• Title/Summary/Keyword: Aldehyde compound

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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.

Lipid Oxidation in Dried Shellfish during the Storage (패류 건제품의 저장 중 지질산화)

  • CHO Ho-Sung;CHO Tae-Yong;LEE Kang-Ho;LEE Nahm-Gull;JOO Dong-Sik;KIM Gyeong-Eup;LEE Jong-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.31 no.4
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    • pp.594-598
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    • 1998
  • In this study oxidative deterioration of dried sea mussel and baby clam stored at $4{\pm}2^{\circ}C$ and $25{\pm}2^{\circ}C$ were investigated. Acid value of samples were higher at $25^{\circ}C$ than those at $4^{\circ}C$ throughout the storage period. And it was higher in dried baby clam than in sea mussel regardless of storage temperatures. Peroxide value of dried sea mussel and baby clam stored at $25^{\circ}C$ tended to decrease after 30 and 60 days, respectively. Thiobarbituric acid and carbonyl value of samples stored at $4^{\circ}C$ were higher than those stored at $25^{\circ}C$ throughout the storage period. In case of sea mussel, However they were lower stored at $4^{\circ}C$ than at $25^{\circ}C$ in 30 days. Amino nitrogen increased until 60 days and then decreased in all samples. Fluorescence intensity associated with interaction between carbonyl compound and amino compound was increased with storage temperature and time but it decreased slowly after 60 days.

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Characterization of a Korean Domestic Cyanobacterium Limnothrix sp. KNUA012 for Biofuel Feedstock (토착 남세균 림노트릭스 속 KNUA012 균주의 바이오연료 원료로서의 특성 연구)

  • Hong, Ji Won;Jo, Seung-Woo;Kim, Oh Hong;Jeong, Mi Rang;Kim, Hyeon;Park, Kyung Mok;Lee, Kyoung In;Yoon, Ho-Sung
    • Journal of Life Science
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    • v.26 no.4
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    • pp.460-467
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    • 2016
  • A filamentous cyanobacterium, Limnothrix sp. KNUA012, was axenically isolated from a freshwater bloom sample in Lake Hapcheon, Hapcheon-gun, Gyeongsangnam-do, Korea. Its morphological and molecular characteristics led to identification of the isolate as a member of the genus Limnothrix. Maximal growth was attained when the culture was incubated at 25℃. Analysis of its lipid composition revealed that strain KNUA012 could autotrophically synthesize alkanes, such as pentadecane (C15H32) and heptadecane (C17H36), which can be directly used as fuel without requiring a transesterification step. Two genes involved in alkane biosynthesis-an acyl-acyl carrier protein reductase and an aldehyde decarbonylase-were present in this cyanobacterium. Some common algal biodiesel constituents-myristoleic acid (C14:1), palmitic acid (C16:0), and palmitoleic acid (C16:1)-were produced by strain KNUA012 as its major fatty acids. A proximate analysis showed that the volatile matter content was 86.0% and an ultimate analysis indicated that the higher heating value was 19.8 MJ kg−1. The isolate also autotrophically produced 21.4 mg g−1 phycocyanin-a high-value antioxidant compound. Therefore, Limnothrix sp. KNUA012 appears to show promise for application in cost-effective production of microalga-based biofuels and biomass feedstock over crop plants.