• Title/Summary/Keyword: flavor change

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Quality Characteristic of Wheat Doenjang according to Mixing Ratio of Meju (메주의 배합비를 달리한 밀된장의 품질특성)

  • Lee, Gyeong-Ran;Ko, Yu-Jin;Kim, Eun-Ja;Kim, Il-Hun;Shim, Ki-Hwan;Kim, Young-Gi;Ryu, Chung-Ho
    • Food Science and Preservation
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    • v.20 no.2
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    • pp.191-198
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    • 2013
  • In this study, wheat doenjang was manufactured using Korean wheat meju and soybean meju, and its quality were investigated according to mixing ratio of meju. The general characteristics such as moisture contents, pH and salinity of wheat doenjang, which is fermented and aged at $25^{\circ}C$ for 70 days, were slightly decreased time dependently as similar pattern. The pH of wheat doenjang ranged from 4.95 to 5.11% and generally decreased with aging. The moisture contents was 54.5~57.5%, and there was no significant differences in the aging period. Also, there was no significant changes in the salt contents. The amino-type nitrogen contents were 376.27~600.91 mg% at day 70 of the aging period, and showed 3 fold change compared to the initial contents. The reducing sugar contents showed significant difference between the samples, and repeated fluctuation in the aging period. Wheat meju sample A, which contains 50% of soybean meju, showed the highest antioxidation ability. In addition, wheat meju sample A showed the highest score in the sensory evaluation of the colour, taste, flavor, and overall acceptability. Therefore, wheat doenjang manufacturing at a 1:1 of mixing ratio will lead to desirable quality of wheat doenjang.

A Study on Flavorous Taste Components in Kimchis -On Free Amino Acids- (김치의 맛 성분(成分)에 관(關)한 연구(硏究) -유리(遊離) 아미노산(酸)에 관(關)하여 -)

  • Cho, Young;Rhee, Hai-Soo
    • Korean Journal of Food Science and Technology
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    • v.11 no.1
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    • pp.26-31
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    • 1979
  • Free amino acids and total free sugar of kimchi were identified. Free amino acids of kimchis were extracted by 80% ethanol and isolated by ion exchange chromatography. Identification and quantitative determination of individual free amino acids were performed by amino acid autoanalyzer. Free sugar of kimchis was extracted by aqueous ethanol and isolated by ion exchange chromatography. Quantitative determination of it was perfermed by spectrophotometer. The results are summarized as follows: 1. Lysine, histidine, arginine, tryptophan, aspartic acid, threonine, glutamic acid, proline, glycine, alanine, cysteine, valine, methionine, leucine, isoleucine, tyrosine and phenylalanine were found in all kimchis. 2. The change of free amino acid composition during fermentation of kimchis was not observed, but the amount of total free amino acids of fermented kimchi decreased as compared with those of raw kimchi. 3. In kimchi containing 10 ml of fermented anchovy solution/100 g of chinese cabbage, the amount of total free amino acids was more than that of fermented salt kimchi and the characteristic flavor of it was attributed to such amino acids as lysine, aspartic acid, glutamic acid, valine, methionine, isoleucine and leucine. 4. Large amount of free sugar in raw salt kimchi decreased during fermentation, but, after fermentation, significant difference of free sugar content between salt kimchi and kimchi containing fermented anchovy solution was not observed.

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Change of Fragrant Components by Flowering Stages in Lilium Oriental Hybrid 'Casa Blanca' (오리엔탈 나리 '카사블랑카'의 개화단계별 향기성분 변화)

