• 한국식생활문화학회지
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• 제16권5호
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• pp.431-441
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• 2001

To develop the low-temperature and long-term fermented kimchi, kimchi was prepared according to the recipe of a specific ratio of major and minor ingredients and adjusted its salinity to 3.7%. Prepared kimchi fermented at $15{\pm}1^{\circ}C$ for 24 hours and transferred and fermented in a refrigerator only used to make low-temperature and long-term fermented kimchi at $-1{\pm}1^{\circ}C$ for 30 weeks. During 30 weeks of fermentation the changes in physicochemical and microbiological properties of low-temperature and long-term fermented kimchi were studied. The initial pH of 6.47 decrease gradually and dropped to pH 4.0 after 14 weeks of fermentation, and then it maintained at same level. Acidity increased to 0.49% on 2 weeks of fermentation and kept at 0.47 $\sim$0.50% during 2 to 30 weeks fermentation. Salinity was slightly increased at early stage and started to decrease on 4 weeks of fermentation, and then it did not change. The change of reducing sugar content was closely related to the trend of pH change with a very high correlation coefficient(r =0.912). Lactic acid, citric acid, malic acid, succinic acid and acetic acid were major organic acids contained in low-temperature and long-term fermented kimchi. Vitamin C content decreased at initial stage of fermentation and then slightly increased up to the maximum of 22.3 mg% on 8weeks of fermentation. In color measurement, L value continued to increase during the fermentation and reached at the highest of 55.45 on 22 weeks of fermentation, and a and b values of 3.62 and 4.54 also increased to 31.26 and 37.32 on 30 weeks of fermentation, respectively. Total microbial count increased slowly from beginning and was the highest on 4 weeks of fermentation, and then began to decrease slowly. Count of Lactobacillus spp. was highest after 6weeks, but count of Lactobacillus spp. was highest on 2 weeks of fermentation, and then both showed a slow decrease. Yeast count wasn't increased until 4 weeks of fermentation and then increased rapidly to get the highest on 10 weeks of fermentation.

• Food Science and Biotechnology
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• 제16권6호
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• pp.924-927
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• 2007

This study addresses the quality characteristics of commercial baechukimchi by analyzing its physicochemical characteristics and sensory properties in relation to fermentation time and temperature. The salinity of baechukimchi increased to 3.01% after 45 days of fermentation at 2 and $5^{\circ}C$, but decreased to 2.81% by 105 days. The pH decreased gradually at the beginning of fermentation, but decreased after 45 days. The acidity differed most between kimchi fermented at $2^{\circ}C$ (0.36%) and $5^{\circ}C$ (0.48%) at 45 days of fermentation. The vitamin C content was 8.47 mg% in kimchi fermented at both 2 and $5^{\circ}C$ on the day of initial production, then peaked after 45 to 60 days at 14.10 mg%, and decreased thereafter. The total microbial count gradually increased during the first 75 days of fermentation. The appearance and overall acceptability of baechukimchi were highest after 90 days of fermentation at $2^{\circ}C$ and after 60 days of fermentation at $5^{\circ}C$.

• 한국식품저장유통학회지
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• 제16권6호
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• pp.804-809
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• 2009

최근, 저온 장시간 발효된 묵은지에 대한 소비가 증가하고 있다. 본 논문에서는, 저온($5^{\circ}C$)에서 46주 동안 발효된 묵은지의 pH, 산도, 유기산, 생균수, 아미노산, polygalacturonase (PG) 활성 등을 분석하였다. 10주 발효한 김치에서는 pH 4.1, 산도 0.99%를 나타낸 반면, 46주 발효한 김치에서는 pH 3.9, 산도 1.29%를 보였다. 한편, 10주에서 46주로 발효 기간이 증가하면서, 젖산, 젖산/초산비, Lactobacillus species/Leuconostoc species비 등은 증가한 반면, 호기성 세균, 효모, Lactobacillus species, Leuconostoc species, 유리아미노산, PG 효소 활성은 감소하였다.

• Preventive Nutrition and Food Science
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• 제12권1호
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• pp.46-50
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• 2007

Physicochemical properties of commercial long-term fermented kimchies which are widely available in Korea were investigated. The commercial long-term fermented kimchies were fermented almost more than 6 months. Average values for saltiness, pH and acidity of the long-term fermented kimchies were $3.0{\pm}0.5%$, $4.0{\pm}0.2$, and $1.88{\pm}0.76%$, respectively. The long-term fermented kimchi showed similar Leuconostoc sp. and Lactobacillus sp. counts as baechu kimchi ripened properly during fermentation. The amount of Leuconostoc sp. and Lactobacillus sp. of the long-term fermented kimchi were $10^{7\sim8}$ CFU/mL and $10^{4\sim7}$ CFU/mL, respectively. The long-term fermented kimchi showed $0.32{\pm}0.18$ lightness, $1.73{\pm}0.98$ redness, $0.52{\pm}0.31$ yellowness. Long-term fermented kimchi showed higher lightness, redness, yellowness than well-fermented standardized baechu kimchi. Breaking strength of long-term fermented kimchi was higher than that of well-fermented standard baechu kimchi.

• 한국초지조사료학회지
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• 제12권1호
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• pp.19-25
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• 1992

This experiment was conducted to investigate chemical composition change and fermentation characteristics of orchardgrass, alfalfa or corn silage in the airtight silo for one year of storage. Two trials were conducted for two years. Fermentation characteristics of silages were evaluated by color, oder, texture and taste. Chemical composition of corn silage was not changed, and fermentation characteristics of this silage was favorable for 7 months of storage from December to June of the following year. In the aspect of dry matter loss and fermentation characteristics of silages, it is essential to maintain less than 70 or 60% of moisture contents in orchardgrass silage or alfalfa silage, respectively, for long term storage and feed quality stabilization. It is suggested that wilting treatment of orchardgrass or alfalfa and moisture contents of these silages are most important factors to determine silage quality.

