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721.
Analysis of volatile compounds released during the grinding of roasted coffee beans using solid-phase microextraction 总被引:1,自引:0,他引:1
Akiyama M Murakami K Ohtani N Iwatsuki K Sotoyama K Wada A Tokuno K Iwabuchi H Tanaka K 《Journal of agricultural and food chemistry》2003,51(7):1961-1969
A dynamic solid-phase microextraction (SPME) method to sample fresh headspace volatile compounds released during the grinding of roasted coffee beans was described and the analytical results using gas chromatography/mass spectrometry (GC/MS) and GC/olfactometry (GC/O) were compared to those of the conventional static SPME sampling methods using ground coffee. Volatile compounds released during the grinding of roasted coffee beans (150 g) were obtained by exposing the SPME fiber (poly(dimethylsiloxane)/divinylbenzene, PDMS/ DVB) for 8 min to nitrogen gas (600 mL/min) discharged from a glass vessel in which the electronic coffee grinder was enclosed. Identification and characterization of volatile compounds thus obtained were achieved by GC/MS and GC/O. Peak areas of 47 typical coffee volatile compounds, separated on total ion chromatogram (TIC), obtained by the dynamic SPME method, showed coefficients of variation less than 5% (n = 3) and the gas chromatographic profile of volatile compounds thus obtained was similar to that of the solvent extract of ground coffee, except for highly volatile compounds such as 4-hydroxy-2,5-dimethyl-3(2H)-furanone and 4-ethenyl-2-methoxyphenol. Also, SPME dilution analysis of volatile compounds released during the grinding of roasted coffee beans showed linear plots of peak area versus exposed fiber length (R (2) > 0.89). Compared with those of the headspace volatile compounds of ground coffee using GC/MS and GC/O, the volatile compounds generated during the grinding of roasted coffee beans were rich in nutty- and smoke-roast aromas. 相似文献
722.
Supriyadi Suhardi Suzuki M Yoshida K Muto T Fujita A Watanabe N 《Journal of agricultural and food chemistry》2002,50(26):7627-7633
During the maturation of snake fruit (Salacca edulis Reinw) Pondoh, the contents of sucrose, glucose, fructose, and volatile compounds changed drastically. The glucose, fructose, and volatile compounds contents showed their maximum levels at the end of maturation; however, the sucrose content decreased. During maturation, the flesh firmness tended to increase; however, at the end of maturation (6 months), the flesh became soft. The major volatile aroma in solvent-assisted flavor evaporation (SAFE) and solvent extracts were identified to be methyl esters of butanoic acids, 2-methylbutanoic acids, hexanoic acids, pentanoic acids, and the corresponding carboxylic acids. Furaneol (4-hydroxy-2,5-dimethyl-3(2H)-furanone) was also identified as a minor aroma constituent in the SAFE residue. The methyl esters were found to increase dramatically during stages 4-6 (5-6 months after the pollination) to exceed the amounts of carboxylic acids, whereas the acid amount increased gradually until stage 5 (5.5 months after the pollination) to reach the maximum at stage 6 (6 months after the pollination). 相似文献
723.
The objective of this study was to develop a technique for determining the country of origin of rice in the Japanese market. The rice samples included a total of 350 products grown in Japan (n = 200), the United States (n = 50), China (n = 50), and Thailand (n = 50). In this study, (87)Sr/(86)Sr and Pb isotope ((204)Pb, (206)Pb, (207)Pb, and (208)Pb) ratios and multielement concentrations (Al, Fe, Co, Ni, Cu, Rb, Sr, and Ba) were determined by high-resolution inductively coupled plasma mass spectrometry. By combining three chemometric techniques based on different principles and determination criteria, the countries of origin of rice were determined. The predictions made by 10-fold cross-validation were around 97% accurate. The presented method demonstrated the effectiveness of determining the geographic origin of an agricultural product by combining several chemometric techniques using heavy element isotope ratios and multielement concentrations. 相似文献
724.