  • Rho, A Ran;Pak, Chun Ho
    • Horticultural Science & Technology
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    • v.19 no.2
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    • pp.163-169
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    • 2001
  • This experiment was conducted to find out suitable extraction time of available fragrant component in Lilium Oriental Hybrida 'Casa Blanca' based on qualitative and quantitative variation of its fragrant component in its flowering stages. The content of essential oil in its flowering stages increased with the progress of flowering stages except flower bud stage and it had the most oil content in its stage after full bloom. The analysis of the essential oil in Lilium Oriental Hybrida 'Casa Blanca' in its flowering stages shows that its main constituents were farnesol (18.96%), benzyl salicylate (13.81%), butyl-hydroxy toluene (12.87%), geranyl linalool isomer (7.46%), isoeugenol (7.17%) in its each stage. Benzenoids had much content at half bloom stage and full bloom stage while fatty acid derivatives had much content at initial flowering stage and after flowering stage. Most benzenoids such as butyl-hydroxy toluene and isoeugenol, which are some of main constituents of Lilium Oriental Hybrida 'Casa Blanca' had strong antioxidant effect. So they were expected to be used as antioxidant agents for food, feed, vegetable oil. The content of monoterpene compounds like geranyl linalool isomer increased at its later stage. Sesquiterpene such as farnesol, which is main component of lily existed only at full bloom stage. Therefore farnesol and geranyl linalool isomer of Lilium Oriental Hybrida 'Casa Blanca' are expected to be used for important spices with good fragrance. The suitable extraction time for the usable main constituents of Lilium Oriental Hybrida 'Casa Blanca' is as follows; farnesol and benzyl salicylate: at full bloom stage, butyl-hydroxy toluene: at half bloom stage, geranyl linalool isomer and isoeugenol: at stage after full bloom. Finally there was variation in essential oil components and contents of Lilium Oriental Hybrida 'Casa Blanca' in its flowering stages and they are expected to be used usefully for flavor industry, food industry, aromatherapy, when they are extracted at their suitable extraction time.

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Determination of Shelf-life of Black Mini Tomato Based on Maturity and Storage Temperature (흑색 방울토마토의 숙기 및 저장온도에 따른 상품성 유지기간 구명)

  • Park, Mehea;Seo, Jeongmin;Won, Heeyeon;Seo, Jongbun;Moon, Doogyung;Kim, Wooil;Shim, Sangyoun
    • Horticultural Science & Technology
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    • v.33 no.5
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    • pp.687-696
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    • 2015
  • Black mini tomato 'Hei-G' fruits were harvested at different stages of maturity (immature-mature green and mature-black red) and stored at different temperatures (8, 12, and $20^{\circ}C$) to investigate the quality and lycopene content during storage. Weight loss increased dramatically at higher temperature for both harvesting stages without significant differences. Firmness of immature fruits decreased below the initial level of mature fruit (8.1N) after 5, 8, and 19 days storage, when they were stored at 20, 12, and $8^{\circ}C$, respectively. Soluble solid contents of mature fruit increased at initial storage, and were higher as compared to immature fruits before deterioration at each storage temperature. Decrease in titratable acid of mature fruits depended on storage time and temperature. However, titratable acid of immature fruits showed little change during storage, and so it did not affect flavor. Hunter a value changed greatly in immature fruit stored at high temperature. Unlike ripe tomatoes, there was no significant difference in black tomato Hunter b values of immature and mature fruit at initial and 12 days storage. However, immature fruits stored at $8^{\circ}C$ did not reach full maturity and color development and ripening. High storage temperature increased lycopene production while low storage temperature blocked lycopene development. Shelf life of the immature fruits, which was evaluated by elapsed days to conventional mature stage, was 12 and 15 days when they were stored at 20 and $12^{\circ}C$, respectively. The optimum storage temperature to maintain the quality and lycopene content of mature fruits was $12^{\circ}C$. Moreover, the shelf life of mature fruits stored at $20^{\circ}C$ could reach up to 5 days.

