI microbiota. This review addresses the GI content sampling method, 16S rRNA gene amplicon sequencing, and bioinformatics analysis and then discusses recent studies on the various factors, such as diet, breed, gender, animal performance, and heat stress, that influence the GI microbiota and thereby ruminant nutrition.

• 한국해양바이오학회지
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• 제2권1호
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• pp.11-22
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• 2007

This aims to review natural products transformed by mimic intestinal metabolisms with microorganisms and hydrolytic enzymes, which exhibit enforced biological activity, higher extraction yield and identification of active components. In the process, transformation to the smaller active compounds with enzymes and microbes mimics the pharmacological action of natural products by intestinal bacteria. In order to establish conditions for the fermentation and enzyme reaction, it is required to choose several natural products for biotransformation and investigate the optimal conditions for the fermentation or the enzyme reaction such as composition, temperature, pH, inoculum, and cultivation time. It is expected an increase of the internal absorption of the active materials without regard to the intestinal microbes or its ability through biosynthesis of the active materials by the microbes and enzymes. And this techniques can be applied to biotransformation of natural products such as sesaminol, resveratrol, 1-deoxy nojirimycin, naringenin, quercetin, and baicalin and to the metabolism study using the animal model.

• Journal of Microbiology and Biotechnology
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• 제23권4호
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• pp.572-578
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• 2013

Azotobacter vinelandii, a strict aerobic nitrogen-fixing bacterium, has been extensively studied with regard to the ability of $N_2$-fixation due to its high expression of nitrogenase and fast growth. Because nitrogenase can also reduce cyanide to ammonia and methane, cyanide degradation by A. vinelandii has been studied for the application in the bioremediation of cyanide-contaminated wastewater. Cyanide degradation by A. vinelandii in NFS (nitrogen-free sucrose) medium was examined in terms of cell growth and cyanide reduction, and the results were applied for cyanide-contaminated cassava mill wastewater. From the NFS medium study in the 300 ml flask, it was found that A. vinelandii in the early stationary growth phase could reduce cyanide more rapidly than the cells in the exponential growth phase, and 84.4% of cyanide was degraded in 66 h incubation upon addition of 3.0 mM of NaCN. The resting cells of A. vinelandii could also reduce cyanide concentration by 90.4% with 3.0 mM of NaCN in the large-scale (3 L) fermentation with the same incubation time. Finally, the optimized conditions were applied to the cassava mill wastewater bioremediation, and A. vinelandii was able to reduce the cyanide concentration by 69.7% after 66 h in the cassava mill wastewater containing 4.0 mM of NaCN in the 3 L fermenter. Related to cyanide degradation in the cassava mill wastewater, nitrogenase was the responsible enzyme, which was confirmed by methane production. These findings would be helpful to design a practical bioremediation system for the treatment of cyanide-contaminated wastewater.

• Asian-Australasian Journal of Animal Sciences
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• 제15권4호
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• pp.602-609
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• 2002

Lao-chao is a traditional Chinese fermented rice product with a sweet and fruity flavor, containing high levels of glucose, a little alcohol and milk-clotting characteristics. In order to optimize commercial production of lao-chao, Rhizopus javanicus and Saccharomyces cerevisiae were selected as the mold and yeast starter, respectively. A commercial mixed starter (chiu-yao) was used as control. Fermentation of the experimental combination revealed a sharp drop in pH (to 4.5) on the fourth day, remaining constant thereafter. Content of reducing sugars gradually decreased throughout the entire fermentation period. Of the free amino acids, higher quantities of alanine, leucine, proline, glutamic acid, glutamine and $NH_3$ were noted. For sugars, glucose revealed the highest concentration, while organic acid levels, including those for oxalic, lactic, citric and pyroglutamic acid, increased throughout the fermentation period. Twenty-one compounds were identified by gas chromatography from aroma concentrates of the lao-chao culture filtrate, prepared using the headspace method. For the flavor components, higher quantities of ethanol, fusel oil and ester were determined in both culture filtrates. In regard to the evaluation of yogurt-like product, there were significant differences in alcoholic smell, texture and curd firmness.