Tamura H Fujita A Steinhaus M Takahisa E Watanabe H Schieberle P 《Journal of agricultural and food chemistry》2011,59(18):10211-10218
Eleven odor-active thiols, namely, 2-methyl-1-propene-1-thiol, (Z)-3-methyl-1-butene-1-thiol, (E)-3-methyl-1-butene-1-thiol, (Z)-2-methyl-1-butene-1-thiol, (E)-2-methyl-1-butene-1-thiol, 2-methyl-3-furanthiol, 3-mercapto-2-pentanone, 2-mercapto-3-pentanone, 4-mercapto-3-hexanone, 3-mercapto-3-methylbutyl formate, and 2-methyl-3-thiophenethiol, recently identified in an extract prepared from white sesame seeds, were quantitated in sesame using stable isotope dilution analyses. For that purpose, the following deuterium-labeled compounds were synthesized and used as internal standards in the quantitation assays: [2H6]-2-methyl-1-propene-1-thiol, [2H3]-(E)- and [2H3]-(Z)-2-methyl-1-butene-1-thiol, [2H3]-2-methyl-3-furanthiol, [2H2]-3-mercapto-2-pentanone, [2H3]-4-mercapto-3-hexanone, [2H6]-3-mercapto-3-methylbutyl formate, and [2H3]-2-methyl-3-thiophenethiol. On the basis of the results obtained, odor activity values (OAVs) were calculated as ratio of the concentration and odor threshold of the individual compounds in cooking oil. According to their high OAVs, particularly the 3-methyl-1-butene-1-thiols (OAV: 2400) and the 2-methyl-1-butene-1-thiols (OAV: 960) were identified as the most odor-active compounds in pan-roasted white sesame seeds. These compounds were therefore suggested to be mainly responsible for the characteristic but rather unstable sulfury aroma of freshly pan-roasted white sesame seeds. 相似文献
725.
Kazuya Koizumi Nobuhiro Kuboyama Kohtaro Tomono Akira Tanaka Aiko Ohki Hitoshi Kohno Ko Wakabayashi Peter Bger 《Pest management science》1999,55(6):642-645
New fluoroalkyl-substituted 1,3,5-triazine derivatives were synthesized and screened for herbicidal activity using a greenhouse pot test. Surprisingly, a series of 2-alkyl-4-fluoroalkyl-6-aralkylamino-1,3,5-triazines e.g. 6-(4-bromobenzylamino)-2-methyl-4-trifluoromethyl-1,3,5-triazine was found to possess strong pre- and post-emergence herbicidal activities, although the conventional herbicidal 1,3,5-triazines generally should have a 2-substituted-4,6-diamino-1,3,5-triazine structure for herbicidal activity. Our compounds show strong Photosynthetic Electron Transport inhibitory activity (PI50 c 7). Although their herbicidal effect is considered to be caused by a process similar to that for the conventional 1,3,5-triazine herbicide atrazine, they can control atrazine-resistant Chenopodium album effectively, and will thus form promising trial compounds for new triazine herbicide design. 相似文献
726.
Takashi OKURA Hiroki OTOMO Shoko SUZUKI Yuji ONO Akira TANENO Eiji OISHI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(11):1686
Infectious bursal disease (IBD) causes severe economic damage to the poultry industry worldwide. To prevent IBD virus (IBDV) infection, live virus vaccines have been widely used in chickens having wide-ranging levels of maternally derived antibodies. But, the risks of infection with other pathogens because of lesions related to atrophy of the bursa of Fabricius in vaccinated chickens are a concern. To resolve the problems, a recombinant turkey herpesvirus (HVT) vaccine expressing IBDV-VP2 protein (rHVT-IBD) has been developed. However, the induction of neutralizing antibodies by rHVT-IBD against a virulent IBDV might be delayed compared with that by the live IBD vaccine, leading to the high risks of IBDV infection for young chickens. To find the best selection of IBDV vaccine for the onset of immunity, we examine the protective efficacy of a novel in ovo-attenuated live IBDV (IBD-CA) vaccine and the rHVT-IBD vaccine in young chickens challenged with a very virulent IBDV (vvIBDV) strain. We show that the protective efficacy of IBD-CA vaccine was higher than that of the rHVT-IBD vaccine in 14-day-old chickens challenged with the vvIBDV strain, leading to the risk of IBDV infection for young chickens when vaccinated with rHVT-IBD. Our results suggest that farmers should select the best vaccines to maximize vaccine efficacy in consideration of the vaccine characteristics, prevalence levels of IBDV in the areas, and initial MDA levels of the chickens since the attenuated live and recombinant vaccines play a role in the different vaccine efficacies. 相似文献
727.