Quality Characteristics of Brown Rice Vinegar by Ferment Ratio (발효제 비율에 따른 현미식초의 품질특성)

  • Baek, Chang-Ho;Choi, Ji-Ho;Choi, Han-Seok;Jeong, Seok-Tae;Lee, Su-Won;Kwon, Joong-Ho;Woo, Seung-Mi;Jeong, Yong-Jin;Yeo, Soo-Hwan
    • Food Science and Preservation
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    • v.18 no.6
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    • pp.875-883
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    • 2011
  • Brown rice vinegar was made from brown rice mash with different brewing starter addition rates in static culture, and its quality characteristics were investigated. As a result, the amounts of alcohol produced in the fermentation process were shown to be 9.1, 8.8, 8.6 and 8.5% in the Nuruk 75 : crude enzyme 25 (B), Nuruk 50 : crude enzyme 50 (C), Nuruk 25 : crude enzyme 75 (D) and Nuruk 0 : crude enzyme 100 (E), respectively. The higher the percentage of crude enzyme added was, the lower the alcohol content that was produced. Nuruk 100 : crude enzyme 0 (A) was appeared to contain the lowest alcohol content (7.7%). In addition, the titratable acidity in all the groups was about 0.7%. The final titratable acidity (BV) of brown rice vinegar made with static culture was the highest (approximately 5.2%). The initial pH appeared to be between 3.6~4.0 and steadily decreased as the fermentation progressed, and the pH was almost unchanged after 15 day fermentation. The examination of the changes in the organic acids showed that the acetic acid content was similar in all the groups, and that the single starter added (AV, EV) group had much more other organic acids than the mixed starters added (BV, CV, DV) group. From these results, the mixed starters (Nuruk and crude enzyme) added group appeared to be superior to the single starter added in terms of alcohol production ability and vinegar quality. As the future aging process, however, is expected to change the flavor components and sensory characteristics, studies on various quality factors of vinegar are needed.

Quality Characteristics and Shelf-life of Tofu Coagulated by Furie Juice of Pomegranate (석류 농축액 첨가 두부의 품질특성 및 저장성)

  • Kim, Ji-Young;Park, Geum-Soon
    • Journal of the Korean Society of Food Culture
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    • v.21 no.6
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    • pp.644-652
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    • 2006
  • This study was investigated the utilization of pomegranate(P) as coagulants for 새려 manufacture, the quality characteristics and shelf-life on tofu made by P1(fruit juice of pomegranate 1%) and P2(fruit juice of pomegranate 2%) and P3(fruit juice of pomegranate 3%) and P4(fruit juice of pomegranate 4%) and P5(fruit juice of pomegranate 5%) were investigated and compared to G.D.L(C). And also, total microbe and tatal acid of the tofu were determined during storage at $0^{\circ}C^$. The results are summarized as follow P3(493.3g/500ml) compared to C(485g/500ml) showed the highest yield. Turbidity of tofu was increased as the proportion of pomegranate was increased, while pH of tofu was increased as the proportion of pomegranate was decreased. $L^{\ast}^{\ast}^{\ast}$ value of C tofu was highest, $a^{\ast}^{\ast}^{\ast}$ value of tofu was increased as the proportion of pomegranate was increased and $b^{\ast}^{\ast}^{\ast}$ value of C tofu was higher than those of other tofus. The hardness of tofu coagulated with pomegranate showed higher than that of coagulated G.D.L. The cohesiveness of P4, P5 showed higher than C tofu, but those of other tofus showed lower than C tofu. The springiness of tofu showed in the order of P4>P5>P3>P2>P1, gumminess of P5 tofu was highest. The Brittleness of tofu was increased as the proportion of pomegranate increased. The pH value of tofu coagulated with pomegranate increased during storage at $0^{\circ}C^$. During the storage period of tofu, pH and total acid showed a maximum change in C tofu. Generally the total plate counts of bacteria of all tofu increased during storage at $0^{\circ}C^$, and those of tofu with added pomegranate were shown to be lower than C tofu. The results of S.E.M(scanning electron microscopes), the lower hardness showed the more soft and the smaller particle, The particle of C tofu was small and uniformity but the size of P4, P5 tofu showed coarse. In the sensory evaluation of all tofu, sleekness, nutty, chewiness and smoothness, appearance and overall quality was the highest in C tofu. In the sensory evaluation of tofus coagulated with pomegranate. overall quality was the highest in P2.