• 한국미생물·생명공학회지
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• 제9권4호
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• pp.253-261
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• 1981

Fermented foods available in Korea may be classified into four groups, namely, fermented soybean products, fermented cereal products, fermented vegetable products, and fermented fishery products based on raw materials used. The representative fermented foods based on soybean are Kanjang(soysauce), Doenjang(fermented soybean pastes), and Kochujang(red pepper added-fermented soybean paste). Such fermented products are made using Meju(functioning as a starter and prepared by fermentation of steamed soybean mash) as an essential ingredient, and used widely as a soup base and/or in seasoning side-dishes for everyday meals year around. Excepting Sikhae, all fermented products based on rice and other cereal grains are of alcoholic nature. Takju (Makgeolli) used to be made using rice as the major raw material, however, mainly due to the shortage of rice in recent years, other cereals, such as, barely, corn, and wheat flours are also used to replace rice today. Owing to such changes in the raw materials. the popularity of Takju has been somewhat reduced, yet it is still widely consumed in rural areas. Although Chungju is a popular rice wine with superior qualify over Takju, the amount consumed is considerably limited. The highest qualify rice wine, Bupju, in particular, is made by a low temperature fermentation using glutinous rice. Kimchi is an unique fermented vegetable product of long tradition in Korea. Although it was for consumption mainly in winter season serving as a source of vitamins, today it is widely used throughout the year. Except Kkakdugi and Dongchimi, all of the fermented vegetable products contain salted Korean cabbage as an essential item, while they abound in varieties depending on material composition and methods of processing, and also on seasons and localities Next to Kimchi in this category is Kkakdugi made of raddish in popularity and quantity consumed. The four groups of fermented food products described above are reviewed in some detail and evaluated in terms of their nutritional significances, processes and microorganisms involved. and their commercial potentials. Jeotkal (or Jeot) is a name given to all fermented products of fishery origin. A number of Jeot can be prepared by adding salt and allowing fermentation to the raw materials such as shrimp, anchovy octopus, clam, oyster, etc.

• Asian-Australasian Journal of Animal Sciences
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• 제27권7호
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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.

• Preventive Nutrition and Food Science
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• 제10권4호
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• pp.349-352
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• 2005

The growth inhibitory effect of wheat grain, fermented wheat grain products, red pepper powder and kochujang was examined in AGS human gastric adenocarcinoma cells. The kochujang samples were prepared by mixing red pepper powder and each fermented wheat grain products, such as first fermented wheat grain (FFWG), second fermented wheat grain (SFWG) and final fermented wheat grain (FiFWG). The methanol extract of FiFWG showed the highest growth inhibitory effects. In order to investigate the effects of fermented wheat grain products at each stage of fermentation on anticancer activity, the kochujang prepared with red pepper powder and each of FFWG, SFWG and FiFWG were fermented until reaching pH 5.1. The kochujang adjusted to pH 5.1 by fermentation increased the growth inhibitory effect; however, the kochujang prepared with FiFWG showed the highest effect. Increased fermentation time increased the growth inhibitory effect of kochujang when prepared with FiFWG. These results suggested that the anticancer effect of the kochujang on the gastric cancer cells was affected by the fermentation periods of the wheat grains. The well-fermented end products of the wheat grains seem to be one of the major components that showed anticancer activity of kochujang.

• Journal of Dairy Science and Biotechnology
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• 제37권2호
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• pp.83-93
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• 2019

Food spoilage by fungi is responsible for considerable food waste and economical losses. Among the food products, fermented dairy products are susceptible to deterioration due to the growth of fungi, which are resistant to low pH and can proliferate at low storage temperatures. For controlling fungal growth in dairy products, potassium sorbate and natamycin are the main preservatives used, and natamycin is approved by most countries for use in cheese surface treatment. However, a strong societal demand for less processed and preservative-free food has emerged. In the dairy products, lactic acid bacteria (LAB) are naturally present or used as cultures and play a key role in the fermentation process. Fermentation is a natural preservation technique that improves food safety, nutritional value, and specific organoleptic features. Production of organic acids is one of the main features of the LAB used for outcompeting organisms that cause spoilage, although other mechanisms such as antifungal peptides obtained from the cleavage of food proteins and competition for nutrients also play a role. More studies for better understanding these mechanisms are required to increase antifungal LAB available in the market.