• Title/Summary/Keyword: isoamyl alcohol

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The Measurement and Prediction of the Fire and Explosion Properties of Isoamyl alcohol (이소아밀알코올의 화재 및 폭발 특성치의 측정 및 예측)

  • Ha, Dongmyeong
    • Journal of Energy Engineering
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    • v.25 no.3
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    • pp.34-40
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    • 2016
  • For the safe handling of isoamyl alcohol being used in various ways in the chemical industry, the flash point and the autoignition temperature(AIT) of isoamyl alcohol was experimented. And, the lower explosion limit of isoamyl alcohol was calculated by using the lower flash point obtained in the experiment. The flash points of isoamyl alcohol by using the Setaflash and Pensky-Martens closed-cup testers measured $31^{\circ}C$ and $33^{\circ}C$, respectively. The flash points of isoamyl alcohol by using the Tag and Cleveland open cup testers are measured $43^{\circ}C$and $45^{\circ}C$. The AIT of isoamyl alcohol by ASTM 659E tester was measured as $419^{\circ}C$. The lower explosion limit by the measured flash point $31^{\circ}C$ was calculated as 0.87 vol%. It was possible to predict lower explosion limit by using the experimental flash point or flash point in the literature.

Quality Characteristics of Distilled Liquor Produced Using Ipguk (Koji) During Aging (입국으로 제조한 증류주의 숙성에 따른 품질 특성)

  • Lee, Dae-Hyoung;Jung, Jae-Woon;Lee, Yong-Seon;Seo, Jae-Soon;Park, In-Tae;Kim, Tae-Wan;Kim, Jae-Ho;Ahn, Byung-Hak
    • Korean Journal of Food Science and Technology
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    • v.46 no.6
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    • pp.694-701
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    • 2014
  • This study aimed to investigate the aging of liquor brewed with fermented wine using ipguk (koji) in a jar (JA) and stainless steel container (SC), which are generally used in Korea, and to review the characteristics of the liquors as a function of aging time. The initial alcohol content was 39.8-40.9%, and gradually decreased in the JA and SC as the aging time increased. In the case of fusel alcohols, the n-propanol, isobutanol, and isoamyl alcohol contents did not increase with increasing aging time, in the cases of both JA and SC. The A/B (isoamyl alcohol/isobutyl alcohol) ratio was similar under reduced pressure (RP) and atmospheric pressure (AP), at 1.32-135. The A/P (isoamyl alcohol/n-propanol) and B/P (isobutyl alcohol/n-propanol) ratios were 2.17-2.22 and 1.62-1.68, respectively. During the early stages of distillation, under RP, the isoamyl alcohol content was the greatest, followed by isobutyl alcohol and ethyl palmitate. Under AP, the isoamyl alcohol content was the greatest followed by decanoic acid, ethyl palmitate, and isobutyl alcohol. The highest sensory score under RP, 60 cmHg, was $6.98{\pm}0.28$.

Processing Conditions of Low Salt Fermented Squid and its Flavor Components 1. Volatile Flavor Components of Low Salt Fermented Squid (저염 오징어젓갈 제조 방법 및 향미성분 1. 저염 오징어젓갈의 휘발성 향기성분)

  • 최성희;임성임;허성호;김영만
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.24 no.2
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    • pp.261-267
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    • 1995
  • Low-salted and fermented squid product, squid jeotkal was prepared with the addition of 10% salt and fermented for 50 day at 1$0^{\circ}C$. During fementation of squid, sensory evaluation and changes of volatile components were examined. Volatile flavor components in raw squid and low-salted squid jeotkal were extracted using a rotary evaporating system. The volatile concentrates were identified by GC and GC-MS. Major volatile components of raw squid were methional and 2-methyl-2-propanol. However, alcohols such as propanol, isoamyl alcohol, methionol and phenylethyl alcohol increased during the period of fermentation. The model reaction using microorganism was carried out, in order to confirm formation mechanism ofvolatile flavor compounds of the squid during fermentation. The main volatile components of Pseudomonas sp. D2 model system were isoamyl alcohol and acetoin. Those of Staphylococcus xylosus model system were isoamyl alcohol and phenylacetaldehyde.

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Effects of Isoamyl Acetate Production in Makgeolli According to Fermentation Conditions (막걸리 발효조건에 따른 isoamyl acetate 생성 비교)

  • Song, Choong Sung;Ju, Hyun-Mok;Kim, Jin Man
    • Journal of Life Science
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    • v.30 no.2
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    • pp.162-168
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    • 2020
  • Because of a continual reduction in its domestic market share, the quality of the Makgeolli, a Korean traditional liquor, needs to be upgraded. Among the several options for quality improvement, sufficient organoleptic expression of flavor is very important. We analyzed production changes of isoamyl acetate, which has a banana smell, based on fermentation temperature and sugar content through the cultivation of S. cerevisiae 98-5 KCCM 11396P using generally polished rice. The banana flavor of that fermentation mash was organoleptically high at 20℃, but a larger amount of isoamyl acetate was obtained with a higher sugar content at 10℃, based on analysis by GC-MS. Consequently, sufficient production of banana flavor from isoamyl acetate was based on the concentration of isoamyl alcohol as a substrate compound of isoamyl acetate, and the production depended highly on the maintenance of heat stability, since it is unstable in temperature and the minimized inhibition of alcohol acetyl transferase by unsaturated fatty acids. We also found that production of the flavor component required the addition of sugar and a slightly higher temperature of 20~25℃ at the beginning stage of fermentation, with additional mash fermentation and a gradual decrease in temperature to 10~15℃.

