The study was focused to investigate the effect of nitrosodimethylamine (NDMA) formation due to nitrosamine (NA) precursor and/or inhibitor addition to Kimchi during the fermentation of Kimchi at room temperature (16±2℃). The addition of nitrite and dimethylamine (DMA) to Kimchi showed the average 32-fold (21.3-113.9 ug/kg) and 9-fold (1.3-40.3 ug/kg) higher NDMA formation than control (0-5.6 ug/kg), respectively. Also, the addition of both nitrite and DMA resulted in the increase of NDMA formation to average 42-fold (39.4-155.7 ug/ kg) higher than control. On the other hand, the addition of 4 mM ascorbic acid to Kimchi with nitrite and DMA inhibited the formation of NDMA down to 71.3% of control. However, the addition of cysteine and erythorbic acid affected no inhibition to NDMA formation during the test. The addition of sodium sulfite increased NDMA formation. Accordingly, this showed that the amount of ascorbic acid generated during Kimchi fermentation played an important inhibition role for NA formation.

The effects of kind of vegetables and of the kind and amounts of fermented fish sauce on the formation of nitrosamine (NA) during kimchi fermentation were investigated. Kimchies made of Chinese cabbage, cucumber, and radish with fermented shrimp, anchovy and liquid sauces were fermented at 4℃ for 6 weeks and the changes in the content of nitrate, nitrite, trimethylamine (TMA), dimethylamine (DMA) and NA were studied. Nitrate content in kimchies made of Chinese cabbage, cucumber, and radish increased at the initial period of fermentation, but it decreased at the later period. Nitrite was not detected at the later period of kimchi fermentation. Overall, there have not been great changes in the contents of nitrite and nitrate. However, there have been considrable changes in the contents of TMA and DMA as fermentation progressed. Only nitrosodimethylamine (NDMA) at the level of 0.5-10.3 ug/kg was formed in three kinds of kimchies. More NDMA was formed in radish and cucumber kimchies than in Chinese cabbage kimchi. The pH was lowered faster in radish and cucumber kimchies than in Chinese cabbage kimchi. More NDMA was formed in Chinese cabbage kimchi made with fermented shrimp sauce than those with anchovy or liquid sauces. Shrimp sauce contained higher amount of DMA than anchovy and liquid sauces. The contents of NDMA tended to increase as the amount of shrimp sauce increased. The kind and amount of fermented fish sauce used for kimchi preparation may be an important factor affecting the formation of NDMA.

This experiment was conducted to evaluate effects of wilting and additives on fermetation characteristics, quality and aerobic stability of silage of rye(Seca1e cereale L.) harvested at the early heading stage. Harvested rye was wilted or mixed with beet

Fermentation characteristics of kwahaju (a typical Korean traditional alcoholic beverage) base were investigated during fermentation with different contents of nuruk (Korean-style bran koji) extract. The nuruk extract which was prepared by incubating the mixture of nuruk powder and water at 25℃ overnight and by filtering it was used to be 0.6%, 2.7%, 5% and 10% (v/v). Total and reducing sugar contents as well as acidity of the kwahaju base with 0.6% nuruk extract were higher than those with 2.7%, 5% and 10% at the fermentation end. Final pH values of all the base samples were ranged from 3.3 to 4.1. Alcohol concentrations of the base samples with 2.7%, 5% and 10% nuruk extract were higher than those with 0.6%. Microbial growth rate was great and inner temperature was high in the sample with high content of nuruk extract, but fermentation period was short. Total sugar consumption and alcohol production increased as the content of nuruk extract increased, but total acid production decreased. The base sample with 10% nuruk extract showed the most excellent fermentation efficiency. Fusel oil content of the base sample with 2.7% nuruk extract was the highest (457.3 ppm), and those wity 5% and 10% nuruk extract were 438.9 ppm and 442.6 ppm, respectively. The sample with 0.6% nuruk extract had the lowest content (409.5 ppm). Sensory evaluation of both the kwahaju base and kwahaju mix with 25% and 40% alcohol by adding soju (Korean distilled liquor) showed that the base with 2.7% nuruk extract had the highest score, and that the kwahaju mix with 25% alcohol had higher score than that with 40%. The sensory results on overall desirability were consistent to those on color and alcohol concentration, and it turned out that the two factors were important to make kwahaju.