• 한국초지조사료학회지
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• 제12권1호
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• pp.19.1-19.1
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• 1992

This experiment was conducted to investigate chemical composition change and fermentation characteristics of orchardgrass, alfalfa or corn silage in the airtight silo for one year of storage. Two trials were conducted for two years. Fermentation characteristics of silages were evaluated by color, oder, texture and taste. Chemical composition of corn silage was not changed, and fermentation characteristics of this silage was favorable for 7 months of storage from December to June of the following year. In the aspect of dry matter loss and fermentation characteristics of silages, it is essential to maintain less than 70 or 60% of moisture contents in orchardgrass silage or alfalfa silage, respectively, for long term storage and feed quality stabilization. It is suggested that wilting treatment of orchardgrass or alfalfa and moisture contents of these silages are most important factors to determine silage quality.

• 한국식생활문화학회지
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• 제35권5호
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• pp.450-458
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• 2020

This study examined the optimal temperature and time conditions to maintain high quality Dongchimi during the fermentation and storage period. Dongchimi was fermented at low (5℃), medium (10 and 15℃), and high (20℃) temperatures until the acidity reached 0.2, 0.3, and 0.4%. respectively. From the consumer's preference test enrolling five consumers, Dongchimi fermented at 15℃ until an acidity of 0.3% (for approximately six days) was evaluated to be the optimal status because of its high score of overall acceptance, taste, and odor of consumers. To determine the optimal storage temperature of fermentation, Dongchimi was stored at three different temperatures (-1, 2, 5℃) for four weeks after fermenting at 15℃ for six days. During the storage period, most of the physicochemical properties (pH, acidity, reducing sugar content, and organic acid) and microbiological properties changed significantly in the 2 and 5℃ groups, resulting in a significant change in descriptive sensory analysis of Dongchimi. These results indicate that fermentation at 15℃ and storage at -1℃ for Dongchimi enables it to maintain the best quality for a long time.

• 한국식생활문화학회지
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• 제20권4호
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• pp.426-432
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• 2005

김치의 조직감에서 cutting force는 제조당일 8.4kgf로 가장 큰 값을 나타낸 후 1일후 40%의 감소가 일어난 후 그 후 서서히 감소하다가 14주째에 급격한 증가를 보인 후 다시 감소하였다. 이러한 절단력은 질긴 정도와 씹힘성을 나타내 주고 있는 바 compression force 시험에서도 gumminess와 chewiness가 각각 제조 1일 후 급속히 감소하였다가 14주에 다시 증가하고 있는 것으로 나타났다. 텍스쳐 인자들 간의 상관관계는 씹힘성과 질김성이 r= 0.879로 다른 인자들보다도 가장 높은 정의 상관관계를 나타냈으며 씹힘성과 경도(r=0.570), 씹힘성과 응집성(r=0.591), 씹힘성과 탄성(r=0.513), 질김성과 경도 (r=0.503)도 정의 상관관계를 보여 주었다. 김치의 관능평가에서 외관, 짠맛, 경도는 제조당일 김치가 가장 높은 평가를 받았고 전체적인 기호도는 14주 동안 발효된 김치가 가장 높은 평가를 받았으며 18주 발효된 김치의 경우 탄산미와 신맛에 대해 높은 평가를 나타냈다. 관능검사를 통한 taste간의 상관관계는 신맛과 off-flavor(r=0.805), 신맛과 탄산미(r=0.813)는 매우 정적인 상관관계를 보였으며, 탄산미와 off-flavor(r=0.661), 짠맛과 단단함(r=0.530)은 정적인 상관관계를 보였다(p<0.001). Taste와 조직감에 대한 상관관계는 짠맛과 단단함이 r=0.559로 정의 상관관계를 보였고, off-flavor와 단단함(r=-0.657), 탄산미와 단단함(r=-0.540), 신맛과 단단함(r=-0.651)은 역의 상관관계를 나타내었다. 조직감간의 상관관계는 아삭아삭한 정도와 뻣뻣한 정도(r=0.522)가 정의 상관관계를 나타내었다. 결론적으로 3.7% 염도의 김치를 제조하여 $15{\pm}1^{\circ}C$에서 24시간 동안 예비 숙성시키고 $-1{\pm}1^{\circ}C$의 김치전용냉장고에서 30주 동안 숙성시키면서 묵은 김치의 텍스쳐와 관능적 특성을 실험한 결과 묵은 김치제조를 위한 최적 발효기간은 18주인 것으로 사료되었다.

• 한국미생물·생명공학회지
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• 제24권6호
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• pp.717-725
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• 1996

We have developed an efficient immobilized cell separator for continuous operation of immobilized fungal cell cultures, and applied this separator to actual fermentation process for the production of cyclosporin A (CyA), a powerful immunosuppressant. In the experiments employing highly viscous polymer (carboxymethyl cellulose) solution, the decantor showed good separating performances at high solution viscosites and fast dilution rates. Air duct and cylindrical separator installed inside the decantor turned out to play key roles for the efficient separation of the immobilized cells. By installing the decantor in an immobilized perfusion reactor system (IPRS), continuous immobilized culture was stably carried out even at high dilution rate for a long period, leading to high productivities of free cells and CyA. Almost no immobilized biomass existed in effuluent stream of the IPRS, demonstrating the effectiveness of the decan- tor system for a long-term continuous fermentation. It was noteworthy that we could obtain these results despite of the unfavorable fermentation conditions, i.e., reduced density of the biosupports caused by overgrowth of cells inside the bead particles and existence of high density of suspended fungal cells (10g/l) in the fermentation broth.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.514-515
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• 1989