Liquid-Liquid Equilibrium for the Quaternary System Water + Tetrahydrofuran + Butyl Acetate + Isoamyl Alcohol Mixture at 298.15 K and Atmospheric Pressure (1 atm 298.15 K에서 4성분 Water+Tetrahydrofuran+Butyl Acetate+Isoamyl Alcohol 계의 액-액평형)

  • Kim, Young-Kyu;Ok, Dong-Seok;Park, Dong-Won
    • Korean Chemical Engineering Research
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    • v.48 no.5
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    • pp.632-637
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    • 2010
  • Liquid-liquid equilibrium data for the quaternary system water +tetrahydrofuran + butyl acetate + isoamyl alcohol mixture were measured at 298.15 K and atmospheric pressure. Binodal curves, tie-lines, distribution, and selectivity for the quaternary system have been determined in order to investigate the effect of using binary solvents, butyl acetate and isoamyl alcohol, on extracting tetrahydrofuran from aqueous solution. In addition, these experimental tie-line data were also compared with the values predicted by the UNIFAC model. For the quaternary system, an average root-mean-square deviation for the system in 75/25, 50/50, and 25/75 mass ratios as mixed solvents are(3.35, 5.21 and 5.65) %, respectively.

Characteristics of Volatile Compound Adsorption from Alcoholic Model Solution onto Various Activated Carbons (알코올모델용액을 이용한 여러 종류 활성탄의 휘발성화합물 흡착특성)

  • Park, Seung-Kook;Lee, Myung-Soo;Kim, Byung-Ho;Kim, Dae-Ok
    • Food Engineering Progress
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    • v.14 no.3
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    • pp.249-255
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    • 2010
  • Ten commercial activated carbons (ACs) prepared from four different sources (bamboo, wood, peat, and coal) were evaluated for their adsorptive efficiency of six volatile compounds (isoamyl alcohol, hexanal, furfural, ethyl lactate, ethyl octanoate, 2-phenyl ethanol) which were dissolved in a 30% alcoholic model solution. These six volatile compounds are frequently found in alcoholic beverages and possibly contribute to physiological hangover due to their high concentrations. They are also generally regarded as off-flavor compounds at certain levels in alcoholic beverages such as whisky and vodka. Two hundred mL of 30% alcoholic solutions containing these six volatile compounds were treated with 0.2 g of ACs while stirring for 16 hr; the treated solutions were then measured for their adsorptive efficiencies (or removal efficiencies) by gas chromatographic analysis using two different sampling methods (direct liquid injection and headspace-solid phase microextraction). The adsorptive efficiencies of the ACs varied depending on the identity of the volatile compounds and the source material used for making the ACs. Ethyl octanoate, 2-phenyl ethanol, and hexanal were removed at high efficiencies (34-100%), whereas isoamyl alcohol, ethyl lactate, and furfural were removed at low efficiencies (5-13%). AC prepared from bamboo showed a high removal efficiency for isoamyl alcohol, aldehydes (hexanal and furfural), and 2-phenyl ethanol; these major fusel oils have been implicated as congeners responsible for alcohol hangover.

Detection of Cucumber green mottle mosaic virus in Bottle Gourd Seeds by RT-PCR (RT-PCR에 의한 박 종자의 오이녹반모자이크바이러스 검정)

  • Lee, Sook-Kyung;Song, Wan-Yeob;Kim, Hyung-Moo
    • Research in Plant Disease
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    • v.10 no.1
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    • pp.53-57
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    • 2004
  • Cucumber green mottle mosaic virus (CGMMV) was a major pathogen of watermelon and had affected seriously to watermelon production in Korea. Rapid and sensitive detection method of CGMMV associated with bottle gourd (Lagenafia siceraria) seeds was developed by using RT-PCR in this study. A pair of primeri Wmfl and Wmrl, specific for CGMMV was designed from coat protein gene sequences of CGMMV-W and used for amplifying 420 bp product in RT-PCR. To simplify the virus extraction procedure and reduce an inhibitor from the extract for the RT-PCR, some methods using ethanol precipitation, double filtration, polyethylene glycol precipitation and phenol/chloroform/isoamyl alcohol extraction procedure were compared and the phenol/chloroform/isoamyl alcohol extraction procedure was selected by its enhanced sensitivity. This detection method using the selected extraction step and the primers for RT-PCR could reliably detect an infected level of one CGMMV-infested seed in 1,000 seeds. This rapid and sensitive RT-PCR assay provides auseful tool for the specific detection of CGMMV in bottle gourd seed samples containing high levels of back-ground inhibitors.