Quality improvement and aging effect of beef by low-temperature treatment of non-preferred parts of beef (비선호 부위 소고기의 저온처리에 의한 품질향상 및 소고기의 숙성효과)

  • Hyun Kyoung Kim;Soon Cheol Kim;Hyeon Jin Kim;Yeong Mi Kim
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.5
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    • pp.753-760
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    • 2023
  • In this study, quality improvement of beef was attempted according to the low temperature treatment and aging period of grade 1 compared to grade 1++ beef. The fat content and shear force of beef grade 1++ were 13.03% and 114.26N, but beef grade 1 was 3.21% and 149.67N. Meanwhile, after low-temperature treatment of grade 1 beef at -26℃ for 12 hours and low-temperature aging at 0 ℃ for 14 days, the shear force was greatly reduced to 87.85N, improving overall preference, softness, dripping gravy, flavor, and chewing texture. The essential free amino acid content was as low as 22.17mg/100g in grade 1++ beef, but the contents were high at 41.31~45.11mg/100g in three samples of grade 1, and there was no change in content according to cold treatment conditions. As a specific component of beef, Taurine was 30.94~34.41mg/100g, and the difference in content was small according to beef grade, but Anserine and Creatine were low at 19.68mg/100g and 70.01mg/100g in beef grade 1++ and high at 26.38~31.23mg/100g and 154.09~167.26mg/10g in beef grade 1. The content ratio of oleic acid (c18:1)/stearic acid (c18:0) as an monounsaturated fatty acid/saturated fatty acid ratio was low at 5.29 for grade 1++ beef, but high at 6.13~6.78 for grade 1 beef. In addition, there was no trend in the content ratio of these fatty acids according to the low-temperature treatment conditions and aging period in beef grade 1. As a result of this study, it was possible to improve the quality of beef grade 1 by low-temperature treatment at -26 ℃ for 12 hours and then aging at 0 ℃ for 14 days.

Microbiological and Enzymological Studies on Takju Brewing (탁주(濁酒) 양조(釀造)에 관(關)한 미생물학적(微生物學的) 및 효소학적(酵素學的) 연구(硏究))