Fermentation characteristics of Baikhaju (a typical Korean traditional alcoholic beverage) were investigated during fermentation with differently treated rice samples, which were steamed rice (SR), plain steamed rice bread (RB), rice porridge (RP) and roasted rice (RR). The RB sample showed an excellent fermentation efficiency with the highest alcohol production (20.84%). The SR and RR samples showed 17.79% and 17.31% of alcohol production, respectively. The RP sample was the lowest alcohol production (11.47%). The pH values of all the beverage samples were similar and were ranged from 3.6 to 3.9. The fermentation periods of RB and RR samples were longer than the SR and RP. The inner temperature and microbial growth in all the beverages increased at each of input steps of the rice and Nuruk (a Korean-style bran koji). Fusel oil content of the SR and RP samples (613.6 ppm) was higher than that of RR (482.7 ppm). The RB sample with the best fermentation efficiency had the lowest fusel oil content (341.8 ppm). The RP sample showed the highest score in sensory evaluation and RB sample showed the lowest. The results on sensory evaluation were contrary to those on the fermentation efficiency.

Fermentation characteristics and quality changes of the typical Korean traditional alcoholic beverages (Kwahaju, Sokokju, Baikhaju, Samhaeju and Hosanchun) were investigated during fermentation and after aging, respectively. They were prepared by their own brewing methods with respect to the same contents of rice and Nuruk (Korean-style bran koji). The consumed total sugar content of the alcoholic beverages (Sokokju, Baikhaju, Samhaeju and Hosanchun) which were brewed with the multiple input steps of seed mash and raw material (ABMIS) was higher than that of the alcoholic beverage (Kwahaju) which was brewed with the single input step (ABSIS). The pH values of all the beverages were similar and were ranged from 3.2 to 3.6. The acidity of ABMIS were lower than that of ABSIS, but alcohol concentration of ABMIS were higher. The fermentation period of the alcoholic beverages with triple input steps was the longest among them. The inner temperature and microbial growth in all the beverages increased at each of input steps of the raw materials. Fusel oil content of ABMIS was lower than that of ABSIS. Major components of the fusel oil were iso-amyl alcohol, iso-butanol, n-propanol, ethyl acetate and acetaldehyde, and its minor components were methanol and n-butanol. The results on quality changes of the alcoholic beverages after aging showed increase of alcohol in ABMIS, but decrease of sugar and acidity. Fusel oil contents of Kwahaju and Samhaeju decreased to be ranged from 3.1% to 13.9% after aging, but those of Sokokju, Baikhaju and Hosanchun increased to be ranged from 10.9% to 23.0%. Sensory evaluation of ABMIS showed better scores than that of ABSIS. It was suggested that the brewing method with multiple input steps of seed mash and raw material was one of the methods to increase fermentation efficiency for brewing the Korean traditional alcoholic beverages.

Physicochemical and sensory characteristics of Korean traditional alcoholic beverages, such as Kwahaju, Sokokju, Baikhaju, Samhaeju and Hosanchun were investigated during fermentation with the difference of input step and treatment of rice and Nuruk (Korean-style bran koji). pH values in all treatments were similar to be ranged 3.1~3.2, but acidity of the treatment brewed without seed mash was 1.5~2 times higher than that of the treatment brewed with seed mash. The concentration of alcohol in all treatments increased as the concentration of the Nuruk increased. The alcohol concentrations of Samhaeju and Hosanchun ranging from 6.5% to 7.7% were higher than those of Kwahaju, Sokokju and Baikhaju ranging from 7.9% to 10.6%. Residual reducing sugar contents of Kwahaju, Sokokju and Baikhaju ranging from 4.6 g/L to 9.7 g/L were lower than those of Samhaeju and Hosanchun ranging from 14.2 g/L to 15.5 g/L. The consumed total sugar contents of Kwahaju, Sokokju and Baikhaju ranging from 125.4 g/L to 159.2 g/L were higher than those of Samhaeju and Hosanchun ranging from 111.2 g/L to 123.8 g/L, and the treatments brewed with seed mash showed more sugar consumption than the treatments brewed without seed mash. Sensory quality in the treatments brewed with seed mash was better than those of without seed mash. Concentration of Nuruk and preparation of seed mash from it were critical factors compared to input step and treatment of rice in Korean traditional alcoholic beverage brewing.

