• 멤브레인
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• 제14권1호
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• pp.44-52
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• 2004

본 연구는 직접메탄을 연료전지(Direct Methanol Fuel Cell)에 적용가능한 양이온교환막 개발에 관한 것으로 poly(vinyl alcohol) (PVA)에 가교제로 poly(acrylic acid-co-maleic acid) (PAM)와 hydroquinonesulfonic acid (HQSA)를 이용하여 가교제의 함량을 변화시키면서 막을 제조하였다. 제조한 막은 가교제의 함량 변화에 따라 메탄을 투과도, 이온전도도를 측정하였으며 기본적인 이온교환막의 특성인 함수율, 이온교환용량 그리고 고정이온농도 등을 측정하였다. PAM 함량이 증가함에 따라 메탄을 투과도와 이온전도도 및 함수율이 조금 증가하는 추세를 보이다 9 wt%부터 감소하는 경향을 보였는데 이는 PAM의 친수성기보다는 가교효과의 영향이라 사료되며 HQSA 함량을 변화시켰을 때는 이온전도도, 함수율 그리고 이온교환용량이 전반적으로 증가하였는데 그 증가폭은 미비하였다.

• 한국식품영양과학회지
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• 제41권4호
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• pp.539-549
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• 2012

본 연구는 오징어 가공식품개발의 기초자료확보를 위하여 산(acetic acid, 0~5%) 처리와 예비가열($55^{\circ}C$, $80^{\circ}C$) 후 열처리($100^{\circ}C$)에 따른 오징어의 이화학적 성분 변화를 조사하였다. 일반성분 함량은 수분이 약 73~78%, 조단백이 약 19~24%였으며 자숙 오징어의 일반성분 함량은 산 농도에 따라서 유의적인 차이가 있었다. 자숙 오징어의 모든 시료에서 주요 유리당은 ribose와 glucose이었으며, $55^{\circ}C$ 예비가열 시료는 다른 시료보다 glucose 함량이 낮은 것으로 나타났다. 총 유리당 함량은 표피 무제거 시료와 $80^{\circ}C$ 예비가열 시료순으로 높았고 $55^{\circ}C$ 예비가열 시료가 상대적으로 매우 낮았다. 모든 시료들의 유리아미노산 함량은 proline 함량이 가장 높았고 taurine, histidine 순으로 많이 함유되어 있었으며, 모든 자숙 오징어군에서 산 용액 처리농도에 따른 유의적인 영향을 보였다(p<0.05). 총 유리아미노산 함량은 $55^{\circ}C$ 예비가열 시료가 가장 높았고 $80^{\circ}C$ 예비가열, 표피 무제거 시료순으로 나타났다. 핵산관련물질은 모든 시료에서 inosine이 검출되지 않았고 ATP 함량이 가장 낮았다. $55^{\circ}C$와 $80^{\circ}C$ 예비가열 시료는 hypoxanthine 함량이 가장 높고 AMP와 IMP 함량이 비슷한 수치를 보였으나 표피 무제거 시료는 IMP 함량이 표피제거 시료보다 높았다. 지방산은 포화지방산이 약 40%로 palmitic acid 함량이 매우 높았고 불포화지방산은 약 60%로 EPA와 DHA 함량이 높았다. 지방산중 DHA 함량이 가장 높고 palmitic acid, EPA 순으로 나타났으며 이 세 가지가 총 지방산의 약 85%를 차지하고 있었다. 지방산은 산 처리와 가열 방법에 따른 뚜렷한 차이가 나타나지 않았다. 무기질의 함량은 인의 함량이 가장 높았고 칼륨, 나트륨, 마그네슘, 칼슘 순이었으며 예비가열 온도 또는 산 용액 농도에 따른 유의적인 영향을 받았다. 그리고 중금속류인 카드뮴, 납, 비소는 미량으로 나타나 식품 기준치보다 낮은 수준이었다.