  • Kim, Chan-Jo
    • Applied Biological Chemistry
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    • v.10
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    • pp.69-100
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    • 1968
  • 1. In order to investigate on the microflora and enzyme activity of mold wheat 'Nuruk' , the major source of microorganisms for the brewing of Takju (a Korean Sake), two samples of Nuruk, one prepared at the College of Agriculture, Chung Nam University (S) and the other perchased at a market (T), were taken for the study. The molds, aerobic bacteria, lactic acid bacteria, and yeasts were examined and counted. The yeasts were classified by the treatment with TTC (2, 3, 5 triphenyltetrazolium chloride) agar that yields a varied shade of color. The amylase and protease activities of Nuruk were measured. The results were as the followings. a) In the Nuruk S found were: Aspergillus oryzae group, $204{\times}10^5$; Black Aspergilli, $163{\times}10^5$; Rhizogus, $20{\times}10^5$; Penicillia, $134{\times}10^5$; Areobic bacteria, $9{\times}10^6-2{\times}10^7$; Lactic acid bacteria, $3{\times}10^4$ In the Nuruk T found were: Aspergillus oryzae group, $836{\times}10^5$; Black Aspergilli, $286{\times}10^5$; Rhizopus, $623{\times}10^5$; Penicillia, $264{\times}10^5$; Aerobic bacteria, $5{\times}10^6-9{\times}10^6$; Lactic acid bacteria, $3{\times}10^4$ b) Eighty to ninety percent of the aerobic bacteria in Nuruk S appeared to belong to Bacillus subtilis while about 70% of those in Nuruk T seemed to be spherical bacteria. In both Nuruks about 80% of lactic acid bacteria were observed as spherical ones. c) The population of yeasts in 1g. of Nuruk S was about $6{\times}10^5$, 56.5% of which were TTC pink yeasts, 16% of which were TTC red pink yeasts, 8% of which were TTC red yeasts, 19.5% of which were TTC white yeasts. In Nuruk T(1g) the number of yeasts accounted for $14{\times}10^4$ and constituted of 42% TTC pink. 21% TTC red pink 28% TTC red and 9% TTC white. d) The enzyme activity of 1g Nuruk S was: Liquefying type Amylase, $D^{40}/_{30},=256$ W.V. Saccharifying type Amylase, 43.32 A.U. Acid protease, 181 C.F.U. Alkaline protease, 240C.F.U. The enzyme activity of 1g Nuruk T was: Liquefying type Amylase $D^{40}/_{30},=32$ W.V. Saccharifying type amylase $^{30}34.92$ A.U. Acid protease, 138 C.F.U. Alkaline protease 31 C.F.U. 2. During the fermentation of 'Takju' employing the Nuruks S and T the microflora and enzyme activity throughout the brewing were observed in 12 hour intervals. TTC pink and red yeasts considered to be the major yeasts were isolated and cultured. The strains ($1{\times}10^6/ml$) were added to the mashes S and T in which pH was adjusted to 4.2 and the change of microflora was examined during the fermentation. The results were: a) The molds disappeared from each sample plot since 2 to 3 days after mashing while the population of aerobic bacteria was found to be $10{\times}10^7-35{\times}10^7/ml$ inS plots and $8.2{\times}10^7-12{\times}10^7$ in plots. Among them the coccus propagated substantially until some 30 hours elasped in the S and T plots treated with lactic acid but decreased abruptly thereafter. In the plots of SP. SR. TP. and TR the coccus had not appeared from the beginning while the bacillus showed up and down changes in number and diminished by 1/5-1/10 the original at the end stage. b) The lactic acid bacteria observed in the S plot were about $7.4{\times}10^7$ in number per ml of the mash in 24 hours and increased up to around $2{\times}10^8$ until 3-4 days since. After this period the population decreased rapidly and reached about $4{\times}10^5$ at the end, In the plot T the lactic acid becteria found were about $3{\times}10^8$ at the period of 24 fours, about $3{\times}10$ in 3 days and about $2{\times}10^5$ at the end in number. In the plots SP. SR. TP, and TR the lactic acid bacteria observed were as less as $4{\times}10^5$ at the stage of 24 hours and after this period the organisms either remained unchanged in population or ceased to exist. c) The maiority of lactic acid bacteria found in each mash were spherical and the change in number displayed a tendency in accordance with the amount of lactic acid and alcohol produced in the mash. d) The yeasts had showed a marked propagation since the period of 24 hours when the number was about $2{\times}10^8$ ㎖ mash in the plot S. $4{\times}10^8$ in 48 hours and $5-7{\times}10^8$ in the end period were observed. In the plot T the number was $4{\times}10^8$ in 24 hours and thereafter changed up and down maintaining $2-5{\times}10^8$ in the range. e) Over 90% of the yeasts found in the mashes of S and T