• Title/Summary/Keyword: headspace-gas chromatography

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Germination-Induced Changes in Flavoring Compound Profiles and Phytonutrient Contents in Scented Rice (향미벼의 발아 전 후 향기 성분 및 기능성 지질성분 함량의 변화)

  • Mahmud, MM Chayan;Das, Animesh Chandra;Lee, Seul-Ki;Kim, Tae-Hyeong;Oh, Yejin;Cho, Yoo-Hyun;Lee, Young-Sang
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.61 no.4
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    • pp.242-250
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    • 2016
  • Although rice has been cultivated as a major food crop for approximately 5,000 years, the interest of customers in 'scented rice' is a recent trend in the Korean market. As a part of developing a germinated scented rice variety, the newly bred scented rice variety 'Cheonjihyang-1 se' was germinated for 24 h, and changes in profiles of flavor-related volatiles, lipophilic phytonutrients, and fatty acids were investigated. The profiling of volatile compounds by using a headspace-gas chromatography-mass spectrometry (HS-GC-MS) revealed a total of 56 odor-active flavoring compounds; 52 at the pre-germination stage, 51 at the post-germination stage, and 47 common at both stages. The major flavoring compounds were nonanol and benzene, which constituted 11.5% and 6.6%, respectively, of the total peak area in pre-germinated rice, and 19.4% and 6.5%, respectively, in post-germinated rice. Germination induced an increase in 13 flavoring compounds, including 3,3,5-trimethylheptane and 1-pentadecene, which increased by 763 and 513%, respectively by germination. However, we observed a germination-induced decrease in most of the other flavoring compounds. Especially, the most important scented rice-specific popcorn-flavoring compound, 2-acetyl-1-pyrroline, showed 89% decrease due to germination. Furthermore, the germination of scented rice induced a decrease in the content of various phytonutrients. For example, the total contents of phytosterols, squalene, and tocols decreased from 207.97, 31.74, and $25.32{\mu}g\;g^{-1}$ at pre-germination stage down to 136.66, 25.12, and $17.76{\mu}g\;g^{-1}$, respectively at post-germination stage. The fatty acid compositions were also affected by germination. The composition of three major fatty acids, linoleic, oleic, and palmitic acids, increased from 36.6, 34.2, and 24.4%, respectively, at the pre-germination stage to 37.9, 36.9, and 20.7%, respectively, at the post-germination stage. All these results suggested significant changes in the flavor-related compounds and phytonutrients of the scented rice variety 'Cheonjihyang-1 se' during the process of germination, and subsequently the need for developing a more precise process of germination to enhance the flavor and nutritional quality of the germinated scented rice products.

Evaluation of Odors and Odorous Compounds from Liquid Animal Manure Treated with Different Methods and Their Application to Soils (액상 가축분뇨의 처리 및 토양환원에 따른 악취 및 악취물질의 평가)

  • 고한종;최홍림;김기연;이용기;김치년
    • Journal of Animal Science and Technology
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    • v.48 no.3
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    • pp.453-466
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    • 2006
  • To comply with stricter regulations provoked by increasing odor nuisance, it is imperative to practice effective odor control for sustainable livestock production. This study was conducted to assess odor and odorous compounds emitted from liquid animal manure with different treatment methods such as Fresh Manure(without treatment, FM), Anaerobic Digestion(AD) and Thermophilic Aerobic Digestion(TAD) and their application to soil. Air samples were collected at the headspace of liquid manure, upland and paddy soil, and analyzed for odor intensity and offensiveness using an olfactometry; odor concentration index using odor analyser; nitrogen-containing compound such as ammonia(NH3) using fluorescence method; and sulfur containing compounds such as hydrogen sulfide(H2S), methyl mercaptan(MeSH), dimethyl sulfide(DMS) and dimethyl disulfide(DMDS) using gas chromatography-pulsed flame photometric detector, respectively. Odor intensity, offensiveness and concentration index from TAD liquid manure was statistically lower than those from FM and AD(p<0.01). Mean concentrations of H2S, MeSH, DMS, DMDS and NH3 were 65.93ppb, 18.55ppb, 5.26ppb, 0.33ppb and 10.57ppm for liquid manure with AD; and 5.15ppb, 0.97ppb, 0.80ppb, 0.56ppb and 1.34ppm for liquid manure with TAD, respectively. More than 60% of malodorous compounds related to nitrogen and sulfur were removed by heterotrophic microorganisms during TAD treatment. When liquid manure was applied onto upland and paddy soil, NH3 removal efficiencies ranged from 51 to 94% and 22 to 91% for AD and TAD liquid manure, respectively. The above results show that liquid manure with TAD is superior to AD and FM with respect to the odor reduction and odor problem caused by land applied liquid manure is directly related to the degree of odor generated by the manure treatment method.