• 농업과학연구
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• 제40권1호
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• pp.35-45
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• 2013

The fat content, fatty acid composition, trans fatty acid content and triacylglycerol (TAG) composition of 22 chocolates (domestics 8, foreigns 14) collected from the Korea distribution markets were investigated. The crude fat was extracted by acid hydrolysis method and analyzed by gas chromatography (GC) and reversed-phase HPLC for fatty acid and TAG compositions, respectively. The crude fat content of all chocolates varied between 30.11% and 49.59%. The major fatty acids in most of the chocolates were palmitic acid (19.36~31.15 wt%), stearic acid (5.11~36.32 wt%) and oleic acid (18.77~36.68 wt%). Whereas lauric acid (approximately 35.43 wt%) was detected in chocolate fat of sample No. 18. High oleic acid content was observed for the sn-2 position fatty acid with a range from 64.91% to 86.93%. Trans fatty acid contents in domestic chocolates (sample No. 1~8) and foreign chocolates (sample No. 9~22) were 0.03~0.59 wt% (0.01~0.19 g/100g chocolate) and 0.05~6.32 wt% (0.02~1.99 g/100g chocolate), respectively. In TAG composition, TAGs such as POP/PPO(1,3(2)-palmitoyl-2(3)-oleoyl glycerol, PN=48), POS/PSO(palmitoyl-oleoyl-stearoyl glycerol or palmitoyl-stearoyl-oleoyl glycerol, PN=50), SOS/SSO(1,3(2)-stearoyl-2(3)-oleoyl glycerol, PN=50) were mainly detected in most of the chocolates. The peaks of TAG with low PN (ex, 32-34, 36-38, and 40-42) were detected in No. 18 chocolate fat because of containing short chain fatty acid such as lauric acid.

• 한국식품영양학회지
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• 제11권4호
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• pp.437-443
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• 1998

This research is to establish the basic data of the nutritive value and improve our diet. In the part of the leaf and stem of the wild and cultivated horned rampion (Phyteuma japonicum Mig), the components such as chemical compositon, vitamin C, free sugar, mineral, nucleotide and its related compounds, composition and free amino acid were analyzed one after another. Content of the crude lipids and proteins was determined much higher in its wildness than in its cultivated horned rampion; while, that of carbohydrates was higher in the former than in the latter. The content of vitamin C was retained higher in the leaf than in the stem horned rampion. And the content of calcium among the detected minerals was outstanding in all of the samples collected, and potassium and magnesium was the next ones in its order. The main components of free sugars in both the wild and cultivated horned rampion were glucose and fructose, and their content was higher in the stem than in the leaf. Nucleotide and its related compounds were identified with 5 kinds of nucieotides such as CMP, UMP, IMP, AMP and hypoxanthine (Hx), and the content of Hx and AMP was the highest I the wild and cultivated samples, respectively. In the composition amino acid of the wild horned rampion, glutamic acid, aspartic acid and phenylalanine was outstandingly abundant; while, such amino acid as methinone and proline was small and besides cysteine couldn't be detected in the stem. Total amounts of composition amino acid in the leaf was 2118.0 and 1120.1mg% in the wild and cultivated sample, respectively. In the free amino acid of horned rampion, the total amount ranged from 8.5 to 50.1mg.%, which were lower level than that of composition amino acid. But the number of free amino acid was 29 kinds, which was bigger in its number than that of composition amino acid detected 17 kinds.

• 생물환경조절학회지
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• 제19권4호
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• pp.377-381
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• 2010

본 연구는 저장 기간 중 양파 구의 pyruvic acid와 당 함량의 변화를 분석하고자 한다. 저장 중의 pyruvic acid 함량은 저장 3개월까지는 큰 변화가 없었으나 저장 120일경부터 발근이 시작되면서 서서히 증가하기 시작하여 맹아기 이후 급격히 증가하였다. 그와 대조적으로 건물함량은 저장 기간 동안 큰 변화가 없었다. Sucrose 함량은 저장기간이 경과할수록 증가하다가 맹아가 진행됨에 따라 감소하였다. Fructose 함량은 저장 45일째 이후로 서서히 감소하여 맹아기 이후에는 큰 변화가 없었다. Glucose 함량은 저장기간이 경과할수록 증가하는 경향이었다. 저장기간 중 총당(TS) 함량에 대한 pyruvic acid(PA) 함량 비율(PA/TS ratio)은 수확시에 비해 저장 한 달 이후부터 감소하였으며, 이 후 내부맹아가 관찰되는 135일째부터 급격하게 증가하여 저장 150일에는 수확시에 비해 83% 정도 증가하였다. 저장기간 중 감미도는 저장 한 달 까지는 서서히 감소하였으나 그 이후 증가하였고, 저장기간 중 큰 변화가 없었다. 따라서 단 양파 선발은 휴면이 타파되기 전에 실시하는 것이 바람직할 것으로 생각된다.