plots were TTC pink type while both TTC red pink and TTC red types held range of $2{\times}10-3{\times}10^7$ throughout the entire fermentation. f) The population of TTC pink yeasts in the plot SP was as $5{\times}10^8$ much as that is, twice of that of S plot at the period of 24 hours. The predominance in number continued until the middle and later stages but the order of number became about the same at the end. g) Total number of the yeasts observed in the plot SR showed little difference from that of the plot SP. The TTC red yeasts added appeared considerably in the early stage but days after the change in number was about the same as that of the plot S. In the plot TR the population of TTC red yeasts was predominant over the T plot in the early stage which there was no difference between two plots there after. For this reason even in the plot w hers TTC red yeasts were added TTC pink yeasts were predominant. TTC red yeasts observed in the present experiment showed continuing growth until the later stage but the rate was low. h) In the plot TP TTC pink yeasts were found to be about $5{\times}10^8$ in number at the period of 2 days and inclined to decrease thereafter. Compared with the plot T the number of TTC pink yeasts in the plot TP was predominant until the middle stage but became at the later stage. i) The productivity of alcohol in the mash was measured. The plot where TTC pink yeasts were added showed somewhat better yield in the earely stage but at and after the middle stage the difference between the yeast-added and the intact mashes was not recognizable. And the production of alcohol was not proportional to the total number of yeasts present. j) Activity of the liquefying amylase was the highest until 12 hours after mashing, somewhat lowered once after that, and again increased around 36-48 hours after mashing. Then the activity had decreased continuously. Activity of saccharifying amylase also decreased at the period of 24 hours and then increased until 48 hours when it reached the maximum. Since, the activity had gradually decreased until 72 hours and rapidly so did thereafter. k) Activity of alkaline protease during the fermentation of mash showed a tendency to decrease continusously although somewhat irregular. Activity of acid protease increased until hours at the maximum, then decreased rapidly, and again increased, the vigor of acid protease showed better shape than that of alkaline protease throughout. 3. TTC pink yeasts that were predominant in number, two strains of TTC red pink yeasts that appeared throughout the brewing, and TTC red yeasts were identified and the physiological characters examined. The results were as described below. a) TTC pinkyeasts (B-50P) and two strains of TTC red pink yeasts (B-54 RP & B-60 RP) w ere identified as the type of Saccharomyces cerevisiae and TTC pink red yeasts CB-53 R) were as the type of Hansenula subpelliculosa. b) The fermentability of four strains above mentioned were measured as follows. Two strains of TTC red pink yeasts were the highest, TTC pink yeasts were the lowest in the fermantability. The former three strains were active in the early stage of fermentation and found to be suitable for manufacturing 'Takju' TTC red yeasts were found to play an important role in Takju brewing due to its strong ability to produce esters although its fermentability was low. c) The tolerance against nitrous acid of strains of yeast was marked. That against lactic acid was only 3% in Koji extract, and TTC red yeasts showed somewhat stronger resistance. The tolerance against alcohol of TTC pink and red pink yeasts in the Hayduck solution was 7% while that in the malt extract was 13%. However, that of TTC red yeasts was much weaker than others. Liguefying activity of gelatin by those four strains of yeast was not recognized even in 40 days. 4. Fermentability during Takju brewing was shown in the first two days as much as 70-80% of total fermentation and around 90% of fermentation proceeded in 3-4 days. The main fermentation appeared to be completed during :his period. Productivity of alcohol during Takju brewing was found to be apporximately 65% of the total amount of starch put in mashing. 5. The reason that Saccharomyces coreanuss found be Saito in the mash of Takju was not detected in the present experiment is considered due to the facts that Aspergillus oryzae has been inoculated in the mold wheat (Nuruk) since around 1930 and also that Koji has been used in Takju brewing, consequently causing they complete change in microflora in the Takju brewing. This consideration will be supported by the fact that the original flavor and taste have now been remarkably changed.