지금까지 사용하지 못하고 버려왔던 엽삭액젓을 김치제조에 이용하게 할 목적으로 엽삭액젓의 주요 성분변화를 구명하기 위하여 수행한 본 연구의 결과를 요약하면 다음과 같다. 1. 숙성이 진행됨에 따라 일반성분중 조지방과 조단백질은 점차로 증가하는 추세를 보이다가 장기 숙성이 진행됨에 따라 감소하는 경향을 보였고, 수분은 감소하고, 회분과 염도는 증가하였다. 2. pH는 발효 20일째 6.4를 나타낸 이후로 뼈국물을 넣은 후인 32일째에는 6.6으로 약간 증가하고, 발효 35일째에 6.5로 약간 감소한 이후에는 거의 일정한 pH를 보였다. 총 산도는 발효 20일째에 1,174.6 mg%를 보였고, 뼈국물을 넣은 후인 32일째에 674.2 mg%로 크게 감소 하였다가 발효 35일째에 922.7 mg%로 증가한 이후에는 큰 변화를 보이지 않았다. 3. 어류의 신선도의 척도라 할 수 있는 휘발성염기질소의 변화는 발효 20일째에 63.7 mg%에서 계속적으로 증가하여 장기 숙성시킨 1년째에 224.8 mg%까지 증가하였다. 4. 단백질의 분해산물로서의 아미노태질소의 변화는 발효 20일째 352.5 mg%를 보였고 발효가 진행됨에 따라 계속 증가하여 장기 숙성시킨 1년째에 851.7 mg% 까지 증가하였다. 5. 지질의 산가의 변화는 발효초기인 20일째에 17.2를 보였고 발효가 진행됨에 따라 완만한 증가추세를 보여 발효 70일째에 28.5를 나타내고 120일째에 38.6까지 증가한 후 거의 변화를 보이지 않았다. 6. 지방산 조성에 있어서는 발효초기인 20일째에 포화지방산이 42.3%, 단일불포화지방산이 30.9%, 고도불포화지방산이 17.2%에서 숙성이 장기화됨에 따라 포화지방산은 증가하고 고도불포화지방산은 감소하여 숙성 1년째는 포화지방산은 46.2%, 단일불포화지방산은 28.3%, 고도불포화지방산은 14.7%를 나타내었다. 주요 지방산으로는 palmitic acid가 21% 이상으로 가장 많이 함유되어 있고 oleic acid, palmitoleic acid, myristic acid, eicosapentaenoic acid(EPA) 순으로 이들이 엽삭액젓 지방산의 70% 이상을 차지하였다. 7. 총 유리아미노산은 숙성이 진행됨에 따라 점차적으로 증가하는 경향을 보여서 발효초기인 20일째에 1158.2 mg%에서 장기 숙성시킨 1년째는 2651.5 mg%까지 증가하였다. 유리아미노산의 조성은 발효초기에는 arginine, glutamic acid, alanine, leucine valine이 주류를 이루었으나 숙성이 진행됨에 따라 glutamic acid, lysine, phenylalanine의 양이 증가하여 장기 숙성시킨 1년째는 glutamic acid, lysine, phenylalanine, arginine, alanine가 주된 아미노산임을 알 수 있었다.

발효시간을 0~10시간으로 달리한 증편 반죽에서 발효시간에 따른 이화학적 성질 변화를 검토하였다. 발효경과에 따라 pH는 감소하였으나 적정산도와 젖산은 계속적으로 증가하였다. 발효 중 총당은 계속적으로 감소하였으나 환원당은 발효초기 크게 증가하여 발효 4시간에 건물 기준으로 최대 101 mg/g에까지 도달한 다음 다시 감소하였다.

돌산갓의 독특한 향미와 잠재된 항균성을 김치의 맛과 저장성 향상에 이용하기 위한 기초자료로서 갓의 myrosinase를 분리 정제하여 그 특성을 밝히고, 갓김치 숙성 중 myrosinase 활성도 변화를 측정하였다. 갓의 myrosinase를 DEAE Sephadex, chromatofocusing 및 Con A Sepharose column chromatography에 의해 정제한 결과 비활성은 7107배 증가하였고 수율은 18.8%였다. 정제된 효소의 최적 pH는 5.9였으며, 등전점은 4.6, 분자량은 약 129 kD, Km은 0.206 mM, Vmax는 2.039 μM·min-1·mg protein-1로 나타났다. 또한 myrosinase의 activator인 ascorbic acid는 0.6 mM에서 최대 효소활성을 보이다가 그 이후는 점차 효소활성의 감소를 보여 2.0 mM 이상의 농도에서는 효소활성을 거의 완전히 상실시켰다. 갓김치의 저장 중 myrosinase 활성 변화를 측정한 결과 김치 제조 직후에 약 70 nmol/min/mg protein이던 것이 20℃에서 3일 이상 저장으로 급격히 그 활성을 잃어 4일 후에는 50% 이상의 활성을 손실하고 10일 후에는 거의 활성이 없었다.