• 한국자원식물학회지
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• 제30권6호
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• pp.590-600
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• 2017

A total of 447 accessions consisting of seven Brassica spp.; Brassica carinata (34), B. juncea (199), B. rapa subsp. dichotoma (18), B. rapa. subsp. oleifera (14), B. rapa subsp. rapa (36), B. rapa subsp. trilocularis (56) and B. alba subsp. alba (90) were studied for their morphological characters and fatty acid compositions. There was a wide variation for morphological traits, oil content and fatty acid composition among Brassica species. Seed number/silique and yield/plant were varied from 4.2 (B. alba) to 25.1 (B. rapa subsp. trilocularis) and from 170.7 g (B. rapa subsp. oleifera) to 351.9 g (B. juncea L. Czern.), respectively. Among Brassica species, B. rapa subsp. trilocularis exhibited the highest oil (29.2%), stearic (20.4%) and erucic acid (45.3%) content. B. carinata had the highest content of palmitic (5.2%), oleic (21.2%) and linolenic acid (11.1%). B. rapa subsp. dichotoma and B. rapa subsp. oleifera exhibited the highest content of linoleic (8.1%) and behenic (26.9%) acid, respectively. B. rapa subsp. trilocularis exhibited the highest (45.3%) erucic acid content and significant positive relationship was observed between oleic acid and linoleic acid. This variation of agronomic and fatty acid compositions in Brassica species can be utilized to develop new varieties.

• 한국식품과학회지
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• 제39권3호
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• pp.304-308
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• 2007

본 연구에서는 24시간 동안 싹튼 콩을 원료로 하여 콩알 메주를 제조한 후 발효기간에 따른 각종 품질의 변화를 조사하였다. 발효 전 기간 동안 pH는 6.3-6.5로 큰 변화가 없는 것으로 조사되었다. 증자 직후의 아미노태 질소함량은 15.5 mg%였으며, 발효가 진행됨에 따라 급격히 증가하여 발효 48시간째에는 312.9 mg%를 나타내었다. 발효기간별 미생물의 변화를 확인한 결과 곰팡이의 수가 높게 나타난 반면 호기성 세균과 효모의 수는 낮게 나타났는데 이는 메주의 제조 시 Aspergillus oryzae를 접종하였기 때문인 것으로 판단된다. 발효가 진행됨에 따라 유기산 함량은 점차 높아져 발효 48시간째에는 1,067.3 mg%가 검출되었으며 함량별로는 발효 전 기간에 걸처 citric acid가 가장 많이 검출되었다. 유리아미노산 함량은 발효가 진행됨에 따라 함량이 급격히 높아져 발효 48시간째에는 2,513.5 mg%로 발효 전에 비해 5.7배 가량 많이 검출되었다. 함량별로 보면 glutamic acid가 가장 많았으며, aspartic acid, lysine, leucine 및 proline의 순으로 많이 검출되었다. glutamic acid의 총아미노산에 대한 비율은 발효가 진행됨에 따라 점차 증가하여 발효 48시간째에는 21.2%로 나타났다. 총 Isoflavone의 함량은 발효초기에 123.9 mg%로 약간 증가한 후 그 수준을 지속적으로 유지하는 것으로 나타났으며, 발효 전 기간 동안 genistein>daidzein>glycitein의 순으로 나타났다.