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Studies on Takju Brewing with Potatoes (감자를 이용(利用)한 탁주제조(濁酒製造)에 관(關)한 연구(硏究))

  • Kim, S.Y.;Oh, M.J.;Kim, C.J.
    • Applied Biological Chemistry
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    • v.17 no.2
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    • pp.81-92
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    • 1974
  • In order to prepare the mashing materials for 'Takju', Korean wine, with potatoes, theywere steamed, dryed, and pulverized, and their chemical components were analyzed. As a brewing method of Takju with potatoes, general 2nd stage process with Ipkuk and Bunkuk (enzyme sources), commonly used now, was carried out and the effects of preparing conditions of Ipkuk(koji) with potato flour, mashing materials and brewing conditions on the contents of Takju mash, and of storing time on the contents of Takju, were investigated and the results obtained were summarized as follows, 1. Chemical components of steamed potatoes and potato flour were Moisture; 76.2, 10.8%, Total sugar; 16.1, 69.8%, Reducing sugar; 3.45, 13.4%, Crude protein; 2.1, 11.3%, Total acid; 0.012, 0.023% and Volatile acid; 0.0012, 0.0025% respectively. 2. The most effective preparing conditions of Ipkuk with potato flour were to incubate the potato flour added 40-50% of water for 48 hours by general preparing process of Koji, and liquefying and saccharogenic amylase activities of Ipkuk incubated at above conditions were $D40^{\circ}$ 30' 128 W.V. and 13.2 A.U.. 3. The effects of various brewing conditions on the contents of Takju mashes were as follows; 1) Optimum ratio of mashing water and materials for Takju brewing with potato flour was 140ml of water to 60g of flour in 1st stage and 260ml to 140g in 2nd stage. 2) Optimum fermentating times and temperatures for Takju brewing were at $25^{\circ}C$ for 48 hours in 1st stage and at $30^{\circ}C$ for 48 hours in 2nd stage. 3) Optimum amounts of enzyme sources for Takju brewing were 20-30% of Ipkuk and 0.5% of Bunkuk in 1st stage and 1.0% of Bunkuk in 2nd stage. 4) Methanol content of the Takju mash brewed with raw potato flour was much more than that with steamed potato flour. 5) Alcohol, fusel oil and Formol nitrogen contents of the Takju mash brewed with potato flour were less than that with wheat flour, on the contrary, methanol contents and total acidifies of them were showed conversely above. 4. The changes of chemical components and microflora in the mashes during the brewing potato flour Takju were as follows; 1) The accumulation of ethanol followed rapidly in early stage, being the highest at 72 hours (11.9%). 2) Total sugar content of the mash was decreased considerably within 48-72 hours, being 2.62% at 72 hours, and thereafter slowly. 3) Reducing sugar of the mash had a tendency of decreasing, being 0.29% at 48 hours. 4) Total acidity, volatile acidity and Formol nitrogen content of the mash were increased slowly, being 7.30, 0.20, 2.55 at 48 hours. 5) Total cells of yeast appeared the highest in 72 hours ($2.1{\times}10^8$) and thereafter decreased slowly. 6) Total cells of bacteria appeared the highest in 48 hours ($2.4{\times}10^8$) and thereafter decreased or increased slightly. 5. Takju was made from the fermented mash mixed with water to be 6% of alcohol content, and the change of alcohol content, total acidity, total cells of yeast and bacteria during the storing at $30^{\circ}C$ were as follows; 1) Alcohol content of Takju was increased slightly at 24 hours (6.2%), and thereafter decreased slowly. 2) Total acidity of Takju was increased gradually, being 6.1 at 72 hours 3) Total cells of yeast and bacteria appeared the highest at 48 hours ($2.3{\times}10^8,\;1.5{\times}10^8$), and thereafter decreased slowly. 6. Alcohol content, total acidity and Formol nitrogen content of the Takju brewed with potato flour Ipkuk or wheat flour Ipkuk and steamed potatoes(1:5) were 9.8-11.3%, 5.8-7.4, 2.5-3.3 respectively, and the color of the Takju. was similar to commercial Takju. 7. The results of sensory test for various experimental Takju, showed that the Takjues brewed with the materials combined with wheat flour and steamed potatoes(4:5 or 3.5:7.5) were not significantly different in color, taste and flavor from commercial Takju, However, those with potato flour and wheat flour (1:1 or 7:3) were significantly different from commercial Takju.