ABSTRACT: The optimal water temperature in seed germination and the upper critical water temperature in seedling growth were determined for Zostera marina collected from Ise Bay, Japan. The relationship between the seed germination rates and seed storage period (0, 30 and 60 days at 0°C) was also examined. The optimal water temperature for seed germination was in the range from 10 to 15°C regardless of the storage periods, in which germination rates ranged from 35 to 57%. Seedlings grown from seed up to 10 cm in total length were cultured for 1 week under various water temperatures to measure their relative growth rates. The optimal water temperature in growth was in the range from 20 to 25°C; relative growth rates ranged from 2.0 to 2.6%. Seedlings could survive up to a water temperature of 28°C, but most seedlings withered at 29 or 30°C. The optimal water temperatures for seed germination and seedling growth were related to the seasonal changes of water temperature at the sampling site. Although seedlings were rarely observed in the field in summer, they can grow at temperatures as high as 28°C. Therefore, Z. marina may extend its distribution as far as where the summer water temperature is lower than 28°C. 相似文献
728.
729.
Akira GOTO Masaaki TAGAMI Fumiki KATO Tsukasa SUZUKI Takashi YAMAGA Harutaka MURASE Fumio SATO Munkhtuul TSOGTGEREL Tadamasa NIIKURA Tomoe MORIYAMA Akiko CHIBA Ken-ichi WATANABE Nao TSUZUKI Yasuo NAMBO 《Journal of Equine Science》2021,32(4):147
We performed a standing hand-assisted laparoscopic ovariectomy in a draft mare that presented with high serum anti-Müllerian hormone (AMH) level and had an enlarged single cystic ovary. Histopathological examination revealed no tumor cell proliferation in the ovary, but the presence of a large ovarian cyst was confirmed. In the diagnosis of abnormal ovaries in mares, a comprehensive assessment should be performed, including the monitoring of ovarian morphology and biomarkers over time, to determine the disease prognosis and treatment plan. The case of this mare with a nonneoplastic abnormal ovary and increased serum AMH level was rare. We suggest that standing hand-assisted laparoscopic ovariectomy is useful for the removal of large ovaries in draft mares. 相似文献
730.
Retention behavior of size and aluminum components in handsheets prepared in rosin soap size-alum systems 总被引:2,自引:0,他引:2
Handsheets were prepared with rosin soap size and aluminum sulfate under various conditions, and the retention behavior of the rosin size and aluminum components in the handsheets was studied. Pyrolysis-gas chromatography and X-ray fluorescence analysis were used to determine the size and aluminum contents in the handsheets, respectively. When the addition level of rosin soap size varied from 0% to 4% and that of aluminum sulfate was fixed at 2%, the rosin size content increased with the increase in the size addition level, whereas aluminum and calcium contents were roughly constant. Under these conditions, handsheets prepared from fines-free pulp had aluminum contents less than those for the original beaten pulp, probably because the former pulp had a carboxyl content less than that of the latter pulp. Not only the conventional rosin retention mechanism but also mechanism proposed below must exist in the rosin soap size-alum systems. That is, some aluminum compounds originating from aluminum sulfate are adsorbed on pulp fibers immediately after the aluminum sulfate addition. These adsorbed aluminum compounds form cationic sites on pulp fibers, and free rosin acid components with anionic charges are then adsorbed onto the cationic sites of pulp fibers at the wet-end.This research was presented in part at the 46th annual meeting of the Japan Wood Research Society, Kumamoto, April 1996 相似文献