Microbiological Characteristics and Volatile Components of Deastringent Persimmon Vinegar

  • Hur, Sung-Ho;Lee, Ho-Jae;Lee, Tae-Shik;Lee, Won-Koo;Hong, Jeong-Hwa
    • Preventive Nutrition and Food Science
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    • v.3 no.3
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    • pp.230-233
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    • 1998
  • Acetic acid producing bacteria were isolated from deastringent persimmon vinegar and the major bacterium was identified using morphological and biochemical tests. Acetobacter sp. AH-1 was motile, gram negative rod with catalase positive and oxidase negative. The strain can grow up to 5 % ethanol and 2% NaCl as well as 25% glucose. Optimum temperature and pH for growth were 3$0^{\circ}C$ and 5.0, respectively. Volatile constituents of persimmon vinegar were analyzed by purge and trap sampling . Acetic acid adn alcohol were the largest volatile compounds quantitiatively in persimmon vinegar. Among alcohols, 20methyl-1-propanol, isoamyl alcohol and amyl alcohol were detected. Isovaleradehyde and benzaldehyde for aldehyde, isoamyl acteate, ethyl formate, propyl aceetate, and ethyl acetate for esters were likely to contribute to persimmon vivegar flavor.

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Volatile Flavor Components in the Mashes of Takju Prepared Using Different Yeasts (효모종류를 달리한 탁주 술덧의 휘발성 향기성분)

  • Lee, Heung-Sook;Lee, Taik-Soo;Noh, Bong-Soo
    • Korean Journal of Food Science and Technology
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    • v.39 no.6
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    • pp.593-599
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    • 2007
  • In this study, we examined the volatile flavor components in the mashes of takju prepared using different yeasts such as Saccharomyces coreanus, S. ellipsoideus, S. carlsbergensis, S. cerevisiae (Baker's yeast), and S, rouxii by GC and GC-MS. Fourteen alcohols, 13 esters, 5 acids, 3 aldehydes, 7 amines, and 2 other compounds were identified in the mash after 6 days of fermentation. On day 6, the takju fermented by S. coreanus had the greatest variety of volatile flavor components. Fifteen flavor components, including ethanol, isobutyl alcohol, isoamyl alcohol, methyl pentanol, 1,3-butanediol, 3-methylthio-1-propanol, benzeneethanol, ethyl lactate, acetic acid, acetaldehyde, and 1,3-cyclohexane diamine, were typically detected in all the treatments. The relative peak areas of the volatile components were as follows: alcohols (96.758-99.387%), esters (0.081-0.968%), acids (0.040-0.640%), aldehydes (0.266-0.959%), and amines (0.011-0.047%). In particular, 1-propanol, isobutyl alcohol, 3-methyl-1-butanol, 2,3-butanediol, trimethyl benzylalcohol, heptene-2,4-diol, ethyl lactate, diethyl succinate, ethyl nonanoate, methyl hexadecanoate, linoleic acid, hexadecanoic acid, and acetaldehyde were hish in the takju made by S. coreanus. Also, ethyl stearate was high in the takju made by S. carlsbergensis, and hexanoic acid was high in the takju made by S. cerevisiae. Finally, methyl pentanol, 1,3-butanediol, 3-methylthio-1-propanol, benzene ethanol, ethyl octadecanoate, acetic acid, pentanal, and 1,3-cyclohexane diamine were high in the takju made by S. rouxii.

Feasibility of Brewing Makgeolli Using Pichia anomala Y197-13, a Non-Saccharomyces cerevisiae

  • Kim, Hye Ryun;Kim, Jae-Ho;Bai, Dong-Hoon;Ahn, ByungHak
    • Journal of Microbiology and Biotechnology
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    • v.22 no.12
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    • pp.1749-1757
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    • 2012
  • Makgeolli is a traditional rice wine favored by the general public in Korea. This study investigated the fermentation and sensory characteristics of using wild yeast strains for brewing makgeolli. A non-Saccharomyces cerevisiae strain was isolated from nuruk and termed Y197-13. It showed 98% similarity to Pichia anomala and had an optimal growth temperature of $25^{\circ}C$. Makgeolli was manufactured using koji, jinju nuruk, and improved nuruk as fermentation agents. Y197-13 makgeolli brewed with koji had alcohol and solids contents of 11.1% and 13.9%, respectively. Sweet sensory characteristics were attributed to residual sugars in makgeolli with 6% alcohol. The makgeolli had a fresh sour taste and carbonated taste. Volatile component analysis showed the isoamyl alcohol, phenylethyl alcohol, isoamyl acetate, and fatty acid, including ethyl oleate and ethyl linoleate, relative peak area was higher in Y197-13 makgeolli than in makgeolli with Saccharomyces cerevisiae. These results suggest the wild yeast, Y197-13, as a candidate for brewing makgeolli.