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Studies on Takju Brewing with Potatoes (감자를 이용(利用)한 탁주제조(濁酒製造)에 관(關)한 연구(硏究))

  • Kim, S.Y.;Oh, M.J.;Kim, C.J.
    • Korean Journal of Agricultural Science
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    • v.1 no.1
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    • pp.67-81
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    • 1974
  • In order to prepare the mashing materials for "Takju", Korean wine, with potatoes they were steamed, dryed, and pulverized, and their chemical components were analyzed. As a brewing method of Takju with potatoes, general 2nd stage process with Ipkuk and Bunkuk (enzyme sources), commonly used now, was carried out and the effects of preparing conditions of Ipkuk(koji) with potato flour, mashing materials and brewing conditions on the contents of Takju mash and of storing time on the contents of Takju, were investigated and the results obtained were summarized as follows. 1. Chemical components of steamed potatoes and potato flour were Moisture; 76.2, 10.8%, Total sugar; 16.1, 69.8%, Reducing sugar; 3.45, 13.4%, Crude protein; 2.1, 11.3%, Total acid; 0.012, 0.023% and Volatile acid; 0.0012, 0.0025% respectively 2. The most effective preparing conditions of Ipkuk with potato flour were to incubate the potato flour added 40-50% of water for 48 hours by general preparing process of Koji, and liquefying and saccharogenic amylase activities of Ipkuk incubated at above conditions were $D_{40^{\circ}}{^{30{\prime}}}$ 128 W.V. and 13.2 A. U. 3. The effects of various brewing conditions on the contents of Takju mashes wereas follows; 1) Optimum ratio of mashing water and materials for Takju brewing with potato flour was 140ml of water to 60g of flour in 1st stage and 260ml to 140g in 2nd stage. 2) Optimum fermentating times and temperatures for Takju brewing were at $25^{\circ}C$ for 48 hours in 1st stage and at $30^{\circ}C$ for 48 hours in 2nd stage. 3) Optimum amounts of enzyme sources for Takju brewing 20-30% of Ipkuk and 0.5% of Bunkuk in 1st stage and 1.0% of Bunkuk in 2nd stage. 4) Methanol content of the Takju mash brewed with raw potato flour was much more than that with steamed potato flour. 5) Alcohol fusel oil and Formal nitrogen contents of the Takju mash brewed with potato flour were less than that with wheat flour, on the contrary, methanol contents and total acidities of them were showed conversely above. 4. The changes of chemical components and microflora in the mashes during the brewing potato flour Takju were as follows; 1) The accumulation of ethanol followed rapidly in early stage, being the highest at 72 hours (11.9%) 2) Total sugar content of the mash was decreased considerably within 48-72 hours, being 2.62% at 72 hours, and thereafter slowly. 3) Reducing sugar of the mash had a tendency of decreasing, being 0.29% at 48 hours. 4) Total acidity, volatile acidity and Formal nitrogen content of the mash were increased slowly, being 7.30, 0.20, 2.55 at 48 hours. 5) Total cells of yeast appeared the highest in 72 hours ($2.1{\times}10^8$) and thereafter decreased slowly. 6) Total cells of bacteria appeared the highest in 48 hours ($2.4{\times}10^8$) and thereafter decreased or increased slightly. 5. Takju was made from the fermented mash mixed with water to be 6% of alcohol content, and the change of alcohol content, total acidity, total cells of yeast and bateria during the storing at $30^{\circ}C$ were as follows; 1) Alcohol content of Takju was increased slightly at 24 hours (6.2%), and thereafter decreased slowly. 2) Total acidity of Takju was increased gradually, being 6.1 at 72 hours 3) Total cells of yeast and bacteria appeared the highest at 48 hours ($2.3{\times}10^8$, $1.5{\times}10^8$) and thereafter decreased slowly. 6. Alcohol content, total acidity and Formol nitrogen content of the Takju brewed with potato flour Ipkuk or wheat flour Ipkuk and steamed potatoes(1:5) were 9.8-11.3%, 5.8-7.4, 2.5-3.3 respectively, and the color of the Takju was similar to commercial Takju. 7. The results of sensory test for various experimental Takju, showed that the Takjues brewed with the materials combined with wheat flour and steamed potatoes (4:5 or 3.5:7.5) were not significantly different in color, taste and flavor from commercial Takju, However, those with potato flour and wheat flour (1:1 or 7:3) were significantly different from commercial Takju.

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