본 연구는 새우젓(5%, 10%) 및 찹쌀풀(2.5%)의 첨가가 김치발효중 저급 질소화합물들의 함량변화에 미치는 영향을 살펴 본 것이다. 김치를 10℃에서 14일간 저장하면서 pH와 총산도, 유리당을 측정하여 김치의 발효정도를 조사하고, nitrite, dimethylamine(DMA)과 Volatile Basic Nitrogen(VBN) 함량을 정량하였다. 김치 발효초기의 아질산염 함량은 0.16-0.31 mg/kg의 수준을 보였으며, 그 중에서도 10% 새우젓 첨가시료들 (S2, GS2)이 비교적 높은 것으로 나타났다. 그러나 적숙기인 숙성 6일 이후에는 모든 시료들이 검출한계미만으로 흔적정도를 나타냈다. 발효가 진행되면서 시료중의 DMA 함량은 점차적으로 증가하였으며, 젓갈첨가량이 높을 수록 많이 검출되었다. 새우젓+찹쌀죽 첨가구(GS1, GS2)는 새우젓만 첨가한 시료들(S1, S2)보다 더 많이 검출되었다. 새우젓을 첨가한 시료들의 DMA 함량은 발효초기에 0.03-1.2 mg/kg이었으며, 발효말기에는 1.6-2.26 mg/kg이었다. VBN 함량은 발효가 진행되면서 점점 증가하여 새우젓 첨가구들(S1, S2) 또는 새우젓과 찹쌀풀을 첨가한 시료들(GS1, GS2)이 새우젓을 첨가하지 않은 시료들(C, G)보다 분명하게 높았으며, 새우젓 첨가구와 새우젓+찹쌀풀 첨가구는 유사한 양상을 보였으므로, 찹쌀풀을 첨가하는 것이 VBN 함량에 영향을 주지 않는 것으로 보인다.

This experiment was conducted to investigate the effects of propionic acid and wilting on fermentation quality of Italian ryegrass silage. Grass material was wilted for a day before ensiling and propionic acid(0. 0, 0. 2. 0. 5 and 0.8 7~ of fresh matter)

This experiment was conducted to enhance nutritional value of whole crop corn silage and increase mixture levels of broiler excreta by adding of corn meal. Treatments were included non mixture(control), adding 10, 20, 30% of broiler excreta and adding 10,

김치의 숙성과정 중의 물리적 특성을 측정하기 위하여 원료배추의 엽두께, 절임시의 두께 및 pH, total acidity, 염도 등의 변화를 연구하였다. 원료배추의 엽두께는 최외엽보다 내엽의 두께가 50% 감소되었고 절임의 경우에서는 외엽이 내엽보다 감소율이 낮았다. 배추조직의 절단력 측정에서는 절임으로 인하여 상대적인 절단력이 높았고 김치숙성이 되면서 증가하며 7일을 기준으로 감소하였다. Stress에서도 상대적 절단력과 같은 경향이나 숙성 후의 감소되는 점이 잘 나타나지 않았다. pH의 변화에 대한 상관식은 Y=0.23X+6.13이었고 젖산함량의 관계식은 Y=0.09X-0.01로서 매우 완만한 기울기이었으며 김치로서의 적정수준은 pH4.2, 젖산함량은 0.63의 수준이었고 기간은 7일이었다.

첨가 부재료를 달리한 김치를 18℃에서 24시간 예비 발효시킨 후, 4℃에서 35일간 저장하면서 질산염, 아질산염 및 vitamin C의 함량변화를 살펴보았다. 염도가 2.5% 수준인 김치 숙성도를 pH와 산도로 판정해 볼 때, 초기 숙성속도는 새우젓〉멸치, 갓, 마늘〉대조구, 무우〉ascorbic acid〉K-sorbate 순이었고 35일 후 pH 기준으로, 그 숙성도는 대조구〉갓〉무우〉ascorbic acid, 멸치젓〉새우젓〉K-sorbate〉마늘 첨가구 순이었다. 총 vitamin C 함량은 적숙기인 2주에 ascorbic acid 첨가구를 제외한 시료들에서 18.2-26.4 mg%로 담금직후와 같은 수준이었다. 그 중 환원형 ascorbic acid 보존율은 마늘, 갓, K-sorbate 첨가구에서 비교적 좋았다. 질산염, 아질산염의 함량은 숙성초기에 마늘, 무우첨가 김치에서 비교적 높았으며, 숙성기간 중 질산염의 함량범위는 260-490ppm이었고, 숙성 3주째에 최소량을 나타내었으며 이때 아질산염은 검출되지 않았다. 그리고, 총 vitamin C 함량도 이때 가장 낮았다.