• Animal Bioscience
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• 제34권10호
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• pp.1616-1622
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• 2021

Objective: Bioactive compounds in ruminant products are related to functional compounds in their diets. Therefore, this study aimed to explore the effect of forage sources, Italian ryegrass (IR) silage vs corn silage (CS) in the total mixed ration (TMR), on milk production, milk composition, and phytanic acid content in milk, as well as on the extent of conversion of dietary phytol to milk phytanic acid. Methods: Phytanic acid content in milk was investigated for cows fed a TMR containing either IR silage or CS using 17 cows over three periods of 21 days each. In periods 1 and 3, cows were fed CS-based TMR (30% CS), while in period 2, cows were fed IR silage-based TMR (20% IR silage and10% CS). Results: The results showed that there were no differences in fat, protein, lactose, solids-not-fat, somatic cell count, and fatty acid composition of milk among the three experimental periods. There were no differences in the plasma concentration of glucose, triglycerides, total cholesterol, and nonesterified fatty acids among the three experimental periods, while the blood urea nitrogen was higher (p<0.05) in period 2. The milk phytanic acid content was higher (p<0.05) in period 2 (13.9 mg/kg) compared with periods 1 (9.30 mg/kg) and 3 (8.80 mg/kg). Also, the phytanic acid content in the feces was higher (p<0.05) in period 2 (1.65 mg/kg dry matter [DM]) compared with period 1 (1.15 mg/kg DM), and 3 (1.17 mg/kg DM). Although the phytol contents in feces did not differ among the three feeding periods, the conversion ratio from dietary phytol to milk phytanic acid was estimated to be only 2.6%. Conclusion: Phytanic acid content in cow's milk increases with increasing phytol content in diets. However, phytol might not be completely metabolized in the rumen and phytanic acid, in turn, might not be completely recovered into cow's milk. The change of phytanic acid content in milk may be positively correlated with the change of phytol in the diet within a short time.

• 한국초지조사료학회지
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• 제11권1호
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• pp.53-59
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• 1991

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) was applicated at ensiling time. Chemical composition, fermentation acids, pH, microbial population and distribution of the nitrogen contents were evaluated. The results obtained are summarized as follows: 1. The contents of dry matter and water soluble carbohydrate in the silage were increased by wilting, and crude fibre, NDF and ADF were decreased with increasing propionic acid levels. 2. The pH values of the silage increased by increasing DM content, but decreased with increasing propionic acid levels. Lactic acid content lowed in wilted silage, and acetic acid and butyric acid formation were decreased with increasing propionic acid levels. 3. Total nitrogen content in the silage was i n ~ r e a s e d ( ~ < . 05) by addition of propionic acid and wilting, and was the highest in the prewilting-0.8 Q propionic acid applicated silage. The production of NHBN was decreased with propionic acid and was the lowest in the 0.8 % treated silage. 4. The number of total bacteria and yeasts were estimated $10^6~10^7$, $10^2~10^3$ respectively. Moulds number were decreased with increasing propionic acid levels.

• 한국식품영양과학회지
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• 제23권5호
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• pp.792-798
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• 1994

In order to investigate the antioxidant activity of phenolic compounds contained in domestic Meju and Doenjang , the methanolic extract from defatted Meju and Doenjang was fractionated into the phenolic acid and the isoflavone fractions by alumina column and polyamide-6 column chromatography, respectively. Both phenolic acid and isoflavone fractions exhibited an identical antioxidative effect against the oxidation of linoleic acid. GC analysis revealed that the phenolic acid fractio contained vanillic , chlorogenic ,p-coumalic , ferulic, and caffeine acid. The content of caffic acid was greater than 70% in the phenolic acid fraction and the content of vanillic and chlorogenic acids were disappeared during fermentation, and thus, the facts are thought to be reasons for the low antioxidant activity of the phenolic aicd fraction from Doenjang. Similarly, the isoflavone fraction cotained daidzin, glycitin-65-0 glucosider and genistin and their aglycons such as daidzein, glyciten and genistein. The content of daidzin and genistin in Meju dramatically decreased at the early stage of fermentation ,whereas the content of daidzein an dgenistein rather increased ; however, these change in isoflavone contents did not affect the antioxidant activity of isoflavone fractions.