• Title/Summary/Keyword: ketones

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Identification and Antibacterial Activity of Volatile Flavor Components of Cordyceps Militaris

  • Park, Mi-Ae;Lee, Won-Koo;Kim, Man-Soo
    • Preventive Nutrition and Food Science
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    • v.4 no.1
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    • pp.18-22
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    • 1999

  • Flavor characteristics of raw Cordyceps militaris significatntly different from those of dried one. In the case of raw Cordyceps militaris , major flavor components were composed of 5 alcohols, 3 ketones, 4 phenols, 9 alkanes , and 3 alkenes. The major alcohol was 1-octen-3-ol(22.56%, 1147.3% ng/ml), which contributed to the characteristic green flavor. Ketones (3-ocatone, inparticular )were present in the highest concentration in raw Cordyceps militaris . In contrast, major flavor components of dried Cordyceps militaris were composed of 4 alcohols, 4 ketones, 3 furans, 4 pyrizines, 2 dithiazines, 5 phenols , 8alkenes , 17 alkanes, and 8 fatty acids. Dried Cordyceps militaris had unique sweet aroma of sesame as wella s a milky flavor. Green or fruit flavor were rarely detected . In alkanes , 10 cosanes, component fo wax were present. Typical flavor components of alkanes such as $\beta$-caryophyllen and Δ-cadinene were also detected. Fatty acids of dried Cordyceps militaris ranged from myristic acid (14 :0) to linoleic acid (18 ; 2). The sweet aroma of dried Cordyceps militaris was mostly due to pryazines, dithaiazines, and furans. Two dithaizines were identified and characteristics of these flavor components was a roasted bacon flavor. Strong antibacterial acitivity was observed toward Vibrio spp. such as V. vulnificus, V.cholerae, V. parahaemlyticus. Relatively high antibacterial acitivity was shown toward Bacillus subtilis , B,cereus, Staphyllococcus aureus, and Corynebacterium xerosis.

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Pyrolysis/GC-Mass Spectrometry Analysis for Rapid Identification of Volatile Flavour Compounds of Accelerated Ripened Cheddar Cheese and Enzyme-Modified Cheese (단기숙성치즈 및 EMC 치즈의 휘발성 풍미성분 신속분석방법으로서 Pyrolysis/GC-Mass Spectrometry의 이용)

  • ;;;S.S.B. Haileselassie;V.A. Yaylayan;B.H. Lee
    • Food Science of Animal Resources
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    • v.21 no.3
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    • pp.256-264
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    • 2001

  • Pyrolysis/GC-mass spectrometry(Hewlet-Packard 5890GC/mass selective detector, 5971 BMSD), interfaced to a CDS Pyroprobe 1500 was optimized for rapid analysis of flavour compounds in Cheddar cheese. Twenty flavour compounds, including aldehydes(4), ketones(4), fatty acids(10), alcohol(1), and hydrocarbon(1), were identified from Cheddar cheeses. In total, Twenty-three flavour compounds aldehydes(2), ketones(8), alcohols(3), fatty acids(7), lactone(1), benzene derivative(1) and amide(1) were identified from two samples of accelerated-ripened Cheddar cheese treated with the proteolytic enzymes of Lactobacillus casei LGY. In total, Twenty-one flavour compounds; aldehydes(2), ketones(5), alcohols(2), fatty acids(11), and lactone(1) were identified from enzyme-modified cheese(EMC) treated with the combination of the proteolytic enzymes of Lactobacillus casei LGY and commercial endopeptidase or lipase. However, All the flavour compounds identified by pyrolysis/GC/MS in samples of ARC and EMC were not determined whether they are recognized as typical Cheddar flavour or not. More studies were requested on the development of methods for a rapid and convienent analysis of dairy fermented products using pyrolysis/GC-mass spectrometry.

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Prediction of Upper Explosion Limits (UEL) of Acids and Ketones by Using Setaflash Tester (Setaflash 장치를 이용한 산류와 케톤류의 폭발상한계 예측)

  • Ha, Dong-Myeong
    • Fire Science and Engineering
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    • v.25 no.2
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    • pp.114-119
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    • 2011

  • Explosion limit and flash point are the major combustion properties used to determine the fire and explosion hazards of the flammable substances. In this study, in order to predict upper explosion limits (UEL) for acids and ketones, the upper flash point of these were measured under the VLE (vaporliquid equilibrium) state by using Setaflash closed cup tester (ASTM D3278). The UELs calculated by Antoine equation by using the experimental upper flash point are usually lower than the several reported UELs. From the given results, using the proposed experimental and predicted method, it is possible to research the upper explosion limits of the other flammable substances.

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